JP2021045025A - Diagnostic device, distributed power generation system, and diagnostic method - Google Patents

Abstract

To provide a diagnostic device, a distributed power generation system, and a diagnostic method, for diagnosing a current detection unit.SOLUTION: A distributed power generation system comprises: a distributed power generation device connected to a system power supply via a power line including a first phase power line, a neutral line, and a second phase power line; a current detection unit including first and second current detection units connected to the first and second phase power lines, respectively; and a load including a first phase load with which connection of the first phase power line can be selected, a second phase load with which connection of the second phase power line can be selected, and a third load arbitrarily connected to the first phase power line and the second phase power line. The distributed power generation system comprises a diagnostic device for diagnosing whether or not the current detection unit is normal, the diagnostic device comprising a diagnosis propriety determination unit that when the absolute value of a load variation on the power line is smaller than a predetermined load variation determination value Xu or Xw, determines that the current detection unit can detect a current value for diagnosing whether or not the current detection unit is normal.SELECTED DRAWING: Figure 4

Description

The present invention relates to a diagnostic device, a distributed power generation system, and a diagnostic method of a current detection unit provided in a power line connecting a distributed power generation device and a grid power source.

In the distributed power generation system of Patent Document 1, the distributed power generation device and the system power supply are connected by a power line including an R-phase line, an N-phase line, and a T-phase line. An R-phase sensor and a T-phase sensor are attached to the R-phase wire and the T-phase wire as current sensors, respectively. Further, as a power load, the R-phase load is connected to the R-phase wire and the N-phase wire, and the T-phase load is connected to the T-phase wire and the N-phase wire. When diagnosing whether or not the R-phase sensor is normal, the magnitude and direction of the current flowing through the R-phase line is detected by the R-phase sensor by energizing the R-phase load. Similarly, when diagnosing whether or not the T-phase sensor is normal, the T-phase load is energized and the magnitude and direction of the current flowing through the T-phase line is detected by the T-phase sensor. The diagnosis of normality includes the diagnosis of the connection state such as the mounting direction and mounting position of the current sensor.

In Patent Document 1, each of the R-phase sensor and the T-phase sensor is diagnosed a plurality of times. As a result, even if the current sensor cannot be diagnosed once, it is possible to guarantee the acquisition of the judgment value by performing the diagnosis a plurality of times.
For example, when the timing of power supply to the R-phase load for a predetermined time and the timing of power supply to the household load other than the R-phase load match, the current value detected by the R-phase sensor is the R-phase. The value will be different from the current value based on the supply of power to the load only. Therefore, it is not possible to obtain a judgment value for diagnosing the R-phase sensor, and it is not possible to correctly grasp whether or not the R-phase sensor is normal. According to the configuration of Patent Document 1, since the R-phase sensor is diagnosed a plurality of times, even if the current value based on the power supply only to the R-phase load cannot be measured by the R-phase sensor at a certain diagnosis, For example, it is possible to obtain the necessary judgment value at the time of diagnosis from the next time onward. Similarly, the acquisition of the judgment value can be guaranteed for the acquisition of the current value by the T-phase sensor.

Japanese Unexamined Patent Publication No. 2015-122819

However, even when the current value is measured a plurality of times as in Patent Document 1, the R-phase load or the T-phase load may be applied depending on the usage conditions of the domestic load other than the R-phase load or the T-phase load, for example. In some cases, it may not be possible to deviate the timing of power supply from the timing of power supply to, for example, a domestic load other than the R-phase load or the T-phase load. In this case, the R-phase sensor or the T-phase sensor cannot acquire a determination value for determining whether or not it is normal. Therefore, since the state of the R-phase sensor or the T-phase sensor may be erroneously diagnosed, improvement in the diagnosis of the current detection unit is desired.
Further, it is desired to improve the diagnosis of the current detection unit in that it can be efficiently diagnosed after the distributed power generation system is installed or during regular maintenance.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a diagnostic device, a distributed power generation system, and a diagnostic method for diagnosing a current detection unit.

The characteristic configuration of the diagnostic apparatus according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic device that diagnoses whether the current detector is normal or not.
It is determined whether or not the load fluctuation determination condition in which the absolute value of the load fluctuation in the power line is less than the predetermined load fluctuation determination value is satisfied, and when the load fluctuation determination condition is satisfied, the current detection unit performs the current detection unit. The point is that it is provided with a diagnostic availability determination unit that determines that the current value for diagnosing whether or not is normal can be detected.

When diagnosing whether or not the current detection unit is normal, the first phase load is connected to the first phase power line, or the second phase load is connected to the second phase power line. The first phase load and the second phase load are loads that consume surplus power generated by, for example, a distributed power generation device. Further, a third load is optionally connected to the first phase power line and the second phase power line. The third load is various electric devices such as a television, a refrigerator, and a washing machine. Here, in the following, it is assumed that the third load is connected to each of the first phase power line and the second phase power line. In this case, when diagnosing the current detection unit, the first phase load and the third load are connected to the first phase power line, or the second phase load and the third load are connected to the second phase power line. The load is connected. Therefore, in the first phase power line, the load fluctuation occurs because the first phase load and the third load consume the power from the system power supply. Further, in the second phase power line, load fluctuation occurs because the second phase load and the third load consume the power from the system power supply.
The current detection unit is normal, for example, when a predetermined diagnostic condition is satisfied.

When diagnosing whether or not the current detection unit is normal, it is necessary to be able to grasp whether or not the load fluctuation due to the first phase load connected to the first phase power line is occurring in the first phase power line. If a large load fluctuation occurs in the first phase power line when the first phase load is connected to the first phase power line, and a large load fluctuation also occurs in the second phase power line, the first phase power line and the first phase power line It is not possible to ascertain whether or not the load fluctuation of any of the second phase power lines is caused by connecting the first phase load to the first phase power line. In this case, for example, in a situation where it is not possible to diagnose whether the first current detection unit is connected to the first phase power line or the second phase power line, the first current detection unit is connected to the second phase power line. An erroneous diagnosis occurs as to whether or not the first current detection unit is normal, such as a situation in which it is diagnosed as being present. Similarly, when a phase 2 load is connected to a phase 2 power line and a large load fluctuation occurs in both the phase 1 power line and the phase 2 power line, the load of either the phase 1 power line or the phase 2 power line It is not possible to grasp whether the fluctuation is caused by connecting the second phase load to the second phase power line. In this case, similarly to the above, an erroneous diagnosis occurs as to whether or not the second current detection unit is normal.

The reason for this situation is that the third load is connected to the first phase power line and the second phase power line, and the load fluctuation due to the third load occurs significantly in the first phase power line and the second phase power line. Conceivable.

According to this feature configuration, when the absolute value of the load fluctuation in the power line is less than the load fluctuation determination value, that is, when the absolute value of the load fluctuation due to the third load connected to the power line is small, the current detector is operated. Determine that the current value for diagnosis can be obtained. As a result, when the first phase load is connected to the first phase power line for diagnosing the current detection unit, a large load fluctuation occurs in the first phase power line, but the third load connected to the second phase power line It is possible to suppress giving a large load fluctuation to the second phase power line. Similarly, when the second phase load is connected to the second phase power line for diagnosing the current detection unit, a large load fluctuation occurs in the second phase power line, but the third load connected to the first phase power line It is possible to suppress giving a large load fluctuation to the first phase power line.

Therefore, in the first phase power line to which the first phase load is connected, the load fluctuation is larger than that in the second phase power line in which the second phase load is disconnected, and the behavior of the load fluctuation of the first phase power line and the second phase The behavior of the load fluctuation of the power line becomes different. Therefore, it is possible to distinguish between the first phase power line and the second phase power line. Then, it is possible to detect whether or not the first current detection unit is normal depending on whether or not the first current detection unit detects a large load fluctuation in the first phase power line. Similarly, in the second phase power line to which the second phase load is connected, a larger load fluctuation occurs than in the first phase power line in which the first phase load is disconnected, but the second current detector detects the large load fluctuation. Whether or not the second current detection unit is normal can be detected depending on whether or not it is detected. As a result, it is possible to suppress an erroneous diagnosis as to whether or not the current detection unit is normal.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The load fluctuation determination value includes a first load fluctuation determination value, which is a standard for determining an absolute value of load fluctuation in the first phase power line, and a standard for determining an absolute value of load fluctuation in the second phase power line. The second load fluctuation judgment value is included,
The load fluctuation determination condition includes a first load fluctuation determination condition for determining whether or not the current value can be detected by the second current detection unit, and a determination as to whether or not the first current detection unit can detect the current value. 2nd load fluctuation judgment condition for
The diagnostic approval / disapproval determination unit
When it is determined that the absolute value of the load fluctuation in the second phase power line is less than the second load fluctuation determination value and the second load fluctuation determination condition is satisfied, the first current detection unit normalizes the first current detection unit. Determined that it is possible to detect the current value for diagnosing whether or not
On the other hand, when it is determined that the absolute value of the load fluctuation in the first phase power line is less than the first load fluctuation determination value and the first load fluctuation determination condition is satisfied, the second current detection unit performs the second current detection unit. The point is to determine that it is possible to detect the current value for diagnosing whether or not it is normal.

When diagnosing the first current detection unit, the first phase load is connected to the first phase power line, and the second phase load is not connected to the second phase power line. On the other hand, when diagnosing the second current detection unit, the second phase load is connected to the second phase power line, and the first phase load is not connected to the first phase power line. The third load is arbitrarily connected to the first phase power line and the second phase power line, and here, it is assumed that the third load is connected to each of the first phase power line and the second phase power line.

According to this feature configuration, when diagnosing the first current detection unit, when the absolute value of the load fluctuation in the second phase power line is less than the second load fluctuation determination value, that is, it is connected to the second phase power line. When the load fluctuation due to the third load is small, it is determined that the current value for diagnosing the first current detection unit can be acquired. In this case, if the first phase load is connected to the first phase power line in order to diagnose the first current detection unit, a large load fluctuation occurs in the first phase power line, but the third load connected to the second phase power line. Can suppress giving a large load fluctuation to the second phase power line. Therefore, for example, in a situation where it is not possible to diagnose whether the first current detection unit is connected to the first phase power line or the second phase power line, the first current detection unit is connected to the second phase power line. It is possible to suppress an erroneous diagnosis as to whether or not the first current detection unit is normal, such as a situation in which the diagnosis is made.

Similarly, when diagnosing the second current detection unit, when the absolute value of the load fluctuation in the first phase power line is less than the first load fluctuation determination value, that is, the third connected to the first phase power line. When the load fluctuation due to the load is small, it is determined that the current value for diagnosing the second current detection unit can be acquired. In this case, if the second phase load is connected to the second phase power line in order to diagnose the second current detector, a large load fluctuation occurs in the second phase power line, but the third load connected to the first phase power line. Can suppress giving a large load fluctuation to the first phase power line. Therefore, for example, in a situation where it is not possible to diagnose whether the second current detection unit is connected to the first phase power line or the second phase power line, the second current detection unit is connected to the first phase power line. It is possible to suppress an erroneous diagnosis as to whether or not the second current detection unit is normal, such as a situation in which the diagnosis is made.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The first load fluctuation determination value is set within the range of load fluctuation due to the power consumed by the second phase load, and the second load fluctuation determination value is a load due to the power consumed by the first phase load. The point is that it is set within the range of fluctuation.

When the first phase load is connected to the first phase power line in order to diagnose the first current detection unit, the load fluctuation mainly due to the first phase load occurs in the first phase power line. On the other hand, in the second phase power line, load fluctuation occurs due to the third load. Here, as described above, when the absolute value of the load fluctuation in the second phase power line is less than the second load fluctuation determination value, the first current detection unit is diagnosed. According to this feature configuration, when the absolute value of the load fluctuation in the second phase power line is less than the second load fluctuation judgment value, the absolute value of the load fluctuation due to the third load in the second phase power line is the power consumption of the first phase load. It is less than the load fluctuation due to. In this case, the absolute value of the load fluctuation due to the first phase load generated in the first phase power line becomes larger than the absolute value of the load fluctuation caused by the third load generated in the second phase power line. Therefore, the behavior of the load fluctuation due to the first phase load of the first phase power line and the behavior of the load fluctuation due to the third load of the second phase power line are different, and the first phase power line and the second phase power line can be distinguished. .. Then, it is possible to easily diagnose whether or not the first current detection unit is normal depending on whether or not the first current detection unit detects a large load fluctuation in the first phase power line.

Similarly, when the second phase load is connected to the second phase power line in order to diagnose the second current detection unit, the load fluctuation of the second phase power line mainly occurs due to the second phase load. On the other hand, in the first phase power line, load fluctuation occurs due to the third load. Here, as described above, when the absolute value of the load fluctuation in the first phase power line is less than the first load fluctuation determination value, the second current detection unit is diagnosed. According to this feature configuration, when the absolute value of the load fluctuation in the first phase power line is less than the first load fluctuation determination value, the absolute value of the load fluctuation due to the third load in the first phase power line is the power consumption of the second phase load. It is less than the load fluctuation due to. In this case, the absolute value of the load fluctuation due to the second phase load generated in the second phase power line becomes larger than the absolute value of the load fluctuation caused by the third load generated in the first phase power line. Therefore, the behavior of the load fluctuation of the first phase power line and the behavior of the load fluctuation of the second phase power line are different, and the first phase power line and the second phase power line can be distinguished. Then, it is possible to easily diagnose whether or not the second current detection unit is normal depending on whether or not the second current detection unit detects a large load fluctuation in the second phase power line.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic approval / disapproval determination unit
When the second load fluctuation determination condition is not satisfied, it is determined whether or not the absolute value of the load fluctuation in the first phase power line satisfies the first load fluctuation determination condition, and the current value by the second current detection unit is determined. Determine if detection is possible,
On the other hand, when the first load fluctuation determination condition is not satisfied, it is determined whether or not the absolute value of the load fluctuation in the second phase power line satisfies the second load fluctuation determination condition, and the first current detection unit determines. The point is to determine whether or not the current value can be detected.

According to the above feature configuration, when the second load fluctuation determination condition is not satisfied, that is, when the current value for diagnosing the first current detection unit cannot be detected, the absolute value of the load fluctuation in the first phase power line is It is determined whether or not the first load fluctuation determination condition is satisfied. As a result, the current value for diagnosing the first current detection unit is changed to the current value for diagnosing the second current detection unit according to the load fluctuation status in the first phase power line and the second phase power line. It is possible to respond flexibly to detection. The same applies to the opposite case, and when the first load fluctuation determination condition is not satisfied, that is, when the current value for diagnosing the second current detection unit cannot be detected, the first current detection unit is diagnosed. It is possible to flexibly respond to the detection of the current value.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic approval / disapproval determination unit
When the first load fluctuation determination condition is not satisfied, the first load fluctuation determination value is extended within the range of load fluctuation due to the power consumption of the second phase load.
On the other hand, when the second load fluctuation determination condition is not satisfied, the second load fluctuation determination value is extended within the range of the load fluctuation due to the power consumption of the first phase load.

When the first load fluctuation judgment condition is not satisfied, that is, when the absolute value of the load fluctuation in the first phase power line is equal to or more than the first load fluctuation judgment value, it is impossible to detect the current value for diagnosing the second current detection unit. Become. For example, when the absolute value of the load fluctuation in the first phase power line is large and the possibility that the load fluctuation is less than the first load fluctuation determination value is low, the current value for diagnosing the second current detection unit cannot be detected. It will continue. According to the above feature configuration, when the first load fluctuation determination condition is not satisfied, the first load fluctuation determination value is expanded so that the width of the load fluctuation becomes large. As a result, the current value required for the diagnosis of the second current detection unit can be detected so that the absolute value of the load fluctuation in the first phase power line becomes less than the first load fluctuation determination value. Therefore, it is possible to prevent the state in which the second current detection unit cannot be diagnosed from continuing. Note that extension means changing the setting so that the value becomes larger than the original value, and the same applies to the following.

Similarly, when the second load fluctuation determination condition is not satisfied, the second load fluctuation determination value is expanded so that the width of the load fluctuation becomes large. As a result, the current value required for the diagnosis of the first current detection unit can be detected so that the absolute value of the load fluctuation in the second phase power line becomes less than the second load fluctuation determination value. Therefore, it is possible to prevent the state in which the first current detection unit cannot be diagnosed from continuing.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
When the diagnostic availability determination unit determines that the current value cannot be detected by the current detection unit because the load fluctuation determination condition is not satisfied, the system power supply notifies the third load to suppress the supply of electric power. The point is that it is equipped with a notification unit.

When the current value detection process is not possible as in the above-mentioned characteristic configuration, a notification is given to suppress the supply of power from the system power supply to the third load. When the user of the third load who receives the notification refrains from using the third load, the load fluctuation due to the third load can be suppressed. As a result, the absolute value of the load fluctuation in the power line tends to be less than the predetermined load fluctuation determination value, and the current value can be detected by the first current detection unit and the second current detection unit.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
When the diagnosis possibility determination unit determines that the current value can be detected by the first current detection unit, the first phase load is connected to the first phase power line to receive power from the system power supply. The second phase load is controlled to the first phase load state in which the second phase load is disconnected from the second phase power line, while the current value by the second current detection unit is controlled by the diagnosis possibility determination unit. When it is determined that the first phase load can be detected, the second phase load is connected to the second phase power line so that power from the system power supply can be received, and the first phase load is the first phase load. A phase load control unit that controls the first-phase power line and the second-phase load state, which is a disconnected state,
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic unit for diagnosing whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition. is there.

According to the above characteristic configuration, since the first current detection unit is diagnosed when the load fluctuation in the second phase power line satisfies the second load fluctuation determination condition, the influence of the load fluctuation due to the third load is suppressed. 1 The current detection unit can be diagnosed.
Similarly, in order to diagnose the second current detector when the load fluctuation in the first phase power line satisfies the first load fluctuation determination condition, the second current detector is in a state where the influence of the load fluctuation due to the third load is suppressed. Can be diagnosed.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic approval / disapproval determination unit
When the load fluctuation determination condition is not satisfied, the start-up process necessary for enabling the distributed power generation device to generate power is performed, and the load fluctuation determination condition is set before the distributed power generation device starts power generation. The point is to complete the determination and the determination as to whether or not the current value can be detected.

When the load fluctuation determination condition is not satisfied and the current value cannot be detected as in the above characteristic configuration, further determination of the load fluctuation determination condition and determination of whether or not the current value can be detected are postponed. By first performing the start-up process required to enable power generation by the distributed power generation device, it is possible to prevent the time required for the process including the diagnosis of the current detection unit and various start-up processes from becoming long.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic approval / disapproval determination unit
During power generation by the distributed power generation device, there is a possibility that the maintenance time is approaching and the power generation is stopped, or there is a possibility that the load fluctuation in the power line is smaller than in other time zones and the power generation is stopped. In the case of the timing including, the point is to determine the load fluctuation determination condition and determine whether or not the current value can be detected in the idling state.

If the maintenance time is approaching and there is a possibility that power generation will be stopped, or if the load fluctuation on the power line is less than at other times and there is a possibility that power generation will be stopped, put the distributed power generation device in the idling state. Set. The idling state is either a state in which the distributed power generation device does not output generated power or a state in which the distributed power generation device does not generate power. In such an idling state, it can be estimated that the demand for the power generated by the distributed power generation device is decreasing, and the use of the load in the facility is decreasing. Therefore, although a third load is connected to the power line as a load in the facility, the absolute value of the load fluctuation due to the third load on the power line tends to be less than the load fluctuation determination value in the idling state. Therefore, it is highly preferable that the current value can be detected by determining whether or not the current value can be detected by the current detection unit when the idling state is reached as in the above-mentioned feature configuration.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic approval / disapproval determination unit
When the distributed power generation device is stopped during power generation by the distributed power generation device, it is possible to determine the load fluctuation determination condition and detect the current value within a predetermined time after the start of the stop processing. The point is to decide whether or not.

The outage process is often performed when regular maintenance and cycle outages are scheduled, and it can be estimated that the demand for the power generated by the distributed power generator is declining and the use of the load in the facility is decreasing. .. It can be estimated that the same state is obtained within a predetermined time after the start of the stop processing of the distributed power generation device. Therefore, the third load is connected to the power line as the load in the facility, but if it is within a predetermined time from the start of the stop processing, the absolute value of the load fluctuation due to the third load on the power line becomes less than the load fluctuation judgment value. easy. Therefore, it is highly preferable that the current value can be detected by determining whether or not the current value can be detected by the current detection unit within a predetermined time from the start of the stop processing.

The characteristic configuration of the distributed power generation system according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first phase. A load including a first phase load and a third load which is optionally connected to the first phase power line and the second phase power line and is a load different from the first phase load and the second phase load.
With the above diagnostic equipment
It is in the point of having.

The characteristic configuration of the diagnostic method according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic method for diagnosing whether the current detector is normal or not.
It is determined whether or not the load fluctuation determination condition in which the absolute value of the load fluctuation in the power line is less than the predetermined load fluctuation determination value is satisfied, and when the load fluctuation determination condition is satisfied, the current detection unit performs the current detection unit. The point is that it includes a step of determining that it is possible to detect the current value for diagnosing whether or not the is normal.

The characteristic configuration of the diagnostic apparatus according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic device that diagnoses whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control unit that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic unit that diagnoses whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
When the first diagnostic condition is not satisfied in the first phase load state, the phase load control unit switches to the second phase load state, and the diagnostic unit switches to the second phase load state after switching. Based on whether or not the diagnostic conditions are satisfied, it is diagnosed whether or not the second current detection unit is normal, and
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the phase load control unit switches to the first phase load state, and the diagnostic unit switches to the first phase load state after switching. 1 The point is to diagnose whether or not the first current detection unit is normal based on whether or not the diagnostic conditions are satisfied.

When diagnosing whether or not the first current detector is normal, the first phase load is connected to the first phase power line, and the second phase load is not connected to the second phase power line (first phase load state). .. On the other hand, when diagnosing whether or not the second current detector is normal, the second phase load is connected to the second phase power line, and the first phase load is not connected to the first phase power line (second phase load). Status). The first phase load and the second phase load are loads that consume surplus power generated by, for example, a distributed power generation device.
At this time, a third load is arbitrarily connected to the first phase power line and the second phase power line. The third load is various electric devices such as a television, a refrigerator, and a washing machine. Here, in the following, it is assumed that the third load is connected to each of the first phase power line and the second phase power line.

According to the above characteristic configuration, in the first phase load state, the first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values is generated. If the first diagnostic condition is not satisfied, the phase 2 load state is switched to diagnose whether or not the second diagnostic condition is satisfied. On the contrary, in the second phase load state, the first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values is the second diagnostic condition. If is not satisfied, the phase 2 load state is switched to and it is diagnosed whether or not the first diagnostic condition is satisfied. As a result, the diagnosis of the first current detection unit is changed to the diagnosis of the second flow detection unit, and the diagnosis of the second current detection unit is changed to the first diagnosis according to the load fluctuation status in the first phase power line and the second phase power line. It is possible to respond flexibly, such as changing the diagnosis of the flow detection unit.

The characteristic configuration of the diagnostic apparatus according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic device that diagnoses whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control unit that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic unit that diagnoses whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
The diagnostic unit
When the first diagnostic condition is not satisfied in the first phase load state, the first diagnostic condition is extended within the range of load fluctuation due to the power consumption of the first phase load.
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the second diagnostic condition is extended within the range of load fluctuation due to the power consumption of the second phase load.

According to the above feature configuration, when the first diagnostic condition is not satisfied, the first diagnostic condition is extended so that the range of load fluctuation becomes large. As a result, it is possible to prevent the situation in which the first diagnostic condition is not satisfied from continuing. As a result, it is possible to prevent the situation in which power generation by the distributed power generation device cannot be continued continues.
Similarly, when the second diagnostic condition is not satisfied, the second diagnostic condition is extended so that the range of load fluctuation becomes large. As a result, it is possible to prevent the situation where the second diagnostic condition is not satisfied and the situation where the distributed power generation device cannot generate power continue.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The first diagnostic condition is set based on the load fluctuation due to the power consumed by the first phase load, and the second diagnostic condition is set based on the load fluctuation due to the power consumed by the second phase load. There is a point.

When diagnosing the first current detection unit, the first phase load and the third load are connected to the first phase power line (first phase load state). On the other hand, when diagnosing the second current detection unit, the second phase load and the third load are connected to the second phase power line (second phase load state). Therefore, when the 1st phase load and the 3rd phase load are connected to the 1st phase power line, the load fluctuation due to the 1st phase load and the 3rd load consuming the power from the system power supply is generated in the 1st phase power line. Occurs. Further, when the second phase load and the third load are connected to the second phase power line, the second phase power line is subjected to load fluctuation due to the second phase load and the third load consuming the power from the system power supply. Occurs.

When diagnosing whether or not the current detection unit is normal, it is necessary to be able to grasp whether or not the load fluctuation when the first phase load is connected to the first phase power line is generated in the first phase power line. If a large load fluctuation occurs in the first phase power line when the first phase load is connected to the first phase power line, and a large load fluctuation also occurs in the second phase power line, the first phase power line and the first phase power line It is not possible to ascertain whether or not the load fluctuation of any of the second phase power lines is caused by connecting the first phase load to the first phase power line.

Here, when the first phase load is connected to the first phase power line in order to diagnose the first current detection unit, the load fluctuation due to the first phase load occurs in the first phase power line. On the other hand, in the second phase power line, load fluctuation occurs due to the third load. When the first phase load is larger than the third load, the absolute value of the load fluctuation due to the first phase load generated in the first phase power line is larger than the absolute value of the load fluctuation caused by the third load generated in the second phase power line. growing. According to this feature configuration, the first diagnostic condition for diagnosing the first current detection unit is set based on the load fluctuation due to the first phase load. In this case, it is possible to distinguish between the behavior of the load fluctuation due to the first phase load of the first phase power line and the behavior of the load fluctuation due to the third load of the second phase power line based on the load fluctuation due to the first phase load. Then, it is possible to easily diagnose whether or not the first current detection unit is normal depending on whether or not the first current detection unit detects a large load fluctuation in the first phase power line.

Similarly, when the second phase load is connected to the second phase power line in order to diagnose the second current detection unit, the load fluctuation due to the second phase load occurs in the second phase power line. On the other hand, in the first phase power line, load fluctuation occurs due to the third load. When the second phase load is larger than the third load, the absolute value of the load fluctuation due to the second phase load generated in the second phase power line is larger than the absolute value of the load fluctuation caused by the third load generated in the first phase power line. growing. According to this feature configuration, the second diagnostic condition for diagnosing the second current detection unit is set based on the load fluctuation due to the second phase load. In this case, it is possible to distinguish between the behavior of the load fluctuation due to the second phase load of the second phase power line and the behavior of the load fluctuation due to the third load of the first phase power line based on the load fluctuation due to the second phase load. Then, it is possible to easily diagnose whether or not the second current detection unit is normal depending on whether or not the second current detection unit detects a large load fluctuation in the second phase power line.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
At least one of the cases where the diagnostic unit determines that the first diagnostic condition is not satisfied in the first phase load state and the case where the second diagnostic condition is not satisfied in the second phase load state. In this case, a notification unit for notifying the supply of electric power from the system power supply to the third load is provided.

When the current detection unit is diagnosed as abnormal as in the above-mentioned characteristic configuration, it is notified to suppress the supply of power from the system power supply to the third load. When the user of the third load who receives the notification refrains from using the third load, the load fluctuation due to the third load can be suppressed. As a result, the first current detection unit and the second current detection unit can be diagnosed while the load fluctuation due to the third load is suppressed.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic unit
When at least one of the first diagnostic condition and the second diagnostic condition is not satisfied, the start-up process necessary for enabling power generation by the distributed power generation device is performed, and the distributed power generation device generates power. The point is to complete the determination of the first diagnostic condition and the second diagnostic condition before starting.

If at least one of the first diagnostic condition and the second diagnostic condition is not satisfied as in the above characteristic configuration, the diagnosis of the current detection unit is postponed. By first performing the start-up process required to enable power generation by the distributed power generation device, it is possible to prevent the time required for the process including the diagnosis of the current detection unit and various start-up processes from becoming long.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic unit
When there is a possibility that the maintenance time is approaching and the power generation is stopped during the power generation by the distributed power generation device, or when the load fluctuation in the power line is less than in other time zones and the power generation may be stopped. In the case of the timing including, the first diagnostic condition is determined and the second diagnostic condition is determined in the idling state.

If the maintenance time is approaching and there is a possibility that power generation will be stopped, or if the load fluctuation on the power line is less than at other times and there is a possibility that power generation will be stopped, put the distributed power generation device in the idling state. Set. The idling state is either a state in which the distributed power generation device does not output generated power or a state in which the distributed power generation device does not generate power. In such an idling state, it can be estimated that the demand for the power generated by the distributed power generation device is decreasing, and the use of the load in the facility is decreasing. Therefore, although a third load is connected to the power line as a load in the facility, the absolute value of the load fluctuation due to the third load on the power line tends to be small in the idling state. Therefore, the current detection unit can be efficiently diagnosed in the idling state.

Further characteristic configurations of the diagnostic apparatus according to the present invention are:
The diagnostic unit
When the distributed power generation device is stopped during power generation by the distributed power generation device, the determination of the first diagnostic condition and the determination of the second diagnostic condition and the second diagnostic condition are performed within a predetermined time after the start of the stop processing. The point is to make a judgment.

The outage process is often performed when regular maintenance and cycle outages are scheduled, and it can be estimated that the demand for the power generated by the distributed power generator is declining and the use of the load in the facility is decreasing. .. It can be estimated that the same state is obtained within a predetermined time after the start of the stop processing of the distributed power generation device. Therefore, the third load is connected to the power line as the load in the facility, but if it is within a predetermined time from the start of the stop processing, the absolute value of the load fluctuation due to the third load on the power line becomes less than the load fluctuation judgment value. easy. Therefore, the current detection unit can be efficiently diagnosed within a predetermined time from the start of the stop processing.

The characteristic configuration of the distributed power generation system according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first phase. A load including a first phase load and a third load which is optionally connected to the first phase power line and the second phase power line and is a load different from the first phase load and the second phase load.
With the above diagnostic equipment
It is in the point of having.

The characteristic configuration of the diagnostic method according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic method for diagnosing whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control step that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic step for diagnosing whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
When the first diagnostic condition is not satisfied in the first phase load state, the phase load control step switches to the second phase load state, and in the diagnostic step, the second phase load state after switching is performed. Based on whether or not the diagnostic conditions are satisfied, it is diagnosed whether or not the second current detection unit is normal, and
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the phase is switched to the first phase load state in the phase load control step, and in the diagnostic step, the first phase load state after the switching is performed. 1 The point is to diagnose whether or not the first current detection unit is normal based on whether or not the diagnostic conditions are satisfied.

The characteristic configuration of the diagnostic method according to the present invention is
A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic method for diagnosing whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control step that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic step for diagnosing whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
In the diagnostic step
When the first diagnostic condition is not satisfied in the first phase load state, the first diagnostic condition is extended within the range of load fluctuation due to the power consumption of the first phase load.
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the second diagnostic condition is extended within the range of load fluctuation due to the power consumption of the second phase load.

It is an overall block diagram of a distributed power generation system. This is an example of load fluctuation judgment conditions. This is an example of CT diagnostic conditions. It is a flowchart of 1st CT diagnosis processing. It is a flowchart of the preliminary judgment processing. It is a flowchart of the pre-judgment process which accompanies the change of the load judgment condition. This is an example of the load fluctuation judgment condition after expansion. It is a flowchart of the 2nd CT diagnosis processing. It is a flowchart of the 2nd CT diagnosis processing which accompanies the change of CT diagnosis condition. This is an example of CT diagnostic conditions after expansion. It is a flowchart of the 2nd CT diagnosis processing. It is a flowchart of the 2nd CT diagnosis processing which accompanies the change of CT diagnosis condition. It is a flowchart which shows the timing to execute CT diagnosis processing. It is a flowchart which shows the timing to execute CT diagnosis processing. It is a flowchart which shows the timing to execute CT diagnosis processing. It is a flowchart which shows the timing to execute CT diagnosis processing. It is a schematic diagram of the time-dependent change of load fluctuation.

As a method for improving the diagnosis of the current detection unit, in the first embodiment, the case where the load fluctuation in the power line is small is determined in advance (hereinafter, may be referred to as the pre-determination process), and the current when the load fluctuation is small. A process for diagnosing the detection unit (hereinafter, may be referred to as a CT (Current Trans) diagnostic process) is performed. The load fluctuation is a fluctuation of the electric power caused by the load connected to the power line consuming the electric power supplied to the power line.
Further, as a method for improving the diagnosis of the current detection unit, in the second embodiment, a process of changing the flow of the CT diagnosis process at any time, a process of changing the CT diagnosis condition for the CT diagnosis process, and the like are performed.
The first and second embodiments will be described below.

[First Embodiment]
Hereinafter, the diagnostic device according to the first embodiment and the distributed power generation system including the diagnostic device will be described with reference to FIG.
(1) Overall Configuration As shown in FIG. 1, the distributed power generation system 100 is connected to the system power supply 10, and includes a main breaker 11, a power conversion device 13, and a distributed power generation device 15. The system power supply 10, the main breaker 11, the power conversion device 13, and the distributed power generation device 15 are connected via a single-phase three-wire power line 21. A power load (an example of a third load) 35 and an electric heater 48 in the facility, which will be described later, are connected to the power line 21. Further, the distributed power generation system 100 includes a control unit 50 (including a diagnostic device) that performs CT diagnosis processing of the current detection unit 17 described later, operation control of the distributed power generation device 15, and the like.

(1-1) System power supply The system power supply 10 is, for example, a single-phase three-wire system 100V / 200V, and the wiring from the system power supply 10 is composed of three power lines 21. The power line 21 includes a U-phase power line (an example of a first-phase power line) 21U, a W-phase power line (an example of a second-phase power line) 21W, and a neutral line 21N. There is a potential difference of 100V between the U-phase power line 21U and the neutral line 21N, there is a potential difference of 100V between the W-phase power line 21W and the neutral line 21N, and there is a potential difference of 100V between the U-phase power line 21U and the W-phase power line 21W. Has a potential difference of 200V.

(1-2) Distributed power generation device, power conversion device The distributed power generation device 15 is, for example, a power generation device such as a fuel cell or a solar power generation device. When the distributed power generation device 15 is a fuel cell, the fuel gas (for example, city gas 13A) and the oxidant gas are reacted to generate electricity. When the distributed power generation device 15 is a fuel cell, the distributed power generation device 15 is provided with a heat exchanger that recovers heat, a hot water storage tank that stores water heated by the heat exchange, and the like.

The distributed power generation device 15 and the system power supply 10 are connected to each other via the power conversion device 13. The power conversion device 13 converts the generated power generated by the distributed power generation device 15 into the same voltage and frequency as the grid power source 10, and connects the generated power generated by the distributed power generation device 15 to the grid power source 10. ..

Further, the power line 21 is provided with a switch 12 for connecting and disconnecting the distributed power generation device 15 and the system power supply 10. Switches 12U, 12N, and 12W are provided for each of the U-phase power line 21U, the neutral line 21N, and the W-phase power line 21W, respectively. The switches 12U, 12N, and 12W are opened when system power is not supplied from the system power source 10 due to, for example, a power failure, and the distributed power generation device 15 and the system power source 10 are electrically disconnected. The switches 12U, 12N, and 12W are provided, for example, between the contacts of the in-facility power load (an example of the third load) 35 and the power line 21 described later and the contacts of the electric heater 48 and the power line 21 described later.

(1-3) Main breaker In the main breaker 11 that functions as a power breaker, for example, elements (not shown) corresponding to each of the U-phase power line 21U, the W-phase power line 21W, and the neutral line 21N are arranged. .. When a current exceeding the rated current (for example, 50A) flows through each of the power lines 21, the element is disconnected and the electrical connection with the system power supply 10 is cut off.

(1-4) Current detection unit The U-phase power line (an example of the first-phase power line) 21U and the W-phase power line (an example of the second-phase power line) 21W are the current detection units for detecting the current value in each power line. 17 is provided. A U-phase current detection unit (an example of a first current detection unit) 17U is attached to the U-phase power line 21U between the distributed power generation device 15 and the system power supply 10. The U-phase current detection unit 17U detects the current value (U) flowing through the U-phase power line 21U. On the other hand, a W-phase current detection unit (an example of a second current detection unit) 17W is attached to the W-phase power line 21W between the distributed power generation device 15 and the system power supply 10. The W-phase current detection unit 17W detects the current value (W) flowing through the W-phase power line 21W.

Since such a current detection unit 17 needs to be normal, that is, the current detection unit 17 needs to be able to accurately detect the current value in the desired power line 21, CT diagnosis processing is performed. The CT diagnosis process in the present embodiment is mainly performed depending on whether or not the load fluctuation according to the current value detected by the current detection unit 17 satisfies a predetermined CT diagnosis condition. The CT diagnostic process of this embodiment will be described later.
The current detection unit 17 is normal when a predetermined CT diagnostic condition is satisfied. In addition, the current detection unit 17 means that the current detection unit 17 is normal, that the current detection unit 17 is attached to a predetermined power line without a connection failure, that the current detection unit 17 can detect the current value to be detected, and other abnormalities in the connection state. It may include a state in which there is almost no abnormality in the detection accuracy of the current or the current.

(1-5) In-facility power load The U-phase power line 21U and the W-phase power line 21W are connected to the in-facility power load (an example of the third load) 35 via the first and second branch cables 31, 32 and the branch breaker 33. Is connected. In the present embodiment, the first U-phase branch cable 31U is connected to the U-phase power line 21U, and the first neutral branch cable 31N is connected to the neutral line 21N. The first branch breaker 33a is connected between the U phase power line 21U and the neutral line 21N via the first U phase branch cable 31U and the first neutral branch cable 31N, and the secondary side of the first branch breaker 33a. The power load 35a in the first facility is connected to. On the other hand, the second W phase branch cable 32W is connected to the W phase power line 21W, and the second neutral branch cable 32N is connected to the neutral line 21N. A second branch breaker 33b is connected between the W phase power line 21W and the neutral line 21N via the second W phase branch cable 32W and the second neutral branch cable 32N, and the secondary side of the second branch breaker 33b is connected. The power load 35b in the second facility is connected to the second facility.

The in-facility power load 35 including the first in-facility power load 35a and the second in-facility power load 35b is various electric devices installed in the facility, such as a television, a refrigerator, and a washing machine. The in-facility power load 35 can be supplied with power from at least one of the system power from the system power source 10 and the power generated from the distributed power generation device 15.

(1-6) Electric heater An example of an electric heater (phase load (first phase load, second phase load)) is provided to the U-phase power line 21U and the W-phase power line 21W via the first and second branch cables 41 and 42. ) 48 is connected. In the present embodiment, the first U-phase branch cable 41U is connected to the U-phase power line 21U, and the first neutral branch cable 41N is connected to the neutral line 21N. The first U phase branch cable 41U is connected to one end of a first electric heater (an example of a first phase load) 48U via a first U phase switch 43U. Further, the first neutral branch cable 41N is connected to the other end of the first electric heater 48U via the first neutral switch 43N. On the other hand, the second W phase branch cable 42W is connected to the W phase power line 21W, and the second neutral branch cable 42N is connected to the neutral line 21N. The second W phase branch cable 42W is connected to one end of a second electric heater (an example of a second phase load) 48W via a second W phase switch 44W. Further, the second neutral branch cable 42N is connected to the other end of the second electric heater 48W via the second neutral switch 44N.

By closing the first U-phase switch 43U and the first neutral switch 43N, the first electric heater 48U is electrically connected between the U-phase power line 21U and the neutral line 21N. On the other hand, when the second W phase switch 44W and the second neutral switch 44N are closed, the second electric heater 48W is electrically connected between the U phase power line 21U and the neutral line 21N.

The electric heater 48 can consume at least one of the grid power of the grid power source 10 and the generated power of the distributed power generation device 15. When surplus power is generated in the generated power of the distributed power generation device 15, that is, when the generated power is larger than the power consumed by the power load 35 in the facility, the surplus power can be consumed by the electric heater 48. This makes it possible to prevent reverse power flow in which the generated power is supplied to the system power supply 10. Further, the heat generated by the electric heater 48 can be used to heat the water in the hot water storage tank.
In the present embodiment, the power consumption of the first electric heater 48U and the second electric heater 48W is set to about 500W, respectively.

(1-7) Control unit The control unit 50 includes a heater control unit (an example of a phase load control unit) 51 that controls the connection between the first electric heater 48U and the second electric heater 48W and the power line 21, and a current detection unit 17. Diagnose whether or not the current detection unit 17 is normal, the diagnostic availability determination unit 53 that determines whether or not the current value can be detected, the notification unit 55 that performs predetermined notification based on the control of the diagnosis availability determination unit 53, and the current detection unit 17. Diagnostic unit 57, a storage unit 58 that stores various data such as load fluctuation determination conditions for determining the magnitude of load fluctuation on the power line 21, and CT diagnostic conditions used for CT diagnostic processing, and a distributed power generation device. It is provided with a power generation control unit 59 that performs various operation controls and the like. The diagnostic availability determination unit 53 is included in a diagnostic device for diagnosing whether or not the current detection unit 17 is normal. The diagnostic device may also include at least one of a heater control unit 51, a notification unit 55, a diagnostic unit 57, and a storage unit 58.

(A) Storage unit (a1) Load fluctuation determination condition The storage unit 58 stores the load fluctuation determination condition for determining the magnitude of the load fluctuation on the power line 21. As shown in FIG. 2, in the present embodiment, the U-phase side load fluctuation determination value Xu (an example of the first load fluctuation determination value) and the W-phase side load fluctuation determination value Xw (second load variation) are used as load fluctuation determination conditions. An example of the judgment value) is prepared. The U-phase side load fluctuation determination value Xu is a determination value for determining the magnitude of the load variation on the U-phase power line 21U. The W-phase side load fluctuation determination value Xw is a determination value for determining the magnitude of the load variation in the W-phase power line 21W.
In the present embodiment, the value of the load fluctuation is an instantaneous value of the electric power measured by the power line 21 at a certain time point.
Further, here, when the power generated by the distributed power generation device 15 is constant (including the case where power generation is stopped) and the power consumption of the electric heater 48 is constant, the current value is detected by the current detection unit 17. Will be done. The load fluctuation in the U-phase power line 21U is a load fluctuation (U-phase side load fluctuation) corresponding to the current value (U) detected by the U-phase current detection unit 17U. The load fluctuation in the W-phase power line 21W is a load fluctuation (W-phase side load fluctuation) corresponding to the current value (W) detected by the W-phase current detection unit 17W.
Further, when the U-phase side load fluctuation determination value Xu and the W-phase side load fluctuation determination value Xw are collectively referred to, they are simply referred to as load fluctuation determination values.

Specifically, in FIG. 2, the U-phase side load fluctuation determination value Xu is set to ± 250 W. In this case, when the load fluctuation on the U-phase power line 21U is larger than −250 W and less than 250 W, it means that the load fluctuation on the U-phase power line 21U is small. That is, when the absolute value of the load fluctuation on the U-phase power line 21U is less than 250 W, it means that the load fluctuation on the U-phase power line 21U is small. On the other hand, when the load fluctuation in the U-phase power line 21U is in the range of −250 W or less and the range of 250 W or more, it means that the load fluctuation in the U-phase power line 21U is large. That is, when the absolute value of the load fluctuation on the U-phase power line 21U is 250 W or more, it means that the load fluctuation on the U-phase power line 21U is large.

The same applies to the W-phase side load fluctuation determination value Xw. When the absolute value of the load fluctuation in the W-phase power line 21W is less than 250W, the load fluctuation in the W-phase power line 21W is small, and conversely, when the absolute value of the load fluctuation in the W-phase power line 21W is 250W or more, the W-phase power line This means that the load fluctuation at 21 W is large.

In FIG. 2, the U-phase side load fluctuation determination value Xu and the W-phase side load fluctuation determination value Xw are set to the same ± 250W. However, the U-phase side load fluctuation determination value Xu and the W-phase side load fluctuation determination value Xw may be set to different values.

Further, the U-phase side load fluctuation determination value Xu (± 250W) used for determining whether or not the W-phase current detection unit 17W can be diagnosed is within the range of the load fluctuation (± 500W) due to the power consumed by the second electric heater 48W. It is preferable that it is set in. In this case, the absolute value of the load fluctuation caused by the second electric heater 48W generated in the W-phase power line 21W is larger than the absolute value of the load fluctuation caused by the first facility power load 35a generated in the U-phase power line 21U. Therefore, the behavior of the load fluctuation due to the second electric heater 48W of the W-phase power line 21W and the behavior of the load fluctuation due to the power load 35a in the first facility of the U-phase power line 21U are different, and the U-phase power line 21U and the W-phase power line 21W are separated. Can be distinguished. Then, it is possible to easily diagnose whether or not the W-phase current detection unit 17W is normal depending on whether or not the W-phase current detection unit 17W detects a large load fluctuation in the W-phase power line 21W.

Similarly, the W-phase side load fluctuation determination value Xw (± 250W) used to determine whether or not the U-phase current detection unit 17U can be diagnosed is within the range of the load fluctuation (± 500W) due to the power consumed by the first electric heater 48U. It is preferable that it is set within. In this case, the absolute value of the load fluctuation caused by the first electric heater 48U generated in the U-phase power line 21U is larger than the absolute value of the load fluctuation caused by the second facility power load 35b generated in the W-phase power line 21W. Therefore, the behavior of the load fluctuation due to the first electric heater 48U of the U-phase power line 21U and the behavior of the load fluctuation due to the power load 35b in the second facility of the W-phase power line 21W are different, and the U-phase power line 21U and the W-phase power line 21W are separated. Can be distinguished. Then, it is possible to easily diagnose whether or not the U-phase current detection unit 17U is normal depending on whether or not the U-phase current detection unit 17U detects a large load fluctuation in the U-phase power line 21U.

(A2) CT Diagnosis Condition Further, the storage unit 58 stores the CT diagnosis condition used for the CT diagnosis process for diagnosing whether or not the current detection unit 17 is normal. As shown in FIG. 3, in the present embodiment, the U-phase side CT diagnostic condition Yu (an example of the first diagnostic condition) and the W-phase side CT diagnostic condition Yw (an example of the second diagnostic condition) are prepared as CT diagnostic conditions. Has been done. The U-phase side CT diagnostic condition Yu is a determination value for diagnosing whether or not the U-phase current detection unit 17U is normal. The W-phase side CT diagnostic condition Yw is a determination value for diagnosing whether or not the W-phase current detection unit 17W is normal.

In FIG. 3, specifically, as the U-phase side CT diagnostic condition Yu, the load fluctuation on the U-phase power line 21U (U-phase side load fluctuation in FIG. 3) is set to ± 250 W or more, and the load on the W-phase power line 21 W is set. The fluctuation (W-phase load fluctuation in FIG. 3) is set to less than ± 250W.
Similar to the above, when the power generated by the distributed power generation device 15 is constant (including the case where power generation is stopped) and the power consumption of the electric heater 48 is constant, the current value for CT diagnosis processing is constant. It is detected by the current detection unit 17. The load fluctuation in the U-phase power line 21U is a load fluctuation (U-phase side load fluctuation) corresponding to the current value (U) detected by the U-phase current detection unit 17U. The load fluctuation in the W-phase power line 21W is a load fluctuation (W-phase side load fluctuation) corresponding to the current value (W) detected by the W-phase current detection unit 17W. The U-phase load fluctuation of ± 250 W or more means that the U-phase load fluctuation is in the range of −250 W or less and the range of 250 W or more. Further, when the W-phase side load fluctuation is less than ± 250 W, it means that the W-phase side load fluctuation is in the range of more than −250 W and less than 250 W.
That is, when the absolute value of the load fluctuation (U-phase side load fluctuation) on the U-phase power line 21U is 250 W or more, and the absolute value of the load fluctuation (W-phase side load fluctuation) on the W-phase power line 21 W is less than 250 W. In addition, it is determined that the U-phase current detection unit 17U is normal.
The load fluctuation in each power line 21 is a load fluctuation corresponding to the current value detected by the current detection unit 17.

Further, in FIG. 3, as the W-phase side CT diagnostic condition Yw, the load fluctuation on the U-phase power line 21U (U-phase side load fluctuation in FIG. 3) is set to less than ± 250 W, and the load fluctuation on the W-phase power line 21W is set. (W-phase side load fluctuation in FIG. 3) is set to ± 250 W or more. That is, when the absolute value of the load fluctuation (U-phase side load fluctuation) on the U-phase power line 21U is less than 250 W, and the absolute value of the load fluctuation (W-phase side load fluctuation) on the W-phase power line 21W is 250 W or more. In addition, it is determined that the W-phase current detection unit 17W is normal.

Further, the U-phase side CT diagnostic condition Yu for diagnosing the U-phase current detection unit 17U (the absolute value of the load fluctuation in the U-phase power line 21U is 250 W or more, and the absolute value of the load fluctuation in the W-phase power line 21 W is (Less than 250W) is set based on the load fluctuation (± 500W) caused by the first electric heater 48U. In this case, when the first electric heater 48U is larger than the power load 35b in the second facility, the behavior of the load fluctuation by the first electric heater 48U of the U-phase power line 21U is based on the load fluctuation by the first electric heater 48U. And the behavior of the load fluctuation due to the power load 35b in the second facility of the W phase power line 21W can be distinguished. Then, it is possible to easily diagnose whether or not the U-phase current detection unit 17U is normal depending on whether or not the U-phase current detection unit 17U detects a large load fluctuation in the U-phase power line 21U.

Similarly, the W-phase side CT diagnostic condition Yw for diagnosing the W-phase current detection unit 17W (the absolute value of the load fluctuation on the W-phase power line 21W is 250 W or more, and the absolute value of the load fluctuation on the U-phase power line 21U). Is less than 250W) is set based on the load fluctuation (± 500W) due to the second electric heater 48W. In this case, when the second electric heater 48W is larger than the power load 35a in the first facility, the behavior of the load fluctuation by the second electric heater 48W of the W phase power line 21W is based on the load fluctuation by the second electric heater 48W. And the behavior of the load fluctuation due to the power load 35a in the first facility of the U-phase power line 21U can be distinguished. Then, it is possible to easily diagnose whether or not the W-phase current detection unit 17W is normal depending on whether or not the W-phase current detection unit 17W detects a large load fluctuation in the W-phase power line 21W.

In FIG. 3, the same 250 W is used as a diagnostic criterion in all of the U-phase side load fluctuation and the W-phase side load fluctuation of the U-phase side CT diagnostic condition Yu and the W-phase side CT diagnostic condition Yw. .. However, different diagnostic criteria may be used in each column of FIG.

Further, the judgment reference values of the U-phase side load fluctuation judgment value Xu and the W-phase side load fluctuation judgment value Xw in FIG. 2 are 250W, and the U-phase side CT diagnosis condition Yu and the W-phase side CT diagnosis condition Yw in FIG. 3 The diagnostic reference value is also the same at 250 W. Both the U-phase side load fluctuation determination value Xu and the W-phase side load fluctuation determination value Xw in FIG. 2 and the U-phase side CT diagnostic condition Yu and the W-phase side CT diagnostic condition Yw in FIG. 3 are the first electric heaters on the U-phase side. Since it is determined whether the load fluctuation is large when the 48U is applied to the U-phase power line 21U or the load fluctuation when the second electric heater 48W on the W-phase side is applied to the W-phase power line 21W, it is almost the same. It is preferably set to a value.

(B) Diagnosis possibility determination unit The diagnosis possibility determination unit 53 performs a preliminary determination process as to whether or not the current value can be detected by the current detection unit 17 before diagnosing whether or not the current detection unit 17 is normal. In the pre-determination process, the diagnostic enable / disable determination unit 53 can detect whether or not the current value (U) for diagnosing whether the U-phase current detection unit 17U is normal or not, and whether the W-phase current detection unit 17W is normal or not. It is determined whether or not the current value (W) for diagnosing whether or not it can be detected.

First, when the power generated by the distributed power generation device 15 is constant (including the case where power generation is stopped) and the power consumption of the electric heater 48 is constant, the diagnosis possibility determination unit 53 performs CT diagnosis processing. The load fluctuations in the U-phase power line 21U and the W-phase power line 21W are acquired. Here, the diagnosis possibility determination unit 53 acquires the load fluctuation in the U-phase power line 21U based on the current value (U) acquired by the U-phase current detection unit 17U. Similarly, the diagnostic enable / disable determination unit 53 acquires the load fluctuation in the W-phase power line 21W based on the current value (W) acquired by the W-phase current detection unit 17W.
In addition, the diagnosis possibility determination unit 53 may acquire the load fluctuation of each power line 21U and 21W based on a power meter (not shown) provided for each of the U-phase power line 21U and the W-phase power line 21W.

(B1) Determining whether or not the current value (U) for diagnosing the U-phase current detection unit 17U can be detected The diagnosis-possibility determination unit 53 refers to the load fluctuation determination condition of FIG. It is determined whether or not the absolute value of the fluctuation is less than the W-phase side load fluctuation determination value Xw. That is, the diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the W-phase power line 21W is less than 250W (the load fluctuation in the W-phase power line 21W is larger than −250W and less than 250W). When the absolute value of the load fluctuation in the W-phase power line 21W is less than 250W, the diagnostic availability determination unit 53 detects the current value (U) for diagnosing the U-phase current detection unit 17U by the U-phase current detection unit 17U. Decide that it is possible.
On the other hand, when the absolute value of the load fluctuation in the W-phase power line 21W is 250 W or more, the diagnosis possibility determination unit 53 determines the current value (U) for diagnosing the U-phase current detection unit 17U by the U-phase current detection unit 17U. Is determined to be undetectable.

(B2) Determining whether or not the current value (W) for diagnosing the W-phase current detection unit 17W can be detected The diagnosis-possibility determination unit 53 refers to the load fluctuation determination condition of FIG. It is determined whether or not the absolute value of the fluctuation is less than the U-phase side load fluctuation determination value Xu. That is, the diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the U-phase power line 21U is less than 250 W (the load fluctuation in the U-phase power line 21U is larger than −250 W and less than 250 W). When the absolute value of the load fluctuation in the U-phase power line 21U is less than 250 W, the diagnostic availability determination unit 53 detects the current value (W) for diagnosing the W-phase current detection unit 17W by the W-phase current detection unit 17W. Decide that it is possible.
On the other hand, when the absolute value of the load fluctuation in the U-phase power line 21U is 250 W or more, the diagnosis possibility determination unit 53 uses the W-phase current detection unit 17W to diagnose the W-phase current detection unit 17W (W). Is determined to be undetectable.

The current detection unit 17 is diagnosed when the absolute value of the load fluctuation in the power line 21 is less than the load fluctuation determination value, that is, when the absolute value of the load fluctuation due to the in-facility power load 35 connected to the power line 21 is small. It is determined that the current value for this can be obtained. As a result, when the first electric heater (U-phase load) 48U is connected to the U-phase power line 21U in order to diagnose the current detection unit 17, a large load fluctuation occurs in the U-phase power line 21U, but the connection is made to the W-phase power line 21W. It is possible to prevent the power load 35b in the second facility from being applied from giving a large load fluctuation to the W-phase power line 21W.
Similarly, when the second electric heater (W phase load) 48W is connected to the W phase power line 21W for diagnosing the current detection unit 17, a large load fluctuation occurs in the W phase power line 21W, but it is connected to the U phase power line 21U. It is possible to prevent the power load 35a in the first facility from being applied from giving a large load fluctuation to the U-phase power line 21U. As a result, the influence of the load fluctuation of the power load 35 in the facility on the power line 21 can be suppressed, and the erroneous diagnosis as to whether or not the current detection unit 17 is normal can be suppressed.

In particular, regular maintenance is performed after the operation of the distributed power generation device 15 is started, and it is assumed that the power load 35 in the facility installed in the facility is operating during the regular maintenance. In the above embodiment, even after the operation of the power load 35 in the facility is started, a time zone in which the load fluctuation of the power line 21 is small is extracted, and the current detection unit 17 is diagnosed in the time zone. .. Therefore, the current detection unit 17 can be diagnosed while suppressing the influence of the load fluctuation due to the power load 35 in the facility.

(C) Heater control unit The heater control unit 51 diagnoses the U-phase current detection unit 17U when the diagnosis availability determination unit 53 determines that the current value (U) can be detected by the U-phase current detection unit 17U. Therefore, the connection state of the load to the power line 21 is set to the U-phase load state (an example of the first-phase load state). In the U-phase load state, the first electric heater (U-phase load) 48U is connected to the U-phase power line 21U so that power from the system power supply 10 can be received, and the second electric heater (W-phase load). 48W is in a state of being disconnected from the W-phase power line 21W.

Specifically, in the U-phase load state, the first U-phase switch 43U and the first neutral switch 43N are closed, and the first electric heater 48U is connected to the U-phase power line 21U and the neutral line 21N to supply the system power supply 10. It is controlled so that it can receive the grid power from. Further, the second W phase switch 44W and the second neutral switch 44N are opened, and the second electric heater 48W is controlled in a state of being disconnected from the W phase power line 21W and the neutral line 21N. Further, the in-facility power load 35 is arbitrarily connected to either the U-phase power line 21U or the W-phase power line 21W, and is connected to the neutral line 21N so that the system power from the system power source 10 can be received. It has become.

In the U-phase load state and the W-phase load state described later, the power load 35 in the facility is arbitrarily connected to the power line 21. In the present embodiment, the first facility power load 35a is connected to the U-phase power line 21U and the neutral line 21N, and the second facility power load 35b is connected to the W-phase power line 21W and the neutral line 21N. ..

Therefore, in the U-phase load state, the first electric heater 48U and the power load 35a in the first facility are connected to the U-phase power line 21U, and the load fluctuation due to the first electric heater 48U and the power load 35a in the first facility. Occurs. Further, in the U-phase load state, the power load 35b in the second facility is connected to the W-phase power line 21W, and the load fluctuates due to the power load 35b in the second facility.

Further, when the heater control unit 51 determines that the W-phase current detection unit 17W can detect the current value (W) by the diagnosis availability determination unit 53, the heater control unit 51 diagnoses the W-phase current detection unit 17W. The connection state of the load to the power line 21 is set to the W phase load state (an example of the second phase load state). In the W-phase load state, the second electric heater (W-phase load) 48W is connected to the W-phase power line 21W and can receive power from the system power supply 10, and the first electric heater (U-phase load). 48U is in a state of being disconnected from the U-phase power line 21U.

Specifically, in the W phase load state, the second W phase switch 44W and the second neutral switch 44N are closed, and the second electric heater 48W is connected to the W phase power line 21W and the neutral line 21N to supply the system power supply 10. It is controlled so that it can receive the grid power from. Further, the first U-phase switch 43U and the first neutral switch 43N are opened, and the first electric heater 48U is controlled in a state of being disconnected from the U-phase power line 21U and the neutral line 21N. Further, the power load 35a in the first facility is connected to the U-phase power line 21U and the neutral line 21N, and the power load 35b in the second facility is connected to the W-phase power line 21W and the neutral line 21N.

Therefore, in the W-phase load state, the second electric heater 48W and the power load 35b in the second facility are connected to the W-phase power line 21W, and the load fluctuation due to the second electric heater 48W and the power load 35b in the second facility. Occurs. Further, in the W-phase load state, the power load 35a in the first facility is connected to the U-phase power line 21U, and the load fluctuates due to the power load 35a in the first facility.

The heater control unit 51 connects the first electric heater 48U and the second electric heater 48W to the U-phase power line 21U and the W-phase power line 21W even when the distributed power generation device 15 consumes the surplus power generated. Can be controlled.

(D) It is assumed that the notification unit diagnosis availability determination unit 53 determines that the current value cannot be detected by at least one of the U-phase current detection unit 17U and the W-phase current detection unit 17W. The notification unit 55 receives a command from the diagnosis availability determination unit 53 to notify that the use of the power load 35 in the facility is to be withheld, and executes the command. The notification unit 55 is not particularly limited, but is a device capable of transmitting sound, an image, or the like.

When the user of the facility power load 35 who has received the notification refrains from using the facility power load 35, the load fluctuation due to the facility power load 35 can be suppressed. As a result, the U-phase current detection unit 17U and the W-phase current detection unit 17W can be diagnosed while the load fluctuation due to the power load 35 in the facility is suppressed.

(E) Diagnosis unit The diagnosis unit 57 diagnoses whether or not the U-phase current detection unit 17U is normal and whether or not the W-phase current detection unit 17W is normal with reference to the CT diagnostic conditions of FIG. As described above, when it is determined by the diagnostic availability determination unit 53 that the current value (U) can be detected by the U-phase current detection unit 17U, the U-phase load state is set to diagnose the U-phase current detection unit 17U. Set. Further, when the diagnosis possibility determination unit 53 determines that the current value (W) can be detected by the W phase current detection unit 17W, the W phase load state is set to diagnose the W phase current detection unit 17W. To.

First, a case of diagnosing whether or not the U-phase current detection unit 17U is normal will be described.
When the diagnostic unit 57 is in a U-phase load state in which the first electric heater 48U is connected to the U-phase power line 21U, the load fluctuation in the U-phase power line 21U and the load fluctuation in the W-phase power line 21W are the U-phase shown in FIG. It is determined whether or not the side CT diagnostic condition Yu is satisfied.
Here, the load fluctuation in the U-phase power line 21U is a load fluctuation obtained corresponding to the current value (U) detected by the U-phase current detection unit 17U. Further, the load fluctuation in the W-phase power line 21W is a load fluctuation obtained corresponding to the current value (W) detected by the W-phase current detection unit 17W.
Specifically, the diagnostic unit 57 determines whether the load fluctuation in the U-phase power line 21U to which the first electric heater 48U (load fluctuation ± 500W) is connected is in the range of −250W or less and the range of 250W or more. .. Further, the diagnostic unit 57 determines whether the load fluctuation in the W-phase power line 21W to which the second electric heater 48W is cut and the power load 35b in the second facility is connected is in the range larger than −250W and less than 250W. judge. That is, the diagnosis unit 57 determines whether or not the absolute value of the load fluctuation in the U-phase power line 21U is 250 W or more, and whether or not the absolute value of the load fluctuation in the W-phase power line 21 W is less than 250 W.

When the absolute value of the load fluctuation on the U-phase power line 21U is 250 W or more and the absolute value of the load fluctuation on the W-phase power line 21 W is less than 250 W, the diagnostic unit 57 sets the U-phase side CT diagnostic condition Yu. It is determined that the condition is satisfied, and the U-phase current detection unit 17U diagnoses as normal.

Next, a case of diagnosing whether or not the W-phase current detection unit 17W is normal will be described.
In the case where the diagnosis unit 57 is in the W phase load state in which the second electric heater 48W is connected to the W phase power line 21W, the load fluctuation in the U phase power line 21U and the load fluctuation in the W phase power line 21W are the W phase shown in FIG. It is determined whether or not the side CT diagnostic condition Yw is satisfied. Specifically, in the diagnostic unit 57, the load fluctuation in the U-phase power line 21U to which the first electric heater 48U is cut and the power load 35a in the first facility is connected is in a range larger than −250W and less than 250W. Is determined. Further, the diagnostic unit 57 determines whether the load fluctuation in the W-phase power line 21W to which the second electric heater 48W (load fluctuation ± 500W) is connected is in the range of −250W or less and the range of 250W or more. That is, the diagnosis unit 57 determines whether or not the absolute value of the load fluctuation in the U-phase power line 21U is less than 250 W, and whether or not the absolute value of the load fluctuation in the W-phase power line 21 W is 250 W or more.

When the absolute value of the load fluctuation on the U-phase power line 21U is less than 250 W and the absolute value of the load fluctuation on the W-phase power line 21 W is 250 W or more, the diagnostic unit 57 sets the W-phase side CT diagnostic condition Yw. It is determined that the condition is satisfied, and the W-phase current detection unit 17W diagnoses as normal.

(F) Power generation control unit The power generation control unit 59 controls various operations such as start of operation, maintenance of operation, and stop of operation of the distributed power generation device 15. Further, the power generation control unit 59 controls the switch 12 to control the disconnection and connection between the distributed power generation device 15 and the system power supply 10.

(2) Flow of First CT Diagnosis Process An example of the flow of the CT diagnosis process (hereinafter, may be referred to as the first CT diagnosis process) carried out in the first embodiment will be described with reference to FIGS. 4 and 5.

(2-1) Overall Flow of First CT Diagnostic Process The overall flow of the first CT diagnostic process will be described with reference to FIG.
Steps S10 and S30: The diagnostic availability determination unit 53 performs a pre-determination process on whether or not the load fluctuation in the U-phase power line 21U and the load fluctuation in the W-phase power line 21W are small. The pre-judgment process will be described later.

Step S50: When the heater control unit 51 determines that the U-phase current detection unit 17U can detect the current value (U) by the diagnosis availability determination unit 53, that is, the U-phase current detection unit 17U can diagnose. In order to diagnose the U-phase current detection unit 17U, the connection state of the load to the power line 21 is set to the U-phase load state. The diagnosis unit 57 determines whether or not the load fluctuation in the U-phase power line 21U and the load fluctuation in the W-phase power line 21W satisfy the U-phase side CT diagnostic condition Yu shown in FIG. 3 in the U-phase load state. .. Then, when the U-phase side CT diagnostic condition Yu is satisfied, the diagnostic unit 57 diagnoses that the U-phase current detection unit 17U is normal.

Further, when the heater control unit 51 determines that the W-phase current detection unit 17W can detect the current value (W) by the diagnosis availability determination unit 53, that is, the W-phase current detection unit 17W can diagnose, W In order to diagnose the phase current detection unit 17W, the connection state of the load to the power line 21 is set to the W phase load state. The diagnosis unit 57 determines whether or not the load fluctuation in the U-phase power line 21U and the load fluctuation in the W-phase power line 21W satisfy the W-phase side CT diagnostic condition Yw shown in FIG. 3 in the W-phase load state. .. Then, when the W-phase side CT diagnostic condition Yw is satisfied, the diagnostic unit 57 diagnoses that the W-phase current detection unit 17W is normal.

(2-2) Overall Flow of Pre-determination Process The flow of the pre-determination process in step S10 (or step S30) of FIG. 4 will be described with reference to FIG.
Step S11: The diagnosis possibility determination unit 53 determines whether or not the U-phase current detection unit 17U has been diagnosed, and if not, proceeds to step S12. If the diagnosis has been made, the process proceeds to step S17.

Step S12: The diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the acquired W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw with reference to the load fluctuation determination condition of FIG.

Step S13: When the absolute value of the load fluctuation in the W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw (Yes in step S12), the diagnostic enable / disable determination unit 53 uses the U-phase current detection unit 17U to perform the U-phase. It is determined that the current value (U) for diagnosing the current detection unit 17U can be detected. That is, the diagnostic possibility determination unit 53 determines whether or not the U-phase current detection unit 17U is normal or not.

Step S14: On the other hand, when the absolute value of the load fluctuation in the W-phase power line 21W is not less than the W-phase side load fluctuation determination value Xw (No in step S12), the diagnostic enable / disable determination unit 53 uses the U-phase current detection unit 17U. , The current value (U) for diagnosing the U-phase current detection unit 17U is determined to be undetectable. That is, the diagnostic enable / disable determination unit 53 determines whether or not the U-phase current detection unit 17U is normal or not.

Step S15: The notification unit 55 receives a command from the diagnosis availability determination unit 53 to notify that the use of the power load 35 in the facility is to be withheld, and executes the command. When the user who receives the notification of the notification unit 55 refrains from using the power load 35 in the facility, the load fluctuation due to the power load 35 in the facility can be suppressed. As a result, the U-phase side load fluctuation determination value Xu and the W-phase side load fluctuation determination value Xw are easily satisfied, and the U-phase current detection unit 17U and the W-phase current detection unit 17W can be diagnosed.
Steps S16, S17: The diagnosis possibility determination unit 53 determines whether or not the W-phase current detection unit 17W has been diagnosed when the predetermined time has elapsed (Yes in step S16), and when it has not been diagnosed (in step S17). No) proceeds to step S18. If the diagnosis has been completed (Yes in step S17), the process proceeds to step S23. If the predetermined time has not elapsed (No in step S16), the diagnosis possibility determination unit 53 proceeds to step S12 again.

Step S18: The diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the acquired U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu with reference to the load fluctuation determination condition of FIG.

Step S19: When the absolute value of the load fluctuation in the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu (Yes in step S18), the diagnosis enable / disable determination unit 53 uses the W-phase current detection unit 17W to perform the W-phase. It is determined that the current value (W) for diagnosing the current detection unit 17W can be detected. That is, the diagnostic possibility determination unit 53 determines whether or not the W-phase current detection unit 17W is normal or not.

Step S20: On the other hand, when the absolute value of the load fluctuation in the U-phase power line 21U is not less than the U-phase side load fluctuation determination value Xu (No in step S18), the diagnosis possibility determination unit 53 uses the W-phase current detection unit 17W. , The current value (W) for diagnosing the W-phase current detection unit 17W is determined to be undetectable. That is, the diagnostic enable / disable determination unit 53 determines whether or not the W-phase current detection unit 17W is normal or not.

Step S21: The notification unit 55 receives a command from the diagnosis / rejection determination unit 53 to notify that the use of the power load 35 in the facility is to be withheld, and executes the command.
Steps S22 and S23: The diagnostic enable / disable determination unit 53 determines whether or not to end the process when the predetermined time has elapsed (Yes in step S22), and if it does not end (No in step S23), the process proceeds to step S11. Proceed with processing. When it ends (Yes in step S23), the process ends. If the predetermined time has not elapsed (No in step S22), the diagnosis possibility determination unit 53 proceeds to step S18 again.

According to the first embodiment, as described above, it is possible to suppress an erroneous diagnosis as to whether or not the U-phase current detection unit 17U and the W-phase current detection unit 17W are normal.

Further, in the above processing, if a predetermined time elapses when it becomes impossible to diagnose whether or not the U-phase current detection unit 17U is normal in steps S12 and S14 (Yes in step S16), the W-phase current in steps S17 and thereafter. The process proceeds to determine whether or not the detection unit 17W can be diagnosed. Similarly, if it becomes impossible to diagnose whether or not the W-phase current detection unit 17W is normal in steps S18 and S20 and a predetermined time elapses (Yes in step S22), the process returns to step S11 and the U-phase current is detected. The process moves to whether or not the diagnosis of the unit 17U is possible. Therefore, depending on the load fluctuation status of the U-phase power line 21U and the W-phase power line 21W, the current detection unit 17 of the U-phase current detection unit 17U or the W-phase current detection unit 17W can be flexibly adapted for diagnosis. Can be done.

When the first electric heater 48U is connected to the U-phase power line 21U in order to diagnose the U-phase current detection unit 17U, the load fluctuation of the U-phase power line 21U is mainly caused by the first electric heater 48U. On the other hand, in the W-phase power line 21W, load fluctuation occurs due to the power load 35b in the second facility. Here, as described above, when the absolute value of the load fluctuation in the W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw, the U-phase current detection unit 17U is diagnosed. When the absolute value of the load fluctuation on the W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw, the absolute value of the load fluctuation due to the power load 35b in the second facility on the W-phase power line 21W is the power consumption of the first electric heater 48U. It is less than the load fluctuation due to. In this case, the absolute value of the load fluctuation caused by the first electric heater 48U generated in the U-phase power line 21U becomes larger than the absolute value of the load fluctuation caused by the second facility power load 35b generated in the W-phase power line 21W. Therefore, the behavior of the load fluctuation due to the first electric heater 48U of the U-phase power line 21U and the behavior of the load fluctuation due to the power load 35b in the second facility of the W-phase power line 21W are different, and the U-phase power line 21U and the W-phase power line 21W are separated. Can be distinguished. Then, in the U-phase load state, it is possible to easily diagnose whether or not the U-phase current detection unit 17U is normal depending on whether or not the U-phase current detection unit 17U detects a large load fluctuation in the U-phase power line 21U.

Similarly, when the second electric heater 48W is connected to the W-phase power line 21W in order to diagnose the W-phase current detection unit 17W, the load fluctuation of the W-phase power line 21W is mainly caused by the second electric heater 48W. On the other hand, in the U-phase power line 21U, load fluctuation occurs due to the power load 35a in the first facility. Here, as described above, when the absolute value of the load fluctuation in the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu, the W-phase current detection unit 17W is diagnosed. When the absolute value of the load fluctuation on the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu, the absolute value of the load fluctuation due to the power load 35a in the first facility on the U-phase power line 21U is the power consumption of the second electric heater 48W. It is less than the load fluctuation due to. In this case, the absolute value of the load fluctuation caused by the second electric heater 48W generated in the W-phase power line 21W becomes larger than the absolute value of the load fluctuation caused by the first facility power load 35a generated in the U-phase power line 21U. Therefore, the behavior of the load fluctuation of the U-phase power line 21U and the behavior of the load fluctuation of the W-phase power line 21W are different, and the U-phase power line 21U and the W-phase power line 21W can be distinguished from each other. Then, in the W-phase load state, it is possible to easily diagnose whether or not the W-phase current detection unit 17W is normal depending on whether or not the W-phase current detection unit 17W detects a large load fluctuation in the W-phase power line 21W.

(3) Modification example of the first embodiment (3-1)
In the first embodiment, the U-phase side load fluctuation determination value Xu and the W-phase side load fluctuation determination value Xw in FIG. 2 are fixed values, but may be changed. Such a modification of the first embodiment will be described with reference to the pre-determination process (step S30) of FIG. 6 and FIG. 7. Since steps S31 to S43 are the same as steps S11 to S23, the description thereof will be omitted or simplified.

Steps S31 to S35: The same as steps S11 to S15.
Step S44: After step S35, the diagnosis possibility determination unit 53 determines the W-phase side load when the absolute value of the load fluctuation in the W-phase power line 21W is not less than the W-phase side load fluctuation determination value Xw (No in step S32). It is determined whether or not to change the fluctuation determination value Xw. Whether or not to change is set in advance, for example.

Step S45: When the diagnosis possibility determination unit 53 determines that the W phase side load fluctuation determination value Xw is to be changed (Yes in step S44), the W phase side load fluctuation determination value Xw is changed.
For example, the diagnosis possibility determination unit 53 is changed so as to expand the W phase side load fluctuation determination value Xw. Note that extension means changing the setting so that the original value (absolute value) becomes a larger value (absolute value), and the same applies to the following. Specifically, in FIG. 2, the W-phase side load fluctuation determination value Xw is ± 250 W, but the diagnosis possibility determination unit 53 expands the W-phase side load fluctuation determination value Xw to ± 300 W as shown in FIG. To change. As a result, when the absolute value of the load fluctuation on the W-phase power line 21W is larger than 250W but less than 300W, it is determined that the load fluctuation on the W-phase power line 21W is small.
Here, as shown in FIG. 7, the case where the W-phase side load fluctuation determination value Xw is expanded from ± 250 W to ± 300 W is shown as an example, but a plurality of cases are shown within the range of the power consumption (for example, ± 500 W) of the electric heater 48. It can also be expanded in stages.
The diagnosis possibility determination unit 53 executes step S32 again after expanding the W-phase side load fluctuation determination value Xw.
Step S36: Further, when the diagnosis possibility determination unit 53 determines in step S44 that the W phase side load fluctuation determination value Xw is not changed (No in step S44), the predetermined time has elapsed (Yes in step S36). ) Proceeds to step S37, and if not, the process proceeds to step S32 again.

Steps S37 to S41: The same as steps S17 to S21.
Step S46: After step S41, the diagnosis possibility determination unit 53 determines the U-phase side load when the absolute value of the load fluctuation in the U-phase power line 21U is not less than the U-phase side load fluctuation determination value Xu (No in step S38). It is determined whether or not to change the fluctuation determination value Xu. Whether or not to change is set in advance, for example.

Step S47: When the diagnosis possibility determination unit 53 determines that the U-phase side load fluctuation determination value Xu is to be changed (Yes in step S46), the U-phase side load fluctuation determination value Xu is changed.
For example, the diagnosis possibility determination unit 53 changes the U-phase side load fluctuation determination value Xu to ± 300 W, as shown in FIG. 7, for example. The diagnosis possibility determination unit 53 executes step S38 again after expanding the U-phase side load fluctuation determination value Xu. Similar to the W-phase load fluctuation determination value Xw, the U-phase load fluctuation determination value Xu can be expanded in a plurality of steps within the range of the power consumption (for example, ± 500 W) of the electric heater 48.

Step S42: Further, when the diagnosis possibility determination unit 53 determines in step S46 that the U-phase side load fluctuation determination value Xu is not changed (No in step S46), when a predetermined time has elapsed (Yes in step S42). ) Proceed to step S43, and if not, the process proceeds to step S38 again.
Step S43: This is the same process as in step S23.

By expanding the load fluctuation determination value as described above, the current value required for the diagnosis of the current detection unit 17 can be detected so that the absolute value of the load fluctuation in the power line 21 becomes less than the load fluctuation determination value. Therefore, it is possible to prevent the current detection unit 17 from being unable to diagnose continuously.

It should be noted that the initial setting may be made as to whether or not the load fluctuation determination value is changed according to the difference between the absolute value of the load variation on the W-phase power line 21W and the W-phase side load variation determination value Xw. For example, when the absolute value of the load fluctuation on the W-phase power line 21W is larger than the W-phase side load fluctuation determination value Xw and the amount is equal to or greater than a predetermined value, the W-phase side load fluctuation determination value Xw is set to be changed. On the other hand, for example, when the absolute value of the load fluctuation on the W-phase power line 21W is larger than the W-phase side load fluctuation determination value Xw and the amount is less than a predetermined value, it is set that the W-phase side load fluctuation determination value Xw is not changed. There is. The same applies to the U-phase side load fluctuation determination value Xu.
On the contrary, the initial setting that the reference value cannot be changed may be made.

(3-2)
In the first embodiment, the diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu, and the absolute value of the load fluctuation in the W-phase power line 21W is W. It is determined whether or not the phase load fluctuation determination value is less than Xw. However, it may be determined whether or not the sum of the absolute value of the load fluctuation on the U-phase power line 21U and the absolute value of the load fluctuation on the W-phase power line 21W is less than a predetermined load fluctuation determination value.

[Second Embodiment]
Hereinafter, the distributed power generation system according to the second embodiment will be described with reference to FIG. In the present embodiment, as a method for improving the diagnosis of the current detection unit, a process of changing the flow of the CT diagnosis process at any time is performed.

(1) Overall Configuration As the overall configuration of the distributed power generation system according to the second embodiment, the control unit 50 does not have the diagnosis possibility determination unit 53 of the first embodiment. Further, the control unit 50 of the second embodiment does not have the load fluctuation determination condition shown in FIG. 2 in the storage unit 58 of the first embodiment. Further, the heater control unit 51 has a U-phase load state (an example of a first-phase load state) and a W-phase load state (an example of a second-phase load state) regardless of whether the diagnosis is possible or not. ).
Further, the diagnostic unit 57 of the control unit 50 of the second embodiment refers to the CT diagnostic conditions in the same manner as the diagnostic unit 57 of the control unit 50 of the first embodiment, and determines whether the U-phase current detection unit 17U is normal or not. And, it is diagnosed whether or not the W phase current detection unit 17W is normal. In addition, the diagnosis unit 57 can change the order of diagnosis of the U-phase current detection unit 17U and the W-phase current detection unit 17W. Since other points are the same as the overall configuration of the first embodiment, the description thereof will be omitted.

(2) Flow of Second CT Diagnosis Process An example of the flow of the CT diagnosis process (hereinafter, may be referred to as the second CT diagnosis process (step S60)) performed in the second embodiment will be described with reference to FIG. The second CT diagnostic process is different from the first CT diagnostic process of the first embodiment, and the pre-determination process is not performed.
Step S61: The diagnosis unit 57 determines whether or not the U-phase current detection unit 17U has been diagnosed, and if it has not been diagnosed (No in step S61), the process proceeds to step S62. If the diagnosis has been completed (Yes in step S61), the process proceeds to step S67.

Step S62: The heater control unit 51 sets the connection state of the load to the power line 21 to the U-phase load state (an example of the first-phase load state) in order to diagnose the U-phase current detection unit 17U (U-phase load). Input: Input of the first electric heater (an example of the first phase load).
Step S63: The diagnosis unit 57 refers to the CT diagnosis condition of FIG. 3, diagnoses whether or not the U-phase side CT diagnosis condition Yu is satisfied, and diagnoses whether or not the U-phase current detection unit 17U is normal. In the case of FIG. 3, the diagnostic unit 57 has an absolute value of the load fluctuation (U-phase side load fluctuation) in the U-phase power line 21U of 250 W or more, and the load fluctuation in the W-phase power line 21 W (W-phase side load fluctuation). When the absolute value is less than 250 W, the U-phase current detection unit 17U is diagnosed as normal. On the other hand, if the U-phase side CT diagnostic condition Yu is not satisfied, the U-phase current detection unit 17U diagnoses as abnormal and proceeds to step S65.
Step S64: When the U-phase side CT diagnostic condition Yu is satisfied, the diagnostic unit 57 diagnoses that the U-phase current detection unit 17U is normal.

Step S65: The notification unit 55 receives a command from the diagnosis unit 57 to notify that the use of the power load 35 in the facility is to be withheld, and executes the command.
Step S66: If the predetermined time has not elapsed (No in step S66), the diagnosis unit 57 proceeds to step S62. When the predetermined time has elapsed (Yes in step S66), the process proceeds to step S67.
Step S67: The diagnosis unit 57 determines whether or not the W-phase current detection unit 17W has been diagnosed, and if it has not been diagnosed (No in step S67), the process proceeds to step S68. If the diagnosis has been made (Yes in step S67), the process proceeds to step S73.

Step S68: The heater control unit 51 sets the connection state of the load to the power line 21 to the W phase load state (an example of the second phase load state) in order to diagnose the W phase current detection unit 17W (W phase load). Input: Input of the second electric heater (an example of the second phase load).
Step S69: The diagnosis unit 57 refers to the CT diagnosis condition of FIG. 3, diagnoses whether or not the W-phase side CT diagnosis condition Yw is satisfied, and diagnoses whether or not the W-phase current detection unit 17W is normal. In the case of FIG. 3, the diagnostic unit 57 has an absolute value of the load fluctuation (W-phase side load fluctuation) in the W-phase power line 21W of 250 W or more, and the load fluctuation in the U-phase power line 21U (U-phase side load fluctuation). When the absolute value is less than 250 W, the U-phase current detection unit 17U is diagnosed as normal. On the other hand, if the W-phase side CT diagnostic condition Yw is not satisfied, the W-phase current detection unit 17W diagnoses as abnormal and proceeds to step S71.
Step S70: When the W-phase side CT diagnostic condition Yw is satisfied, the diagnostic unit 57 diagnoses that the W-phase current detection unit 17W is normal.

Step S71: The notification unit 55 receives a command from the diagnosis unit 57 to notify that the use of the power load 35 in the facility is to be withheld, and executes the command.
Step S72: If the predetermined time has not elapsed (No in step S72), the diagnosis unit 57 proceeds to step S68. When the predetermined time has elapsed (Yes in step S72), the diagnosis unit 57 proceeds to step S73.
Step S73: If the diagnosis unit 57 does not end the process (No in step S73), the process proceeds to step S61, and if not (Yes in step S73), the process ends. For example, if both the U-phase current detection unit 17U and the W-phase current detection unit 17W have been diagnosed, the diagnosis unit 57 ends the process, and at least one of the U-phase current detection unit 17U and the W-phase current detection unit 17W. If the above has not been diagnosed yet, the process proceeds to step S61. In addition, the diagnostic unit 57 ends the process when the diagnostic results of both the U-phase current detection unit 17U and the W-phase current detection unit 17W are normal, and the U-phase current detection unit 17U and the W-phase current detection unit 17W If at least one of the diagnosis results is not normal, the process can proceed to step S61.

Further, in the above process, if the U-phase current detection unit 17U is not normal in step S63 and a predetermined time elapses (No in step S66), the diagnosis of the W-phase current detection unit 17W proceeds in step S67 and thereafter. Similarly, if the W-phase current detection unit 17W is not normal in step S69 and a predetermined time elapses (Yes in step S72), it is possible to return to step S61 or later to diagnose the U-phase current detection unit 17U. Move on to processing. Therefore, depending on the load fluctuation status of the U-phase power line 21U and the W-phase power line 21W, the current detection unit 17 of the U-phase current detection unit 17U or the W-phase current detection unit 17W can be flexibly adapted for diagnosis. Can be done.

Further, when the user who receives the notification of the notification unit 55 refrains from using the power load 35 in the facility, the load fluctuation due to the power load 35 in the facility can be suppressed. As a result, the U-phase side CT diagnostic condition Yu and the W-phase side CT diagnostic condition Yw can be easily satisfied, and the U-phase current detection unit 17U and the W-phase current detection unit 17W can be easily diagnosed.

The U-phase side CT diagnostic condition Yu for diagnosing the U-phase current detection unit 17U is set based on the load fluctuation caused by the first electric heater 48U. For example, as shown in FIG. 3, the load fluctuation due to the first electric heater 48U is 500 W, and the U-phase side CT diagnostic condition Yu is based on 250 W in which the U-phase side load fluctuation and the W-phase side load fluctuation are smaller than 500 W. It has been set. In this case, the behavior of the load fluctuation due to the first electric heater 48U of the U-phase power line 21U and the behavior of the load fluctuation due to the power load 35b in the second facility of the W-phase power line 21W can be distinguished. Then, it is possible to easily diagnose whether or not the U-phase current detection unit 17U is normal depending on whether or not the U-phase current detection unit 17U detects a large load fluctuation in the U-phase power line 21U.

The W-phase side CT diagnostic condition Yw for diagnosing the W-phase current detection unit 17W is set based on the load fluctuation due to the second electric heater 48W. For example, as shown in FIG. 3, the load fluctuation due to the second electric heater 48W is 500W, and the W-phase side CT diagnostic condition Yw is based on 250W in which the U-phase side load fluctuation and the W-phase side load fluctuation are smaller than 500W. It has been set. In this case, it is possible to distinguish between the behavior of the load fluctuation due to the second electric heater 48W of the W-phase power line 21W and the behavior of the load fluctuation due to the power load 35a in the first facility of the U-phase power line 21U. Then, it is possible to easily diagnose whether or not the W-phase current detection unit 17W is normal depending on whether or not the W-phase current detection unit 17W detects a large load fluctuation in the W-phase power line 21W.

(3) Modification example of the second embodiment (3-1)
In the second embodiment, the U-phase CT diagnostic condition Yu and the W-phase CT diagnostic condition Yw in FIG. 3 are fixed values, but may be changed. The second CT diagnostic process (step S80) according to such a modified example of the second embodiment will be described with reference to FIGS. 9 and 10. Since steps S81 to S93 are the same as steps S61 to S73, the description thereof will be omitted or simplified.

Steps S81-S85: The same as steps S61-S65.
Step S94: After step S85, if the diagnostic unit 57 does not satisfy the U-phase CT diagnostic condition Yu (No in step S83), the diagnostic unit 57 determines whether or not to change the U-phase CT diagnostic condition Yu. Whether or not to change is set in advance, for example.

Step S95: When the diagnostic unit 57 determines that the U-phase CT diagnostic condition Yu is changed (Yes in step S94), the U-phase CT diagnostic condition Yu is changed.
For example, the diagnostic unit 57 changes the U-phase side CT diagnostic condition Yu to be extended. For example, in FIG. 3, the U-phase CT diagnostic condition Yu is ± 250 W, but the diagnostic unit 57 changes the U-phase CT diagnostic condition Yu to ± 300 W as shown in FIG. Specifically, as the U-phase side CT diagnostic condition Yu, the load fluctuation on the U-phase power line 21U (U-phase side load fluctuation in FIG. 3) is changed to ± 300 W or more, and the load fluctuation on the W-phase power line 21 W (FIG. 3). The W-phase side load fluctuation in 3) is changed to less than ± 300W. As a result, the diagnostic conditions of the U-phase current detection unit 17U are extended.
Here, as shown in FIG. 10, the case where the U-phase side CT diagnostic condition Yu is changed from ± 250 W to ± 300 W is shown as an example, but the range of the power consumption (for example, ± 500 W) of the first electric heater 48U is shown. It can also be expanded in multiple stages within.
The diagnosis possibility determination unit 53 executes step S82 again after expanding the U-phase side CT diagnosis condition Yu.

Step S86: Further, when the diagnosis unit 57 determines in step S94 that the U-phase side CT diagnostic condition Yu is not changed (No in step S94), when a predetermined time has elapsed (Yes in step S86), The process proceeds to step S87, and if not, the process proceeds to step S82 again.

Steps S87 to S91: The same as steps S67 to S71.
Step S96: After step S91, if the diagnosis unit 57 does not satisfy the W-phase CT diagnostic condition Yw (No in step S89), the diagnostic unit 57 determines whether or not to change the W-phase CT diagnostic condition Yw. Whether or not to change is set in advance, for example.

Step S97: When the diagnostic unit 57 determines that the W-phase CT diagnostic condition Yw is to be changed (Yes in step S96), the W-phase CT diagnostic condition Yw is changed.
For example, the diagnostic unit 57 changes the W-phase side CT diagnostic condition Yw to be extended. For example, in FIG. 3, the W-phase CT diagnostic condition Yw is ± 250 W, but the diagnostic unit 57 changes the W-phase CT diagnostic condition Yw to ± 300 W as shown in FIG. Specifically, as the W-phase side CT diagnostic condition Yw, the load fluctuation on the U-phase power line 21U (U-phase side load fluctuation in FIG. 3) is changed to less than ± 300 W, and the load fluctuation on the W-phase power line 21W (FIG. 3). The W-phase side load fluctuation in 3) is changed to ± 300 W or more. As a result, the diagnostic conditions of the W-phase current detection unit 17W are extended. Similar to the U-phase CT diagnostic condition Yu, the W-phase CT diagnostic condition Yw can be extended in a plurality of steps within the range of the power consumption (for example, ± 500 W) of the second electric heater 48 W.
The diagnostic unit 57 executes step S88 again after expanding the W-phase side CT diagnostic condition Yw.

Step S92: Further, when the diagnosis unit 57 determines in step S96 that the W phase side CT diagnostic condition Yw is not changed (No in step S96), when a predetermined time has elapsed (Yes in step S92), The process proceeds to step S93, and if not, the process proceeds to step S88 again.
Step S93: The same process as in step S73.

As in the above process, the U-phase side CT diagnostic condition Yu and the W-phase side CT diagnostic condition Yw are extended so that the range of load fluctuation becomes large. As a result, it is possible to prevent the situation in which the U-phase CT diagnostic condition Yu and the W-phase CT diagnostic condition Yw are not satisfied continue. As a result, it is possible to prevent the situation in which the distributed power generation device 15 cannot generate power continues.

(3-2)
In the process of the second embodiment, the pre-determination process shown in the first embodiment may be performed.
(A)
The second CT diagnostic process shown in FIG. 8 of the second embodiment is not limited to this, and for example, the pre-determination process of the first embodiment can be performed at the timing shown in FIG. In FIG. 11, the same processing numbers as those in FIG. 8 are shown, and the description thereof will be omitted.

Step S101: When the U-phase side CT diagnosis condition Yu is not satisfied in step S63 (No in step S63), the diagnosis possibility determination unit 53 refers to the load fluctuation determination condition of FIG. 2 and obtains the W-phase power line 21W. It is determined whether or not the absolute value of the load fluctuation is less than the W phase side load fluctuation determination value Xw.

Step S102: When the absolute value of the load fluctuation in the W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw (Yes in step S101), the diagnostic enable / disable determination unit 53 uses the U-phase current detection unit 17U to perform the U-phase. It is determined that the current value (U) for diagnosing the current detection unit 17U can be detected. That is, the diagnostic possibility determination unit 53 determines whether or not the U-phase current detection unit 17U is normal or not. After that, the process of step S62 proceeds.

Step S103: On the other hand, when the absolute value of the load fluctuation in the W-phase power line 21W is not less than the W-phase side load fluctuation determination value Xw (No in step S101), the diagnosis possibility determination unit 53 uses the U-phase current detection unit 17U. , The current value (U) for diagnosing the U-phase current detection unit 17U is determined to be undetectable. That is, the diagnostic enable / disable determination unit 53 determines whether or not the U-phase current detection unit 17U is normal or not. After that, the process of step S65 proceeds.

Step S104: When the W-phase side CT diagnosis condition Yw is not satisfied in step S69 (No in step S69), the diagnosis possibility determination unit 53 determines that the absolute value of the load fluctuation in the acquired U-phase power line 21U is the U-phase side load fluctuation. It is determined whether or not the determination value is less than Xu.

Step S105: When the absolute value of the load fluctuation in the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu (Yes in step S104), the diagnosis enable / disable determination unit 53 uses the W-phase current detection unit 17W to perform the W-phase. It is determined that the current value (W) for diagnosing the current detection unit 17W can be detected. That is, the diagnostic possibility determination unit 53 determines whether or not the W-phase current detection unit 17W is normal or not. After that, the process of step S68 proceeds.

Step S106: On the other hand, when the absolute value of the load fluctuation in the U-phase power line 21U is not less than the U-phase side load fluctuation determination value Xu (No in step S104), the diagnosis possibility determination unit 53 uses the W-phase current detection unit 17W. , The current value (W) for diagnosing the W-phase current detection unit 17W is determined to be undetectable. That is, the diagnostic enable / disable determination unit 53 determines whether or not the W-phase current detection unit 17W is normal or not. After that, the process of step S71 proceeds.

(B)
The second CT diagnostic process shown in FIG. 9 shown in the modified example of the second embodiment of (3-1) is not limited to this, but for example, the pre-determination process of the first embodiment is performed at the timing shown in FIG. be able to. In FIG. 12, the same processing numbers as those in FIG. 9 are shown, and the description thereof will be omitted. Further, in FIG. 12, steps S201 to S206 are the same processes as steps S101 to S106 in FIG. 11, and the description thereof will be simplified.

Step S201: After changing the U-phase side CT diagnosis condition Yu in step S95, the diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw. ..
Step S202: When the absolute value of the load fluctuation in the W-phase power line 21W is less than the W-phase side load fluctuation determination value Xw (Yes in step S201), the diagnostic enable / disable determination unit 53 determines that the U-phase current detection unit 17U can be diagnosed. decide. After that, the process of step S82 proceeds.

Step S203: On the other hand, when the absolute value of the load fluctuation in the W-phase power line 21W is not less than the W-phase side load fluctuation determination value Xw (No in step S201), the diagnosis possibility determination unit 53 uses the U-phase current detection unit 17U. Determined to be undiagnosable. After that, the process of step S87 proceeds.

Step S204: After changing the U-phase side CT diagnosis condition Yu in step S96, the diagnosis possibility determination unit 53 determines whether or not the absolute value of the load fluctuation in the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu. ..
Step S205: When the absolute value of the load fluctuation in the U-phase power line 21U is less than the U-phase side load fluctuation determination value Xu (Yes in step S204), the diagnostic enable / disable determination unit 53 determines that the W-phase current detection unit 17W can be diagnosed. decide. After that, the process of step S88 proceeds.

Step S206: On the other hand, when the absolute value of the load fluctuation in the U-phase power line 21U is not less than the U-phase side load fluctuation determination value Xu (No in step S204), the diagnosis possibility determination unit 53 uses the W-phase current detection unit 17W. Determined to be undiagnosable. After that, the process of step S93 proceeds.

[Other Embodiments]
(1)
In the first and second embodiments, the timing of the first CT diagnostic process of the first embodiment and the second CT diagnostic process of the second embodiment (hereinafter collectively referred to as CT diagnostic process) is not particularly limited. The CT diagnostic process can be performed at the following timing, for example.

(1-1) CT diagnosis processing before the start of power generation The CT diagnosis processing can be performed before the start of power generation by the distributed power generation device 15, and the U-phase power line 21U and the W-phase power line 21W have grids. System power is supplied from the power source 10. The process of performing the CT diagnosis process at such a timing will be described with reference to FIG.

Step S300: The diagnosis unit 57 determines whether or not the CT diagnosis process has been completed, and if the CT diagnosis process has not been completed (No in step S300), the process proceeds to step S301.

Step S301: When the CT diagnosis process is started but the CT diagnosis process is not completed yet, the diagnosis unit 57 starts the power generation control unit 59 in order to enable power generation by the distributed power generation device 15. To advance.
The case where the CT diagnosis process is not completed is the case where the diagnosis unit 57 determines that the diagnosis of either the U-phase current detection unit 17U or the W-phase current detection unit 17W is impossible.
In addition, examples of the start-up process required to enable power generation include raising the temperature of the reformer and gradually raising the temperature of the cell.
If the required start-up process is started and the start-up process proceeds after a predetermined time has elapsed (Yes in step S302), the diagnosis unit 57 proceeds with the CT diagnosis process.

In this way, by performing the start-up process required to enable power generation by the distributed power generation device 15 prior to the CT diagnosis process, the time required for the diagnosis of the current detection unit 17 and the process including various start-up processes. Can be suppressed from prolonging.

Step S303: When the CT diagnosis process is completed (Yes in step S300), when the diagnosis unit 57 notifies that the U-phase current detection unit 17U and the W-phase current detection unit 17W are normal, power generation control is performed. The unit 59 starts power generation in the distributed power generation device 15.

(1-2) CT diagnostic processing during idling or within a predetermined time after the start of stop processing (1-2-1)
The CT diagnostic process can be performed when the distributed power generation device 15 is set to the idling state after starting power generation. The process of performing the CT diagnosis process at such a timing will be described with reference to FIG.

Steps S310 and S311: When the distributed power generation device 15 is generating power, the diagnosis unit 57 determines whether or not it is the timing of the CT diagnosis process.
The timing of the CT diagnosis process is set in advance according to, for example, the timing of periodic maintenance and cycle stop.

Step S312: When the timing of the CT diagnosis process is reached (Yes in step S311), the diagnosis unit 57 determines whether or not the idling state is set.
Here, when the maintenance time is approaching and there is a possibility that the power generation in the distributed power generation device 15 is stopped, or the load fluctuation in the power line 21 is smaller than in other time zones, the power generation in the distributed power generation device 15 is performed. If there is a possibility of stopping, the distributed power generation device 15 is set to the idling state. That is, the idling state includes a state in which the distributed power generation device 15 stops generating power after the distributed power generation device 15 starts power generation. Further, the idling state may include a state in which the distributed power generation device 15 does not output the generated power, that is, a state in which the power conversion device 13 does not output the generated power to the system power source 10 although the distributed power generation device 15 is generating power. ..
When the diagnosis unit 57 determines that the idling state is determined, the diagnosis unit 57 proceeds with the CT diagnosis process.
In the idling state as described above, it can be estimated that the demand for the power generated by the distributed power generation device 15 is decreasing, and the use of the power load 35 in the facility is decreasing. Therefore, the power load 35 in the facility is connected to the power line 21 as the load in the facility, but in the idling state, the absolute value of the load fluctuation due to the power load 35 in the facility in the power line 21 is less than the load fluctuation determination value. It is easy to become. Therefore, as in the above feature configuration, the current value can be detected by proceeding with the CT diagnosis process when the idling state is reached and determining whether or not the current value can be detected by the current detection unit 17. It is highly possible that it will be.

(1-2-2)
The CT diagnosis process can be performed when the distributed power generation device 15 starts power generation and then falls within a predetermined time from the start of the stop process. The process of performing the CT diagnosis process at such a timing will be described with reference to FIG.

Step S320: When the distributed power generation device 15 is generating power, the diagnosis unit 57 determines whether or not it is the timing of the CT diagnosis process. The timing of the CT diagnosis process is set in advance according to, for example, the timing of periodic maintenance and cycle stop.
Step S321: When the timing of the CT diagnosis process is reached (Yes in step S320), the diagnosis unit 57 determines whether or not it is within a predetermined time from the start of the stop process. If it is within a predetermined time from the start of the stop process (Yes in step S321), the diagnosis unit 57 proceeds with the CT diagnosis process.

The stop processing is often performed when regular maintenance and cycle stop are scheduled, and the demand for the power generated by the distributed power generation device 15 is decreasing, and the use of the power load 35 in the facility is decreasing. Can be estimated. It can be estimated that the same state is obtained within a predetermined time after the start of the stop processing of the distributed power generation device 15. Therefore, the power load 35 in the facility is connected to the power line 21 as the load in the facility, but if it is within a predetermined time from the start of the stop processing, the absolute value of the load fluctuation due to the power load 35 in the facility in the power line 21 is It tends to be less than the load fluctuation judgment value. Therefore, it is highly preferable that the current value can be detected by determining whether or not the current value can be detected by the current detection unit within a predetermined time from the start of the stop processing.

(1-3) CT diagnosis processing at the timing extracted from the load fluctuation acquired at any time The CT diagnosis processing can be performed when the load fluctuation becomes small after the distributed power generation device 15 starts power generation. The process of performing the CT diagnosis process at such a timing will be described with reference to FIGS. 16 and 17.

Step S330: The diagnostic unit 57 acquires the load fluctuation on the power line 21 by using, for example, the U-phase power line 21U and the W-phase power line 21W.

Step S321: The diagnosis unit 57 determines whether or not the timing of the CT diagnosis process is set. Here, the diagnosis unit 57 determines, for example, a case where the absolute value of the load fluctuation is smaller than a predetermined value as the timing of the CT diagnosis processing based on the acquired load fluctuation. For example, the diagnosis unit 57 sets the timing of the CT diagnosis process from 0:00 to 6:00 when the load fluctuation is less than 250 W, for example, based on the time-dependent change of the load fluctuation from 0:00 to 24:00 shown in FIG. decide. In addition, the diagnosis unit 57 may specify a time zone in which the absolute value of the load fluctuation is small as described above by learning the change over time of the load fluctuation of a predetermined facility.
In FIG. 17, the shaded area is a part where the system power is supplied from the system power source 10.
When the diagnosis unit 57 determines that it is the timing of the CT diagnosis process, the diagnosis unit 57 proceeds with the CT diagnosis process.

Since it is determined whether or not the current value can be detected after specifying the timing when the absolute value of the load fluctuation is small, the current value is determined more than when determining whether or not the current value can be detected at an arbitrary timing. It is preferable to be able to determine whether or not detection is possible at a detectable timing.

(2) Prior to the second CT diagnostic process in the second embodiment, the pre-determination process in the first embodiment may be performed.

(3) The following process can be added to the pre-determination process shown in FIG. 5 in the first embodiment. When the diagnostic possibility determination unit 53 determines that the U-phase current detection unit 17U can be diagnosed in step S13 of FIG. 5, the diagnosis unit 57 diagnoses whether the U-phase current detection unit 17U is normal or not as the next process. It can be carried out. Further, when the diagnosis possibility determination unit 53 determines that the diagnosis is possible for the W phase current detection unit 17W in step S19 of FIG. 5, the diagnosis unit 57 determines whether the W phase current detection unit 17W is normal or not as the next process. Diagnosis can be made.
Similarly, in the predetermination process shown in FIG. 6 in the first embodiment, when it is determined in step S33 that the U-phase current detection unit 17U can be diagnosed, the diagnosis unit 57 causes the U-phase current detection unit 17U to make a diagnosis. It is possible to diagnose whether it is normal or not. Further, when it is determined in step S39 that the W-phase current detection unit 17W can be diagnosed, the diagnosis unit 57 can diagnose whether or not the W-phase current detection unit 17W is normal.

(4)
The CT diagnosis processing of the first and second embodiments is performed depending on whether or not the load fluctuation corresponding to the current value detected by the current detection unit 17 satisfies the CT diagnosis condition. However, the CT diagnosis process may include diagnosis of the connection state of the current detection unit 17. Examples of the diagnosis of the connection state include a diagnosis of a poor connection, an error in the connection location, and an error in the connection direction.

The poor connection is, for example, a case where the electrical connection between the U-phase current detection unit 17U and the U-phase power line 21U is disconnected, and the electrical connection between the W-phase current detection unit 17W and the W-phase power line 21W. Is disconnected. An error in the connection location is, for example, a case where the U-phase current detection unit 17U is not connected to the U-phase power line 21U but is connected to another wiring such as the W-phase current detection unit 17W, and W. This is a case where the phase current detection unit 17W is not connected to the W phase power line 21W but is connected to other wiring such as the U phase current detection unit 17U. An error in the connection direction is, for example, a case where the plus and minus of the U-phase current detection unit 17U are interchanged and connected to the U-phase power line 21U, and the plus and minus of the W-phase current detection unit 17W are connected. This is a case where they are alternately connected to the W-phase power line 21W.

(5) In the present embodiment, the value of the load fluctuation on the power line 21 is an instantaneous value of the power measured on the power line 21 at a certain time point. However, the value of the load fluctuation may not be the value at the moment, but may be the average value of the power values measured on the power line 21 in a predetermined period.

(6) In the present embodiment, a mode in which 100 V of electric power is supplied to the in-facility electric power loads 35a and 35b is illustrated, but 200 V of electric power is applied to the in-facility electric power loads 35a and 35b as needed. May be supplied.

The configurations disclosed in the above-described embodiments (including other embodiments, the same shall apply hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as there is no contradiction. , The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

10: System power supply 15: Distributed power generation device 17: Current detection unit 17U: U-phase current detection unit (first current detection unit)
17W: W-phase current detector (second current detector)
21: Power line 21N: Neutral line 21U: U-phase power line (Phase 1 power line)
21W: W phase power line (second phase power line)
35: Power load in the facility (third load)
48: Electric heater (phase load)
48U: 1st electric heater (1st phase load)
48W: Second electric heater (first phase load)
51: Heater control unit (phase load control unit)
53: Diagnosis availability determination unit 55: Notification unit 57: Diagnosis unit 100: Distributed power generation system Xu: U-phase side load fluctuation determination value (first load fluctuation determination value)
Xw: W phase side load fluctuation judgment value (second load fluctuation judgment value)
Yu: U-phase side CT diagnostic condition (first diagnostic condition)
Yw: W phase side CT diagnostic condition (second diagnostic condition)

Claims (22)

A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic device that diagnoses whether the current detector is normal or not.
It is determined whether or not the load fluctuation determination condition in which the absolute value of the load fluctuation in the power line is less than the predetermined load fluctuation determination value is satisfied, and when the load fluctuation determination condition is satisfied, the current detection unit performs the current detection unit. A diagnostic device including a diagnostic availability determination unit that determines that a current value for diagnosing whether or not is normal can be detected. The load fluctuation determination value includes a first load fluctuation determination value, which is a standard for determining an absolute value of load fluctuation in the first phase power line, and a standard for determining an absolute value of load fluctuation in the second phase power line. The second load fluctuation judgment value is included,
The load fluctuation determination condition includes a first load fluctuation determination condition for determining whether or not the current value can be detected by the second current detection unit, and a determination as to whether or not the first current detection unit can detect the current value. 2nd load fluctuation judgment condition for
The diagnostic approval / disapproval determination unit
When it is determined that the absolute value of the load fluctuation in the second phase power line is less than the second load fluctuation determination value and the second load fluctuation determination condition is satisfied, the first current detection unit normalizes the first current detection unit. Determined that it is possible to detect the current value for diagnosing whether or not
On the other hand, when it is determined that the absolute value of the load fluctuation in the first phase power line is less than the first load fluctuation determination value and the first load fluctuation determination condition is satisfied, the second current detection unit performs the second current detection unit. The diagnostic apparatus according to claim 1, wherein it is determined that a current value for diagnosing whether or not is normal can be detected. The first load fluctuation determination value is set within the range of load fluctuation due to the power consumed by the second phase load, and the second load fluctuation determination value is a load due to the power consumed by the first phase load. The diagnostic device according to claim 2, which is set within a range of fluctuation. The diagnostic approval / disapproval determination unit
When the second load fluctuation determination condition is not satisfied, it is determined whether or not the absolute value of the load fluctuation in the first phase power line satisfies the first load fluctuation determination condition, and the current value by the second current detection unit is determined. Determine if detection is possible,
On the other hand, when the first load fluctuation determination condition is not satisfied, it is determined whether or not the absolute value of the load fluctuation in the second phase power line satisfies the second load fluctuation determination condition, and the first current detection unit determines. The diagnostic device according to claim 2 or 3, which determines whether or not the current value can be detected. The diagnostic approval / disapproval determination unit
When the first load fluctuation determination condition is not satisfied, the first load fluctuation determination value is extended within the range of load fluctuation due to the power consumption of the second phase load.
On the other hand, if the second load fluctuation determination condition is not satisfied, the second load fluctuation determination value is extended within the range of the load fluctuation due to the power consumption of the first phase load, according to any one of claims 2 to 4. Diagnostic device according to. When the diagnostic availability determination unit determines that the current value cannot be detected by the current detection unit because the load fluctuation determination condition is not satisfied, the system power supply notifies the third load to suppress the supply of electric power. The diagnostic device according to any one of claims 1 to 5, further comprising a notification unit. When the diagnosis possibility determination unit determines that the current value can be detected by the first current detection unit, the first phase load is connected to the first phase power line to receive power from the system power supply. The second phase load is controlled to the first phase load state in which the second phase load is disconnected from the second phase power line, while the current value by the second current detection unit is controlled by the diagnosis possibility determination unit. When it is determined that the first phase load can be detected, the second phase load is connected to the second phase power line so that power from the system power supply can be received, and the first phase load is the first phase load. A phase load control unit that controls the first-phase power line and the second-phase load state, which is a disconnected state,
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. A claim including a diagnostic unit that diagnoses whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition. Item 6. The diagnostic apparatus according to any one of Items 1 to 6. The diagnostic approval / disapproval determination unit
When the load fluctuation determination condition is not satisfied, the start-up process necessary for enabling the distributed power generation device to generate power is performed, and the load fluctuation determination condition is set before the distributed power generation device starts power generation. The diagnostic device according to any one of claims 1 to 7, which completes the determination and the determination of whether or not the current value can be detected. The diagnostic approval / disapproval determination unit
During power generation by the distributed power generation device, there is a possibility that the maintenance time is approaching and the power generation is stopped, or there is a possibility that the load fluctuation in the power line is smaller than in other time zones and the power generation is stopped. The diagnostic device according to any one of claims 1 to 7, wherein in the case of a timing including the above, the load fluctuation determination condition is determined and whether or not the current value can be detected is determined in the idling state. The diagnostic approval / disapproval determination unit
When the distributed power generation device is stopped during power generation by the distributed power generation device, it is possible to determine the load fluctuation determination condition and detect the current value within a predetermined time after the start of the stop processing. The diagnostic device according to any one of claims 1 to 7, which determines whether or not the device is used. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first phase. A load including a first phase load and a third load which is optionally connected to the first phase power line and the second phase power line and is a load different from the first phase load and the second phase load.
The diagnostic device according to any one of claims 1 to 10.
A distributed power generation system. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic method for diagnosing whether the current detector is normal or not.
It is determined whether or not the load fluctuation determination condition in which the absolute value of the load fluctuation in the power line is less than the predetermined load fluctuation determination value is satisfied, and when the load fluctuation determination condition is satisfied, the current detection unit performs the current detection unit. A diagnostic method comprising the step of determining that a current value can be detected to diagnose whether is normal or not. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic device that diagnoses whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control unit that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic unit that diagnoses whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
When the first diagnostic condition is not satisfied in the first phase load state, the phase load control unit switches to the second phase load state, and the diagnostic unit switches to the second phase load state after switching. Based on whether or not the diagnostic conditions are satisfied, it is diagnosed whether or not the second current detection unit is normal, and
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the phase load control unit switches to the first phase load state, and the diagnostic unit switches to the first phase load state after switching. 1 A diagnostic device that diagnoses whether or not the first current detection unit is normal based on whether or not the diagnostic conditions are satisfied. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic device that diagnoses whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control unit that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic unit that diagnoses whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
The diagnostic unit
When the first diagnostic condition is not satisfied in the first phase load state, the first diagnostic condition is extended within the range of load fluctuation due to the power consumption of the first phase load.
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the diagnostic device extends the second diagnostic condition within the range of load fluctuation due to the power consumption of the second phase load. The first diagnostic condition is set based on the load fluctuation due to the power consumed by the first phase load, and the second diagnostic condition is set based on the load fluctuation due to the power consumed by the second phase load. The diagnostic apparatus according to claim 13 or 14. At least one of the cases where the diagnostic unit determines that the first diagnostic condition is not satisfied in the first phase load state and the case where the second diagnostic condition is not satisfied in the second phase load state. The diagnostic apparatus according to any one of claims 13 to 15, further comprising a notification unit that notifies so as to suppress the supply of electric power from the system power supply to the third load in the case of. The diagnostic unit
When at least one of the first diagnostic condition and the second diagnostic condition is not satisfied, the start-up process necessary for enabling power generation by the distributed power generation device is performed, and the distributed power generation device generates power. The diagnostic apparatus according to any one of claims 13 to 16, wherein the determination of the first diagnostic condition and the second diagnostic condition is completed before starting. The diagnostic unit
When there is a possibility that the maintenance time is approaching and the power generation is stopped during the power generation by the distributed power generation device, or when the load fluctuation in the power line is less than in other time zones and the power generation may be stopped. The diagnostic apparatus according to any one of claims 13 to 16, wherein in the case of a timing including, the determination of the first diagnostic condition and the determination of the second diagnostic condition are performed in an idling state. The diagnostic unit
When the distributed power generation device is stopped during power generation by the distributed power generation device, the determination of the first diagnostic condition and the determination of the second diagnostic condition are performed within a predetermined time after the start of the stop processing. The diagnostic device according to any one of claims 13 to 16, which makes a determination. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first phase. A load including a first phase load and a third load which is optionally connected to the first phase power line and the second phase power line and is a load different from the first phase load and the second phase load.
The diagnostic device according to any one of claims 13 to 19.
Distributed power generation system with. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic method for diagnosing whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control step that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic step for diagnosing whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
When the first diagnostic condition is not satisfied in the first phase load state, the phase load control step switches to the second phase load state, and in the diagnostic step, the second phase load state after switching is performed. Based on whether or not the diagnostic conditions are satisfied, it is diagnosed whether or not the second current detection unit is normal, and
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the phase load control step switches to the first phase load state, and in the diagnostic step, the first phase load state after switching is the first. (1) A diagnostic method for diagnosing whether or not the first current detection unit is normal based on whether or not the diagnostic conditions are satisfied. A distributed power generator connected to a grid power supply via a power line including a first phase power line, a neutral line, and a second phase power line.
A current detection unit including a first current detection unit connected to the first phase power line and a second current detection unit connected to the second phase power line.
A first-phase load that can be selectively connected to and disconnected from the first-phase power line, a second-phase load that can be selectively connected to and disconnected from the second-phase power line, and the first-phase load. The said in a distributed power generation system including a load including a first phase load and a third load which is arbitrarily connected to the second phase power line and is a load different from the first phase load and the second phase load. It is a diagnostic method for diagnosing whether the current detector is normal or not.
The first phase load is connected to the first phase power line so that power from the system power supply can be received, and the second phase load is disconnected from the second phase power line. The phase load state and the second phase load are connected to the second phase power line so that power from the system power supply can be received, and the first phase load is disconnected from the first phase power line. A phase load control step that switches between the second phase load state, which is the state, and
The first current value and the second current value detected by the first current detection unit and the second current detection unit, respectively, or the load fluctuation corresponding to these current values in the first phase load state satisfy the first diagnostic condition. Whether or not the first current detection unit is normal is diagnosed based on whether or not the first current detection unit is normal, while the first current detected by each of the first current detection unit and the second current detection unit in the second phase load state. It is provided with a diagnostic step for diagnosing whether or not the second current detection unit is normal based on whether or not the value and the second current value or the load fluctuation corresponding to these current values satisfy the second diagnostic condition.
In the diagnostic step
When the first diagnostic condition is not satisfied in the first phase load state, the first diagnostic condition is extended within the range of load fluctuation due to the power consumption of the first phase load.
On the other hand, when the second diagnostic condition is not satisfied in the second phase load state, the diagnostic method extends the second diagnostic condition within the range of load fluctuation due to the power consumption of the second phase load.

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