JP2022052956A - Solitary operation detection sensor, solitary operation detection device, analyzer, and solitary operation detection method - Google Patents

Abstract

To provide an isolation detection sensor that does not induce a voltage flicker phenomenon.SOLUTION: An isolation detection sensor 3 includes a frequency detection unit 31 that detects the frequency f of an output voltage of a power conditioner 1, a first determination unit 32 that determines whether the frequency f matches a first determination condition, a second determination unit 33 that determines whether a second determination condition is met, and a third determination unit 34 that determines whether a third determination condition is met. The first determination condition is a condition for determining a change in the frequency f caused by the injection of the invalid power only by a new power source B2 arranged in a distribution system C, and the second determination condition is a condition for determining a change in the frequency f caused by the injection of an active signal only a conventional power supply B1 arranged in the distribution system C, and the third determination condition is a condition for determining the change in frequency f caused by the injection of the active signal by the new power supply B2 and the conventional power supply B1 arranged in the distribution system C.SELECTED DRAWING: Figure 1

Description

The present invention relates to a solitary operation detection sensor, a solitary operation detection device, an analyzer, and a solitary operation detection method.

When connecting a distributed power source to the power system, the power conditioner must be equipped with a solitary operation detector to prevent solitary operation. Independent operation means that when a distribution system to which a distributed power source is connected is disconnected from the power system, the distributed power source continues to supply power to the load of the distribution system. When the isolated operation detection device detects the isolated operation, the distributed power source is disconnected from the distribution system to stop the supply of power from the distributed power source to the load. There are two types of detection methods for solitary operation, a passive method and an active method, and various detection methods have been developed.

In the grid interconnection regulations (JEAC 9701-2016), frequency shift method, slip mode frequency shift method, reactive power fluctuation method, QC mode frequency shift method, etc. are permitted as the detection method of the active method of independent operation. These methods are called conventional active methods. According to the grid interconnection regulations, the conventional active-type isolated operation detector is 0.5 seconds or more and 1 second or less (in the case of interconnection with a low-voltage distribution line) when a power failure occurs and the isolated operation state is established. It is stipulated that the power conditioner should be separated from the distribution system. Further, in the grid interconnection regulation, the frequency feedback method with step injection is recognized as a method in which the detection is faster than the conventional active method. This method is called a new type active method. In the grid interconnection regulations, the new active type independent operation detector is stipulated to instantly disconnect the power conditioner from the distribution system in the event of a power failure and the independent operation state. Is set to disconnect within 0.1 seconds or more and 0.2 seconds or less. In each of these methods, an active signal typified by reactive power is positively injected into the distribution system, and independent operation is detected according to a change in the detected frequency. Therefore, when a large number of distributed power sources are connected to the distribution system, a large amount of reactive power is injected into the distribution system. Also, the injection amount of reactive power is increased according to the frequency deviation. Therefore, when the system is disturbed, each distributed power source increases the injection amount of the reactive power, so that the system voltage vibrates and a voltage flicker phenomenon may occur.

As a measure to suppress the occurrence of the voltage flicker phenomenon, an isolated operation detection device capable of suppressing the injection amount of reactive power has been developed. For example, Patent Document 1 discloses a solitary operation detection device that suppresses an injection amount of reactive power when the possibility of solitary operation is low. Further, in Patent Document 2, independent operation is detected based on an integrated value obtained by alternately injecting lagging phase reactive power and leading phase reactive power and integrating the absolute value of the amount of change in the moving average value of the system frequency. By doing so, a solitary operation detection device capable of preventing erroneous detection and detection delay of solitary operation while reducing the injection amount of reactive power is disclosed.

Japanese Unexamined Patent Publication No. 2017-93020 Japanese Unexamined Patent Publication No. 2019-92328

However, the isolated operation detection device disclosed in Patent Documents 1 and 2 suppresses the injection amount, but injects the reactive power. Therefore, when a power conditioner equipped with these isolated operation detection devices is newly connected to the distribution system, the reactive power injected into the distribution system increases. Therefore, even when such a power conditioner is connected to a distribution system to which a large number of power conditioners equipped with a stand-alone operation detection device are already connected, a voltage flicker phenomenon is induced.

The present invention has been conceived under the above circumstances, and is to provide a solitary operation detection sensor, a solitary operation detection device, an analyzer, and a solitary operation detection method that do not induce a voltage flicker phenomenon. I am aiming.

In order to solve the above problems, the following technical means are taken in the present invention.

In the isolated operation detection sensor provided by the first aspect of the present invention, the detection unit that detects the electrical characteristics related to the output of the power conditioner and the detection value detected by the detection unit match the first determination condition. A first determination unit that determines whether or not the detection value matches the second determination condition, a second determination unit that determines whether or not the detection value matches the second determination condition, and whether or not the detection value matches the third determination condition. The first determination condition includes a third determination unit for determination, and the first determination condition is that only a new type of active type independent operation detection device arranged in the distribution system to which the power conditioner is connected can transmit invalid power to the distribution system. It is a condition for determining the change in the electrical characteristics caused by the injection, and the second determination condition is that only the conventional active type isolated operation detection device arranged in the distribution system has the distribution. It is a condition for determining the change in the electrical characteristics caused by injecting an active signal into the system, and the third determination condition is the independent operation detection of the new type active method arranged in the distribution system. It is characterized in that the device and the conventional active type isolated operation detection device are conditions for determining the change in the electrical characteristics caused by injecting an active signal into the distribution system.

The "electrical characteristics" include voltage, current, electric power (active power, reactive power), frequency and the like. It also includes the voltage, current, power, frequency, etc. of predetermined harmonic components. Further, the "detection value detected by the detection unit" includes not only the magnitudes of voltage, current, power, frequency, etc., but also deviation (amount of change from the reference) and rate of change. Further, the "active signal" is a signal to be injected into the distribution system when the independent operation detection device detects the independent operation by the active method, and includes, for example, reactive power, active power, and the like.

In a preferred embodiment of the present invention, the first determination condition is that the rate of change of the detected value changes from the first time to the second time after the detected value starts to change, and then the third. The change rate did not change before the 4th hour after the time, and the second determination condition was that the change rate changed from the 5th hour to the 6th hour after the detection value started to change. After that, the rate of change changed from the 7th hour to the 8th hour, and the third determination condition was that the detected value started to change from the 9th hour to the 10th hour. The rate of change changed, and further changed from the 11th hour to before the 12th hour.

In a preferred embodiment of the present invention, the detection unit detects the frequency of the output voltage of the power conditioner as the detection value.

In a preferred embodiment of the present invention, the detection unit further detects a second detection value different from the detection value, and the first determination unit matches the detection value with the first determination condition. Further, it is determined whether or not the second detection value matches the fourth determination condition, and the second determination unit determines whether the detection value matches the second determination condition and the second determination condition. It is determined whether or not the detected value matches the fifth determination condition, and the third determination unit determines that the detection value matches the third determination condition and the second detection value is the sixth determination condition. Judge whether or not the match is met.

Whether the isolated operation detection device provided by the second aspect of the present invention determines that the isolated operation detection sensor provided by the first aspect of the present invention matches the first determination unit, or the second aspect thereof. It is characterized by including a determination unit for determining that the unit is in an independent operation state when it is determined that the determination units match or when the third determination unit determines that they match.

The analyzer provided by the third aspect of the present invention is the isolated operation detection sensor provided by the first aspect of the present invention, the determination result by the first determination unit, and the determination result by the second determination unit. And, based on the determination result by the third determination unit, the analysis unit that analyzes the arrangement state of the conventional active type independent operation detection device and the new type active type independent operation detection device in the distribution system. It is characterized by having and.

In the isolated operation detection sensor provided by the fourth aspect of the present invention, whether or not the detection unit that detects the electrical characteristics related to the output of the power conditioner and the detection value detected by the detection unit match the determination conditions. The determination condition includes a determination unit for determining whether or not the power conditioner is connected, and only the new active type independent operation detection device arranged in the distribution system to which the power conditioner is connected injects invalid power into the distribution system. This is a condition for determining the change in the electrical characteristics caused by the above.

In the isolated operation detection sensor provided by the fifth aspect of the present invention, whether or not the detection unit that detects the electrical characteristics related to the output of the power conditioner and the detection value detected by the detection unit match the determination conditions. It is provided with a determination unit for determining whether or not the power conditioner is connected, and the determination condition is that only the conventional active type independent operation detection device arranged in the distribution system to which the power conditioner is connected injects invalid power into the distribution system. This is a condition for determining the change in the electrical characteristics caused by the above.

In the isolated operation detection sensor provided by the sixth aspect of the present invention, whether or not the detection unit that detects the electrical characteristics related to the output of the power conditioner and the detection value detected by the detection unit match the determination conditions. The determination condition includes a determination unit for determining whether or not the power conditioner is connected, and the determination condition is a new type active type independent operation detection device and a conventional active type independent operation detection device arranged in the distribution system to which the power conditioner is connected. Is a condition for determining the change in the electrical characteristics caused by injecting the ineffective power into the distribution system.

In the isolated operation detection method provided by the seventh aspect of the present invention, the detection step of detecting the electrical characteristics related to the output of the power conditioner and the detection value detected in the detection step match the first determination condition. A first determination step for determining whether or not the detected value matches the second determination condition, a second determination step for determining whether or not the detected value matches the second determination condition, and whether or not the detected value matches the third determination condition. When it is determined that the third determination step for determination and the first determination step match, whether it is determined that they match in the second determination step, or that they match in the third determination step, it is independent. The first determination condition is that only the new active type independent operation detection device arranged in the distribution system to which the power conditioner is connected has the determination step of determining that the power conditioner is in operation. It is a condition for determining the change in the electrical characteristics caused by injecting the ineffective power, and the second determination condition is only the conventional active type isolated operation detection device arranged in the distribution system. Is a condition for determining the change in the electrical characteristics caused by injecting an active signal into the distribution system, and the third determination condition is the new type of active system arranged in the distribution system. The feature is that the solitary operation detection device and the conventional active solitary operation detection device are conditions for determining the change in the electrical characteristics caused by injecting an active signal into the distribution system. do.

In the isolated operation detection method provided by the eighth aspect of the present invention, the detection step of detecting the electrical characteristics related to the output of the power conditioner and whether or not the detection values detected in the detection step match the determination conditions. It is provided with a determination step of determining whether or not the power is present, and a determination step of determining that the unit is in an independent operation state when it is determined in the determination step that the determination conditions are the same. Only the new active type independent operation detection device arranged in the system is a condition for determining the change in the electrical characteristics caused by injecting the ineffective power into the distribution system.

In the isolated operation detection method provided by the ninth aspect of the present invention, the detection step of detecting the electrical characteristics related to the output of the power conditioner and whether or not the detection values detected in the detection step match the determination conditions. The determination step includes a determination step of determining whether or not the power is present, and a determination step of determining that the unit is in an independent operation state when it is determined that the determination steps match. The determination condition is the power distribution to which the power conditioner is connected. Only the conventional active type independent operation detection device arranged in the system is a condition for determining the change in the electrical characteristics caused by injecting the active signal into the distribution system.

The isolated operation detection method provided by the tenth aspect of the present invention has a detection step of detecting electrical characteristics related to the output of a power conditioner and whether or not the detection values detected in the detection step match the determination conditions. The determination step includes a determination step of determining whether or not the power conditioner is the same, and a determination step of determining that the vehicle is in an independent operation state when it is determined that the determination steps match. The determination condition is the power distribution to which the power conditioner is connected. The new active type independent operation detection device and the conventional active type single operation detection device arranged in the system determine the change in the electrical characteristics caused by injecting an active signal into the distribution system. It is a condition for.

According to the present invention, the first to third determination units determine the change in electrical characteristics in the distribution system due to the injection of an active signal such as reactive power into the distribution system by another isolated operation detection device. Since the isolated operation detection sensor according to the present invention does not inject reactive power into the distribution system, it does not induce a voltage flicker phenomenon.

Other features and advantages of the invention will be more apparent by the detailed description given below with reference to the accompanying drawings.

It is a block diagram for demonstrating the power conditioner provided with the isolated operation detection apparatus which concerns on 1st Embodiment, and shows the whole structure of a power distribution system. It is a time chart showing the frequency change of the output voltage of the power conditioner, (a) shows the case where the distribution system to which only the new power supply is connected is in a power failure state, and (b) is the case where only the conventional power supply is connected. The case where the distributed distribution system is in a power failure state is shown, and (c) shows the case where the distribution system to which both the conventional power supply and the new power supply are connected is in a power failure state. It is a time chart which shows the frequency change of the output voltage of a power conditioner, and shows the case where a system disturbance occurs. This is an example of a flowchart for explaining the first determination process performed by the first determination unit. (A) is an example of a flowchart for explaining the second determination process performed by the second determination unit, and (b) is an example of a flowchart for explaining the third determination process performed by the third determination unit. It is a block diagram which shows the internal structure of the isolated operation detection apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the internal structure of the isolated operation detection apparatus which concerns on 3rd Embodiment. It is a block diagram for demonstrating the power conditioner provided with the analyzer which concerns on 4th Embodiment, and shows the whole structure of a power distribution system.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram for explaining a power conditioner including a stand-alone operation detection device according to the first embodiment, and shows an overall configuration of a power distribution system.

The power conditioner 1 converts the DC power output by the DC power source A into AC power and outputs it to the connected distribution system C. A distributed power source is a combination of the power conditioner 1 and the DC power source A. The distribution system C is a high-voltage distribution system, to which a load L, a conventional power supply B1 and a new power supply B2 are connected. The load L is a consumer who receives power supply. The conventional power source B1 is a distributed power source provided with a power conditioner having a conventional active type independent operation detection device. In this embodiment, a case where the independent operation detection device of the conventional power supply B1 detects the independent operation by the frequency shift method will be described as an example. The detection method of the independent operation detection device of the conventional power supply B1 is not limited. The new power source B2 is a distributed power source equipped with a power conditioner having a new type active type independent operation detection device. A plurality of loads L, a plurality of conventional power supplies B1 and a plurality of new power supplies B2 are connected to the distribution system C (and the low-voltage distribution system connected to the distribution system C via a transformer). , One by one as a representative. The distribution system C is connected to the power system via a circuit breaker. When an accident occurs in the power system, the circuit breaker is opened by a protective device provided on the power system side, and the distribution system C is disconnected from the power system (power failure state). As a result, the power conditioner 1 connected to the distribution system C separated from the power system is put into an independent operation state.

The DC power source A outputs DC power, and includes, for example, a solar cell. Solar cells generate DC power by converting solar energy into electrical energy. The DC power supply A outputs the generated DC power to the power conditioner 1. The DC power supply A is not limited to the one that generates DC power by a solar cell. For example, the DC power source A may be a fuel cell, a storage battery, or the like, or may be a device that converts AC power generated by a diesel engine generator, a wind turbine generator, or the like into DC power and outputs it. ..

The power conditioner 1 includes an inverter device 2, an independent operation detection device 3, a circuit breaker 4 for interconnection, and a voltage sensor 5. The power conditioner 1 is connected to the distribution system C via a circuit breaker 4 for interconnection.

The inverter device 2 converts the DC power input from the DC power supply A into AC power and outputs it. The inverter device 2 includes, for example, an inverter circuit, a filter circuit, and a control circuit (not shown). The inverter circuit converts DC power into AC power by switching on and off of a switching element (not shown) based on a PWM signal input from a control circuit. The filter circuit removes high frequency components due to switching. The control circuit controls the inverter circuit. The control circuit generates a PWM signal for controlling the output current of the inverter device 2 and outputs the PWM signal to the inverter circuit. When the gate block signal described later is input from the independent operation detection device 3, the control circuit stops the generation of the PWM signal. In this case, since the inverter circuit stops switching, the inverter device 2 stops the power conversion operation. The configuration of the inverter device 2 is not limited.

The interconnection circuit breaker 4 cuts off the connection between the power conditioner 1 and the distribution system C. The circuit breaker 4 for interconnection is normally closed, and the power conditioner 1 is connected to the distribution system C. However, when the open command described later is input from the independent operation detection device 3, the interconnection circuit breaker 4 is opened and the power conditioner 1 is disconnected from the distribution system C. As a result, the independent operation state of the power conditioner 1 is avoided.

The voltage sensor 5 detects the output voltage of the power conditioner 1 and inputs the detected voltage signal to the independent operation detection device 3. The voltage sensor 5 may also be used for controlling the inverter device 2. In this case, the voltage sensor 5 also inputs the detected voltage signal to the control circuit of the inverter device 2.

The solitary operation detection device 3 detects the solitary operation of the power conditioner 1. The solitary operation detection device 3 detects the solitary operation based on the voltage signal input from the voltage sensor 5, and when the solitary operation is detected, the power conditioner 1 is stopped and disconnected from the distribution system C. The independent operation detection device 3 includes a frequency detection unit 31, a first determination unit 32, a second determination unit 33, a third determination unit 34, a determination unit 35, and a stop processing unit 38.

The frequency detection unit 31 detects the frequency f of the output voltage of the power conditioner 1. The frequency detection unit 31 detects the frequency f based on the voltage signal input from the voltage sensor 5. The frequency detection unit 31 detects the frequency by, for example, a zero cross point counting method. The zero-cross point counting method is a method of measuring the time between points where the instantaneous value of the AC voltage intersects the zero level (zero cross point) and detecting the frequency from the reciprocal of the measured time. The frequency detection method of the frequency detection unit 31 is not limited. For example, the frequency detection unit 31 may detect the frequency using a multiplication type PLL (Phase Locked Loop). In the present embodiment, the frequency detection unit 31 calculates the average value of the detected frequencies for a predetermined time in order to eliminate minute fluctuations and detection errors, and outputs the calculated average value as the frequency f. The frequency detection unit 31 outputs the detected frequency f to the first determination unit 32, the second determination unit 33, and the third determination unit 34. The frequency detection unit 31 corresponds to the "detection unit" of the present invention, and the frequency f corresponds to the "detection value" of the present invention.

The first determination unit 32, the second determination unit 33, and the third determination unit 34 each determine whether or not the frequency f input from the frequency detection unit 31 matches the preset determination condition. When a solitary operation occurs, the solitary operation detection device of the conventional power supply B1 and the new power supply B2 connected to the distribution system C increases the injecting reactive power to the frequency of the voltage of the distribution system C (hereinafter, "system". The frequency is changed), and when the detected frequency exceeds the threshold value, the isolated operation is detected. The solitary operation detection device 3 detects the solitary operation by capturing the change pattern of the system frequency at this time. However, the time limit from the occurrence of a power failure to the disconnection specified in the grid interconnection regulations differs between the independent operation detection device of the conventional power supply B1 and the independent operation detection device of the new power supply B2. Therefore, the change pattern of the system frequency differs depending on whether or not the conventional power supply B1 and the new power supply B2 are connected to the distribution system C, respectively. In the first determination unit 32, a condition for determining whether or not the pattern is a change pattern of the system frequency when only the new power supply B2 is connected to the distribution system C is set as the first determination condition. In the second determination unit 33, a condition for determining whether or not the pattern is a change pattern of the system frequency when only the conventional power supply B1 is connected to the distribution system C is set as the second determination condition. .. In the third determination unit 34, a condition for determining whether or not the change pattern of the system frequency is obtained when both the new power supply B2 and the conventional power supply B1 are connected to the distribution system C is a third determination condition. Is set as.

FIG. 2 is a time chart showing changes in the frequency f of the output voltage when the distribution system C shown in FIG. 1 is in a power failure state and the power conditioner 1 is in an independent operation state. The horizontal axis shows the elapsed time after the power failure occurs in 0 seconds. The vertical axis indicates the frequency f. The vertical and horizontal axes of the waveform charts and time charts referred to in the present specification are appropriately enlarged or reduced for ease of understanding, and each waveform shown is also for ease of understanding. Simplified, or exaggerated or emphasized.

FIG. 2A shows a case where the conventional power supply B1 is not connected to the distribution system C and only the new power supply B2 is connected.

When a power failure occurs, the system frequency of the distribution system C changes slightly. The new power supply B2 catches the frequency change and injects the reactive power to raise or lower the system frequency. FIG. 2A shows a case where the system frequency rises. Note that FIGS. 2 (b), 2 (c) and 3 also show a case where the system frequency rises. The new power supply B2 is generally disconnected from the distribution system C by detecting independent operation within 0.1 seconds or more and 0.2 seconds after a power failure. Therefore, the reactive power is rapidly injected from the occurrence of the power failure, and the system frequency rises rapidly. Since the frequency f of the output voltage of the power conditioner 1 matches the system frequency, the frequency f rapidly rises from the occurrence of a power failure (see point a in FIG. 2A) as shown in FIG. 2A. ing. Further, since the new power supply B2 detects the independent operation within 0.2 seconds and stops the injection of the reactive power, the rate of change of the system frequency changes at this time. Therefore, as shown by the solid line in FIG. 2A, the frequency f turns downward during the elapsed time from the time T1 to the time T2 (see the point b in FIG. 2A). In the present embodiment, the time T1 is 0.1 seconds and the time T2 is 0.2 seconds, but the time T1 and the time T2 are not limited. It is set as appropriate based on the results of experiments, simulations, or on-site surveys. As shown by the broken line in FIG. 2A, the frequency f changes variously, and may continue to rise instead of falling from the point b. However, when any of the new power sources B2 stops the injection of the reactive power, the rate of change Δf of the frequency f becomes smaller. Then, by 0.2 seconds, all the new power sources B2 stop injecting the reactive power, and then the frequency f returns to the frequency slightly changed due to the occurrence of the power failure (the frequency before the injecting the reactive power). ..

FIG. 2B shows a case where the new power supply B2 is not connected to the distribution system C and only the conventional power supply B1 is connected.

When a power failure occurs, the system frequency of the distribution system C changes slightly. The conventional power supply B1 catches the frequency change and injects the reactive power to raise or lower the system frequency. The conventional power supply B1 is disconnected from the distribution system C by detecting independent operation within 0.5 seconds or more and 1 second after a power failure. Therefore, the reactive power is injected from the occurrence of the power failure, and the system frequency rises. Since the injection of reactive power by the conventional power supply B1 is slower than that of the new power supply B2, the system frequency also rises relatively slowly. Therefore, as shown in FIG. 2B, the frequency f slowly rises from the occurrence of a power failure (see point a in FIG. 2B). Further, since the conventional power supply B1 detects the independent operation within 1 second and stops the injection of the reactive power, the rate of change of the system frequency changes at this time. Therefore, as shown by the solid line in FIG. 2 (b), the frequency f turns downward during the elapsed time from the time T3 to the time T4 (see the point b in FIG. 2 (b)). In the present embodiment, the time T3 is 0.5 seconds and the time T4 is 1 second, but the time T3 and the time T4 are not limited. It is set as appropriate based on the results of experiments, simulations, or on-site surveys. As shown by the broken line in FIG. 2B, the frequency f changes variously, and may continue to rise instead of falling from the point b. However, when any of the conventional power supplies B1 stops the injection of the reactive power, the rate of change Δf of the frequency f becomes small. Then, by 1 second, all the conventional power supplies B1 stop injecting the reactive power, and then the frequency f returns to the frequency slightly changed due to the occurrence of the power failure (the frequency before the injecting the reactive power).

FIG. 2C shows a case where both the conventional power supply B1 and the new power supply B2 are connected to the distribution system C (see FIG. 1).

When a power failure occurs, the system frequency of the distribution system C changes slightly. Capturing the frequency change, the new power supply B2 rapidly injects the reactive power, and the conventional power supply B1 slowly injects the reactive power. As a result, the system frequency rises or falls rapidly. Therefore, as shown in FIG. 2 (c), the frequency f rises rapidly from the occurrence of a power failure (see point a in FIG. 2 (c)). Since the new power supply B2 detects the independent operation within 0.2 seconds and stops the injection of the reactive power, the rate of change of the system frequency becomes small at this time. However, since the conventional power supply B1 continues to inject reactive power, the rate of decrease in the rate of change is limited. Therefore, as shown by the solid line in FIG. 2 (c), the rate of change Δf of the frequency f is small during the elapsed time from the time T1 to the time T2 (see the point b in FIG. 2 (c)). .. Then, since the conventional power supply B1 detects the independent operation within 1 second and stops the injection of the reactive power, the rate of change of the system frequency also changes at this time. Therefore, as shown by the solid line in FIG. 2 (c), the frequency f turns downward during the elapsed time from the time T3 to the time T4 (see the point c in FIG. 2 (c)). As shown by the broken line in FIG. 2 (c), the frequency f changes variously, and may continue to rise instead of falling from the point c. However, when any of the conventional power supplies B1 stops the injection of the reactive power, the rate of change Δf of the frequency f becomes small. Then, by 1 second, all the conventional power supplies B1 stop injecting the reactive power, and then the frequency f returns to the frequency slightly changed due to the occurrence of the power failure (the frequency before the injecting the reactive power).

The first determination unit 32 determines whether or not the change pattern of the frequency f input from the frequency detection unit 31 is the change pattern shown in FIG. 2A. Specifically, the first determination condition set in the first determination unit 32 is that the rate of change Δf changes after the time T1 and before the time T2 after the frequency f starts to change, and then the time after the time T3. The rate of change Δf did not change before T4. The rate of change Δf is the amount of change in the frequency f per unit time. It is determined that the frequency f has started to change, for example, when it exceeds a range (f ₀ − f ₁ ≦ f ≦ f ₀ + f ₁ ) set around the reference value f ₀ of the frequency f. An appropriate value of f ₁ is set based on an experiment, a simulation result, a field survey result, or the like. Further, the rate of change Δf is determined to have changed when, for example, the range (x−Δx ≦ Δf ≦ x + Δx) set around the immediately preceding rate of change x is exceeded. An appropriate value of Δx is set based on an experiment, a simulation result, a field survey result, or the like. The method for determining the start of change in frequency f is not limited. Further, the method for determining the change in the rate of change Δf is not limited. When the first determination unit 32 determines that the frequency f matches the first determination condition, the first determination unit 32 outputs, for example, a first determination signal which is a high level signal to the determination unit 35. "Time T1" corresponds to the "first time" of the present invention, "time T2" corresponds to the "second time" of the present invention, and "time T3" corresponds to the "third time" of the present invention. , "Time T4" corresponds to the "fourth time" of the present invention.

FIG. 4 is an example of a flowchart for explaining the first determination process performed by the first determination unit 32. The first determination process is a process of determining whether or not the change in frequency f matches the first determination condition. The first determination process is executed when the inverter device 2 starts the power conversion operation while the power conditioner 1 is connected to the distribution system C.

First, the frequency f detected by the frequency detection unit 31 is acquired (S1), and it is determined whether or not the frequency f has started to change (S2). Specifically, it is determined whether or not the frequency f falls within the range (f ₀ −f ₁ ≦ f ≦ f ₀ + f ₁ ) set around the reference value f ₀ . If it is within the range (S2: YES), it is determined that there is no change in the frequency f, the process returns to step S1, and the processes of steps S1 and S2 are repeated. On the other hand, when the range exceeds the range (S2: NO), it is determined that the frequency f has started to change, the rate of change Δf at this time is calculated (S3), and the rate of change x1 is set (S4). Time T is started (S5).

Next, the frequency f is acquired (S6), the rate of change Δf is calculated (S7), and it is determined whether or not the rate of change Δf has changed (S8). Specifically, it is determined whether or not the rate of change Δf falls within the range (x1-Δx ≦ Δf ≦ x1 + Δx) set around the rate of change x1 when the frequency f starts to change. If it is within the range (S8: YES), it is determined that the rate of change Δf has not changed, the process returns to step S6, and the processes of steps S6 to S8 are repeated. On the other hand, when the range exceeds the range (S8: NO), it is determined that the rate of change Δf has changed, and the process proceeds to step S9.

Next, it is determined whether or not the elapsed time T at this time is between the time T1 and the time T2 (S9). If the elapsed time T is not between the time T1 and the time T2 (S9: NO), it is assumed that the first condition is not met, and the first determination process ends. On the other hand, when the elapsed time T is between the time T1 and the time T2 (S9: YES), the frequency f is acquired (S10), the rate of change Δf is calculated (S11), and the rate of change x2 is set. (S12). Next, it is determined whether or not the elapsed time T is the time T3 or more (S13). If the elapsed time T is less than the time T3 (S13: NO), the process returns to step S10, the processes of steps S10 to S13 are repeated, and if the elapsed time T is the time T3 or more (S13: YES), the process proceeds to step S14. .. That is, the rate of change x2 is updated to the latest rate of change Δf while waiting until the elapsed time T reaches the time T3.

Next, the frequency f is acquired (S14), the rate of change Δf is calculated (S15), and it is determined whether or not the rate of change Δf has changed (S16). Specifically, it is determined whether or not the rate of change Δf is within the range (x2-Δx≤Δf≤x2 + Δx) set around the rate of change x2 immediately before the elapsed time T becomes the time T3. When it is within the range (S16: YES), it is determined that the rate of change Δf has not changed, and it is determined whether or not the elapsed time T is the time T4 or more (S17). If the elapsed time T is less than the time T4 (S17: NO), the process returns to step S14 and the processes of steps S14 to S17 are repeated. In step S16, when the range is exceeded (S16: NO), it is determined that the rate of change Δf has changed even between the time T3 and the time T4, and it is determined that the first condition is not met, and the first determination process ends. do. On the other hand, in step S17, when the elapsed time T is the time T4 or more (S17: YES), it is determined that the rate of change Δf did not change between the time T3 and the time T4, and it is assumed that the first condition is met. 1 The determination signal is output (S18), and the first determination process ends.

The process shown in the flowchart of FIG. 4 is an example, and the first determination process performed by the first determination unit 32 is not limited to the above-mentioned one.

The second determination unit 33 determines whether or not the change pattern of the frequency f input from the frequency detection unit 31 is the change pattern shown in FIG. 2B. Specifically, the second determination condition set in the second determination unit 33 is that the rate of change Δf does not change after the time T1 and before the time T2 after the frequency f starts to change, and then after the time T3. The rate of change Δf changed before the time T4. When the second determination unit 33 determines that the frequency f matches the second determination condition, the second determination unit 33 outputs, for example, a second determination signal, which is a high level signal, to the determination unit 35. "Time T1" corresponds to "fifth time" of the present invention, "time T2" corresponds to "sixth time" of the present invention, and "time T3" corresponds to "seventh time" of the present invention. , "Time T4" corresponds to the "eighth time" of the present invention. In the present embodiment, the case where the time T1 to T4 of the second determination unit 33 is the same time as the time T1 to T4 of the first determination unit 32 is described, but the second determination unit 33 describes the case. , A time different from that of the first determination unit 32 may be set.

FIG. 5A is an example of a flowchart for explaining the second determination process performed by the second determination unit 33. The second determination process is a process of determining whether or not the change in frequency f matches the second determination condition. The second determination process is executed when the inverter device 2 starts the power conversion operation while the power conditioner 1 is connected to the distribution system C.

Since steps S1 to S8 are the same as the first determination process shown in FIG. 4, the description thereof will be omitted. In step S8, it is determined that the rate of change Δf has changed (S8: NO), and it is determined whether or not the elapsed time T at this time is between the time T3 and the time T4 (S21). If the elapsed time T is not between the time T3 and the time T4 (S21: NO), it is assumed that the second condition is not met, and the second determination process ends. On the other hand, when the elapsed time T is between the time T3 and the time T4 (S21: YES), it is determined that the second condition is satisfied, the second determination signal is output (S22), and the second determination process is performed. Is finished.

The process shown in the flowchart of FIG. 5A is an example, and the second determination process performed by the second determination unit 33 is not limited to the above-mentioned process.

The third determination unit 34 determines whether or not the change pattern of the frequency f input from the frequency detection unit 31 is the change pattern shown in FIG. 2 (c). Specifically, the third determination condition set in the third determination unit 34 is that the rate of change Δf changes after the time T1 and before the time T2 after the frequency f starts to change, and further, the time after the time T3. The rate of change Δf changed even before T4. When the third determination unit 34 determines that the frequency f matches the third determination condition, the third determination unit 34 outputs, for example, a third determination signal, which is a high level signal, to the determination unit 35. "Time T1" corresponds to "9th hour" of the present invention, "time T2" corresponds to "10th hour" of the present invention, and "time T3" corresponds to "11th hour" of the present invention. , "Time T4" corresponds to "12th hour" of the present invention. In the present embodiment, the case where the time T1 to T4 of the third determination unit 34 is the same time as the time T1 to T4 of the first determination unit 32, respectively, is described, but the third determination unit 34 describes. A time different from that of the first determination unit 32 may be set.

FIG. 5B is an example of a flowchart for explaining the third determination process performed by the third determination unit 34. The third determination process is a process for determining whether or not the change in frequency f matches the third determination condition. The third determination process is executed when the inverter device 2 starts the power conversion operation while the power conditioner 1 is connected to the distribution system C.

Since steps S1 to S17 are the same as the first determination process shown in FIG. 4, the description thereof will be omitted. In the third determination process, in step S17, when the elapsed time T is the time T4 or more (S17: YES), it is determined that the rate of change Δf did not change between the time T3 and the time T4, and the third condition is met. If not done, the third determination process ends. On the other hand, in step S16, when the range is exceeded (S16: NO), it is determined that the rate of change Δf has changed even between the time T3 and the time T4, and the third determination signal is output assuming that the third condition is met. (S31), the third determination process ends.

The process shown in the flowchart of FIG. 5B is an example, and the third determination process performed by the third determination unit 34 is not limited to the above-mentioned one.

The first determination condition set in the first determination unit 32, the second determination condition set in the second determination unit 33, and the third determination condition set in the third determination unit 34 are limited to the above-mentioned conditions. Not done. The first determination condition may be any condition as long as it can detect the change pattern shown in FIG. 2A, and it may be a condition that it can be determined that the independent operation has occurred when only the new power supply B2 is connected to the distribution system C. Just do it. The second determination condition may be a condition that can detect the change pattern shown in FIG. 2B, and is a condition that it can be determined that the independent operation has occurred when only the conventional power supply B1 is connected to the distribution system C. All you need is. The third determination condition may be any condition as long as the change pattern shown in FIG. 2C can be detected, and the independent operation occurs when both the conventional power supply B1 and the new power supply B2 are connected to the distribution system C. Any condition can be used as long as it can be concluded. For example, the first to third determination conditions are further added with the range of the rate of change x1 from the occurrence of the power failure to the first change of the rate of change Δf (from point a to point b shown in each figure of FIG. 2). You may.

FIG. 3 is a time chart showing a change in the frequency f of the output voltage when the distribution system C is not in a power failure state but a system disturbance occurs. The horizontal axis shows the elapsed time after the occurrence of the system disturbance is 0 seconds. The vertical axis indicates the frequency f. FIG. 3 shows a case where the conventional power supply B1 and the new power supply B2 are connected to the distribution system C (see FIG. 1). The same applies to the case where only the conventional power supply B1 is connected to the distribution system C and the case where only the new power supply B2 is connected.

Even when system disturbance occurs, the system frequency of the distribution system C changes slightly. The conventional power supply B1 and the new power supply B2 catch the frequency change and inject the reactive power, but since there is no power failure, the frequency f does not rise. Therefore, as shown by the solid line in FIG. 3, the frequency f does not change much from the occurrence of system disturbance (see point a in FIG. 3). Since the change of the frequency f is small, the frequency f does not exceed the range (f ₀ − f ₁ ≦ f ≦ f ₀ + f ₁ ) set around the reference value f ₀ , and it is not determined that the change has started. Since none of the first to third determination conditions is met, independent operation is not detected. Further, as shown by the broken line in FIG. 3, even when the frequency f changes so as to exceed the range, the injection of the reactive power by the conventional power supply B1 and the new power supply B2 does not affect the change in the frequency f, so that the frequency f is not affected. Immediately returns to the reference value f ₀ . In this case, since the frequency f has turned downward by the time the elapsed time reaches the time T1 (see point b in FIG. 3), it does not match any of the first to third determination conditions, and the independent operation is detected. Not done.

The determination unit 35 determines whether or not it is in the independent operation state based on the determination results of the first determination unit 32, the second determination unit 33, and the third determination unit 34. The determination unit 35 generates a logical sum signal of the signal input from the first determination unit 32, the signal input from the second determination unit 33, and the signal input from the third determination unit 34, and the stop processing unit 38. Output to. Therefore, the determination unit 35 receives the first determination signal (high level signal) from the first determination unit 32, or the second determination signal (high level signal) from the second determination unit 33. 3 When a third determination signal (high level signal) is input from the determination unit 34, the independent operation detection signal, which is a high level signal, is output to the stop processing unit 38, assuming that the unit is in an independent operation state.

The stop processing unit 38 performs stop processing of the power conditioner 1 when an independent operation detection signal is input from the determination unit 35. Specifically, the stop processing unit 38 outputs a gate block signal to the inverter device 2 to stop the power conversion operation of the inverter device 2. Further, the stop processing unit 38 outputs an opening command to the interconnection circuit breaker 4 to disconnect the power conditioner 1 from the distribution system C.

The grid interconnection regulations stipulate that the power conditioner connected to the high-voltage distribution system should be disconnected within 3 seconds when it becomes a stand-alone operation state. The first determination unit 32, the second determination unit 33, and the third determination unit 34 make determinations by the time T4 (for example, 1 second) elapses after the frequency f starts to change in the independent operation state. be able to. As soon as the independent operation is detected by the determination, the stop processing unit 38 performs the stop processing of the power conditioner 1. Therefore, the independent operation detection device 3 can disconnect the power conditioner 1 from the distribution system C within 3 seconds if the new power supply B2 or the conventional power supply B1 is connected to the distribution system C.

The independent operation detection device 3 may be realized as an analog circuit or a digital circuit. Further, the computer may be made to function as the independent operation detection device 3 by designing the processing performed by each unit by a program and executing the program. Further, the program may be recorded on a recording medium and read by a computer. Among the independent operation detection devices 3, the combination of the frequency detection unit 31, the first determination unit 32, the second determination unit 33, and the third determination unit 34 corresponds to the "independent operation detection sensor" of the present invention.

Next, the operation and effect of the isolated operation detection device 3 according to the present embodiment will be described.

According to the present embodiment, the first determination unit 32, the second determination unit 33, and the third determination unit 34 determine the change in the system frequency due to the other independent operation detection device injecting the reactive power into the distribution system C. do. Then, the determination unit 35 determines whether or not it is in the independent operation state based on the determination results of the first determination unit 32, the second determination unit 33, and the third determination unit 34. Since the isolated operation detection device 3 does not inject the reactive power into the distribution system C, it does not induce the voltage flicker phenomenon. That is, in the distribution system C in which the voltage flicker phenomenon does not occur, the voltage flicker phenomenon does not occur even when a large number of power conditioners 1 including the independent operation detection device 3 are added. Further, even when a large number of power conditioners 1 provided with the independent operation detection device 3 are added to the distribution system C in which the voltage flicker phenomenon occurs, the voltage flicker phenomenon is not promoted.

Further, according to the present embodiment, the isolated operation detecting device 3 detects the isolated operation based on the frequency f of the output voltage of the power conditioner 1. The solitary operation detection device of the conventional power supply B1 and the new power supply B2 further changes the system frequency by injecting the reactive power corresponding to the frequency deviation in order to detect the solitary operation. Therefore, the isolated operation detecting device 3 can appropriately detect the isolated operation.

Further, according to the present embodiment, the first determination condition is that the rate of change Δf changes after the time T1 and before the time T2 after the frequency f starts to change, and then the rate of change Δf changes after the time T3 and before the time T4. It didn't change. Therefore, the first determination unit 32 can appropriately determine that the independent operation has occurred when only the new power supply B2 is connected to the distribution system C. The second determination condition is that the rate of change Δf does not change after the time T1 and before the time T2 after the frequency f starts to change, and then the rate of change Δf changes after the time T3 and before the time T4. Therefore, the second determination unit 33 can appropriately determine that the independent operation has occurred when only the conventional power supply B1 is connected to the distribution system C. The third determination condition is that the rate of change Δf changes after the time T1 and before the time T2 after the frequency f starts to change, and further, the rate of change Δf changes after the time T3 and before the time T4. Therefore, the third determination unit 34 can appropriately determine that the independent operation has occurred when both the new power supply B2 and the conventional power supply B1 are connected to the distribution system C. As a result, the isolated operation detecting device 3 can appropriately detect the isolated operation when either the new power source B2 or the conventional power source B1 is connected to the distribution system C.

In the present embodiment, the case where the independent operation detection device 3 detects the independent operation based on the frequency f of the output voltage of the power conditioner 1 detected by the frequency detection unit 31 has been described. Not limited. The isolated operation detection device 3 may use the frequency of the output current or the output power of the power conditioner 1. Further, the isolated operation detecting device 3 may detect the isolated operation based on electrical characteristics such as voltage, current, and electric power (active power, reactive power) output by the power conditioner 1. Further, the isolated operation may be detected based on the voltage, current, power, frequency, and the like of a predetermined harmonic component such as the third order, the fifth order, and the seventh order. Further, the detection values used by the first determination unit 32, the second determination unit 33, and the third determination unit 34 are not limited to the detection values obtained by detecting the magnitudes of voltage, current, power, frequency, and the like, and deviations ( The amount of change from the standard) and the rate of change may be used. The first determination condition set in the first determination unit 32, the second determination condition set in the second determination unit 33, and the third determination condition set in the third determination unit 34 depend on the detection value to be used. It is set appropriately.

[Second Embodiment]
FIG. 6 is a block diagram showing an internal configuration of the isolated operation detection device according to the second embodiment. In the figure, the same or similar elements as those of the isolated operation detection device 3 (see FIG. 1) according to the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

The independent operation detection device 3a according to the present embodiment is the independent operation detection device 3 in that the first determination unit 32, the second determination unit 33, and the third determination unit 34 make a determination using two types of detection values. different.

The isolated operation detection device 3a further includes a voltage detection unit 39. The voltage detection unit 39 detects the effective voltage value v of the output voltage of the power conditioner 1. The voltage detection unit 39 detects the effective voltage value v based on the voltage signal input from the voltage sensor 5. The voltage detection unit 39 outputs the detected voltage effective value v to the first determination unit 32, the second determination unit 33, and the third determination unit 34. In the present embodiment, the voltage detection unit 39 also corresponds to the “detection unit” of the present invention, and the effective voltage value v corresponds to the “second detection value” of the present invention. The voltage detection unit 39 may detect the maximum value or the average value of the voltage.

The first determination unit 32 according to the second embodiment makes a determination based on the frequency f input from the frequency detection unit 31 and the voltage effective value v input from the voltage detection unit 39. The first determination unit 32 includes a frequency determination unit 321, a voltage determination unit 322, and an AND unit 323. The frequency determination unit 321 is a functional block similar to the first determination unit 32 according to the first embodiment, and determines whether or not the frequency f input from the frequency detection unit 31 matches the first determination condition. When the frequency determination unit 321 determines that the frequency f matches the first determination condition, the frequency determination unit 321 outputs a frequency determination signal, which is a high level signal, to the AND unit 323.

The voltage determination unit 322 determines whether or not the voltage effective value v input from the voltage detection unit 39 matches the fourth determination condition. As the fourth determination condition, a condition that can be determined that the independent operation has occurred when only the new power supply B2 is connected to the distribution system C is set based on the effective voltage value v. When the voltage determination unit 322 determines that the voltage effective value v matches the fourth determination condition, the voltage determination unit 322 outputs a voltage determination signal, which is a high level signal, to the AND unit 323. The fourth determination condition is not limited.

The AND unit 323 generates a logical product signal of the signal input from the frequency determination unit 321 and the signal input from the voltage determination unit 322, and outputs the signal to the determination unit 35. Therefore, the AND unit 323 is a high-level signal when a frequency determination signal (high level signal) is input from the frequency determination unit 321 and a voltage determination signal (high level signal) is input from the voltage determination unit 322. 1 The determination signal is output to the determination unit 35. That is, when the first determination unit 32 according to the second embodiment determines that the frequency f matches the first determination condition and the voltage effective value v matches the fourth determination condition, the first determination signal. Is output to the determination unit 35.

The second determination unit 33 according to the second embodiment makes a determination based on the frequency f input from the frequency detection unit 31 and the voltage effective value v input from the voltage detection unit 39. The second determination unit 33 includes a frequency determination unit 331, a voltage determination unit 332, and an AND unit 333. The frequency determination unit 331 is a functional block similar to the second determination unit 33 according to the first embodiment, and determines whether or not the frequency f input from the frequency detection unit 31 matches the second determination condition. When the frequency determination unit 331 determines that the frequency f matches the second determination condition, the frequency determination unit 331 outputs a frequency determination signal, which is a high level signal, to the AND unit 333.

The voltage determination unit 332 determines whether or not the voltage effective value v input from the voltage detection unit 39 matches the fifth determination condition. As the fifth determination condition, a condition is set based on the effective voltage value v, in which it can be determined that the independent operation has occurred when only the conventional power supply B1 is connected to the distribution system C. When the voltage determination unit 332 determines that the voltage effective value v matches the fifth determination condition, the voltage determination unit 332 outputs a voltage determination signal, which is a high level signal, to the AND unit 333. The fifth determination condition is not limited.

The AND unit 333 generates a logical product signal of the signal input from the frequency determination unit 331 and the signal input from the voltage determination unit 332 and outputs the signal to the determination unit 35. Therefore, when the frequency determination signal (high level signal) is input from the frequency determination unit 331 and the voltage determination signal (high level signal) is input from the voltage determination unit 332, the AND unit 333 is a high level signal. 2 The determination signal is output to the determination unit 35. That is, when the second determination unit 33 according to the second embodiment determines that the frequency f matches the second determination condition and the voltage effective value v matches the fifth determination condition, the second determination signal. Is output to the determination unit 35.

The third determination unit 34 according to the second embodiment makes a determination based on the frequency f input from the frequency detection unit 31 and the voltage effective value v input from the voltage detection unit 39. The third determination unit 34 includes a frequency determination unit 341, a voltage determination unit 342, and an AND unit 343. The frequency determination unit 341 is a functional block similar to the third determination unit 34 according to the first embodiment, and determines whether or not the frequency f input from the frequency detection unit 31 matches the third determination condition. When the frequency determination unit 341 determines that the frequency f matches the third determination condition, the frequency determination unit 341 outputs a frequency determination signal, which is a high level signal, to the AND unit 343.

The voltage determination unit 342 determines whether or not the voltage effective value v input from the voltage detection unit 39 matches the sixth determination condition. The sixth determination condition is set as a condition that it can be determined that the independent operation has occurred when both the conventional power supply B1 and the new power supply B2 are connected to the distribution system C based on the effective voltage value v. When the voltage determination unit 342 determines that the voltage effective value v matches the sixth determination condition, the voltage determination unit 342 outputs a voltage determination signal, which is a high level signal, to the AND unit 343. The sixth determination condition is not limited.

The AND unit 343 generates a logical product signal of the signal input from the frequency determination unit 341 and the signal input from the voltage determination unit 342 and outputs the signal to the determination unit 35. Therefore, when the frequency determination signal (high level signal) is input from the frequency determination unit 341 and the voltage determination signal (high level signal) is input from the voltage determination unit 342, the AND unit 343 is a high level signal. 3 The determination signal is output to the determination unit 35. That is, when the third determination unit 34 according to the second embodiment determines that the frequency f matches the third determination condition and the voltage effective value v matches the sixth determination condition, the third determination signal. Is output to the determination unit 35.

Also in this embodiment, the same effect as that of the first embodiment can be obtained. Further, according to the present embodiment, the first determination unit 32, the second determination unit 33, and the third determination unit 34 make a determination based on the AND condition of the condition determination for the frequency f and the condition determination for the voltage effective value v. Therefore, the isolated operation detecting device 3a can reliably detect the isolated operation while speeding up the detection by adjusting the set value of each determination condition.

The first determination unit 32 (second determination unit 33, third determination unit 34) replaces the AND unit 323 (333, 343) with the signal and voltage input from the frequency determination unit 321 (331, 341). An OR circuit that generates a logical sum signal with a signal input from the determination unit 322 (332,342) may be provided. That is, in the first determination unit 32 (second determination unit 33, third determination unit 34), the frequency f matches the first determination condition (second determination condition, third determination condition), or the voltage effective value. Even if it is determined that v matches the fourth determination condition (fifth determination condition, sixth determination condition), the first determination signal (second determination signal, third determination signal) is output to the determination unit 35. good.

Further, the detection values used by the first determination unit 32, the second determination unit 33, and the third determination unit 34 for the determination are not limited to the combination of the frequency f and the voltage effective value v. Further, the detection values used may differ between the first determination unit 32, the second determination unit 33, and the third determination unit 34. Further, the first determination unit 32, the second determination unit 33, and the third determination unit 34 may make a determination based on three or more types of detection values. That is, the first determination unit 32, the second determination unit 33, and the third determination unit 34 may each use any number of detection values for determination.

[Third Embodiment]
FIG. 7 is a block diagram showing an internal configuration of the isolated operation detection device according to the third embodiment. In the figure, the same or similar elements as those of the isolated operation detection device 3 (see FIG. 1) according to the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

The independent operation detection device 3b according to the present embodiment is different from the independent operation detection device 3 in that the first determination unit 32, the second determination unit 33, and the determination unit 35 are not provided.

In the first embodiment, the independent operation detection device 3 includes the first determination unit 32, the second determination unit 33, and the third determination unit 34, and the change pattern of the frequency f is any of the first to third determination conditions. The case where the isolated operation is detected when the frequency matches the above is described. However, if it is known in advance that both the new power supply B2 and the conventional power supply B1 are connected to the distribution system C, the determination by the first determination unit 32 and the second determination unit 33 is unnecessary, and the third Only the determination by the determination unit 34 is sufficient. The independent operation detection device 3b according to the present embodiment is used when it is known in advance that both the new power supply B2 and the conventional power supply B1 are connected to the distribution system C, and the determination by the third determination unit 34 It only does.

The independent operation detection device 3b does not include a first determination unit 32, a second determination unit 33, and a determination unit 35. The frequency detection unit 31, the third determination unit 34, and the stop processing unit 38 are the same as the frequency detection unit 31, the third determination unit 34, and the stop processing unit 38 according to the first embodiment. When the third determination unit 34 according to the present embodiment determines that the frequency f matches the third determination condition, the third determination unit 34 outputs the third determination signal as an independent operation detection signal to the stop processing unit 38.

According to the present embodiment, the third determination unit 34 determines the change in the system frequency due to the other independent operation detection device injecting the reactive power into the distribution system C, and determines whether or not the unit is in the independent operation state. .. Since the isolated operation detection device 3b does not inject the reactive power into the distribution system C, it does not induce the voltage flicker phenomenon. That is, in the distribution system C in which the voltage flicker phenomenon does not occur, the voltage flicker phenomenon does not occur even when a large number of power conditioners 1 having the independent operation detection device 3b are added. Further, even when a large number of power conditioners 1 provided with the independent operation detection device 3b are added to the distribution system C in which the voltage flicker phenomenon occurs, the voltage flicker phenomenon is not promoted.

In the present embodiment, the case where the independent operation detection device 3b makes a determination only by the third determination unit 34 has been described, but the present invention is not limited to this. When it is known in advance that the conventional power supply B1 is not connected to the distribution system C and only the new power supply B2 is connected, the independent operation detection device 3b makes a first determination instead of the third determination unit 34. The unit 32 is provided, and only the determination by the first determination unit 32 needs to be performed. Further, when it is known in advance that the new power supply B2 is not connected to the distribution system C and only the conventional power supply B1 is connected, the independent operation detection device 3b replaces the third determination unit 34 with the third determination unit 34. The 2 determination unit 33 is provided, and only the determination by the second determination unit 33 may be performed.

Further, when it is known in advance that the conventional power supply B1 is connected to the distribution system C and it is unclear whether or not the new power supply B2 is connected, the isolated operation detection device 3 according to the first embodiment is the first. 1 The configuration may not include the determination unit 32. In this case, the determination unit 35 determines whether or not it is in the independent operation state based on the determination results of the second determination unit 33 and the third determination unit 34. Further, when it is known in advance that the new power supply B2 is connected to the distribution system C and it is unclear whether or not the conventional power supply B1 is connected, the isolated operation detection device 3 according to the first embodiment is the first. 2 The configuration may not include the determination unit 33. In this case, the determination unit 35 determines whether or not it is in the independent operation state based on the determination results of the first determination unit 32 and the third determination unit 34. Further, when it is known in advance that only either the conventional power supply B1 or the new power supply B2 is connected to the distribution system C, the independent operation detection device 3 according to the first embodiment does not have the third determination unit 34. It may be configured. In this case, the determination unit 35 determines whether or not it is in the independent operation state based on the determination results of the first determination unit 32 and the second determination unit 33.

[Fourth Embodiment]
FIG. 8 is a block diagram for explaining a power conditioner including the analyzer according to the fourth embodiment, and shows the overall configuration of the distribution system C. In the figure, the same or similar elements as those of the power conditioner (see FIG. 1) according to the first embodiment are designated by the same reference numerals, and duplicate description will be omitted.

The analyzer 3c according to the present embodiment is provided in the power conditioner 1 and analyzes the arrangement state of the conventional power supply B1 and the new power supply B2 in the distribution system C when the independent operation occurs. The analyzer 3c includes a frequency detection unit 31, a first determination unit 32, a second determination unit 33, a third determination unit 34, an analysis unit 36, and a display unit 37. The frequency detection unit 31, the first determination unit 32, the second determination unit 33, and the third determination unit 34 are the frequency detection unit 31, the first determination unit 32, and the second of the isolated operation detection device 3 according to the first embodiment. This is the same as the determination unit 33 and the third determination unit 34. Of the analyzer 3c, the combination of the frequency detection unit 31, the first determination unit 32, the second determination unit 33, and the third determination unit 34 corresponds to the "independent operation detection sensor" of the present invention.

The analysis unit 36 is based on the determination result by the first determination unit 32, the determination result by the second determination unit 33, and the determination result by the third determination unit 34, and the conventional power supply B1 and the new power supply in the distribution system C. The arrangement state of B2, that is, the arrangement state of the conventional active type single operation detection device and the new type active type single operation detection device is analyzed. When the first determination signal is input from the first determination unit 32, the analysis unit 36 analyzes that only the new power supply B2 is connected to the distribution system C, and inputs the second determination signal from the second determination unit 33. If so, it is analyzed that only the conventional power supply B1 is connected to the distribution system C. Further, when the third determination signal is input from the third determination unit 34, the analysis unit 36 analyzes that both the conventional power supply B1 and the new power supply B2 are connected to the distribution system C. The analysis unit 36 outputs the analysis result to the display unit 37.

When the third determination signal is input from the third determination unit 34, the analysis unit 36 may further calculate the ratio between the total capacity of the conventional power supply B1 and the total capacity of the new power supply B2. The larger the ratio of the total capacity of the new power supply B2 to the total capacity of the conventional power supply B1, the first change between the time T1-time T2 from the occurrence of a power failure (point a) in the time chart shown in FIG. 2 (c). When the rate Δf changes (point b), the rate of change x1 becomes large, and the rate of change Δf at time T2 (after all new power sources B2 stop injecting reactive power) becomes small. Based on these trends, the analysis unit 36 can calculate the ratio between the total capacity of the conventional power supply B1 and the total capacity of the new power supply B2. The method of calculating the ratio is not limited. Further, the analysis unit 36 does not have to calculate the ratio.

The display unit 37 includes a display, and displays the analysis result input from the analysis unit 36 on the display.

According to the present embodiment, the first determination unit 32, the second determination unit 33, and the third determination unit 34 determine the change in the system frequency due to the other independent operation detection device injecting the reactive power into the distribution system C. do. Then, the analysis unit 36 arranges the conventional power supply B1 and the new power supply B2 in the distribution system C based on the determination results of the first determination unit 32, the second determination unit 33, and the third determination unit 34. To analyze. Since the analyzer 3c does not inject the reactive power into the distribution system C, it does not induce the voltage flicker phenomenon. That is, in the distribution system C in which the voltage flicker phenomenon does not occur, the voltage flicker phenomenon does not occur even when a large number of analyzers 3c are added. Further, even if a large number of analyzers 3c are added to the distribution system C in which the voltage flicker phenomenon occurs, the voltage flicker phenomenon is not promoted.

In the present embodiment, the case where the power conditioner 1 includes the independent operation detection device 3 and the analysis device 3c has been described, but the present invention is not limited to this. The solitary operation detection device 3 may include an analysis unit 36 and a display unit 37 and function as the analysis device 3c. Further, the analyzer 3c may not be provided in the power conditioner 1 and may be independently arranged in the distribution system C together with the voltage sensor 5.

Further, in the present embodiment, the case where the analyzer 3c includes the first determination unit 32, the second determination unit 33, and the third determination unit 34 has been described, but the present invention is not limited to this. As in the case of the third embodiment, when it is known in advance that both the new power supply B2 and the conventional power supply B1 are connected to the distribution system C, the analyzer 3c uses the first determination unit 32 and the second. The determination unit 33 may not be provided, and only the determination by the third determination unit 34 may be performed. In this case, the analysis unit 36 calculates the connection ratio of the total capacity of the new power supply B2 to the total capacity of the entire distribution system C and the connection ratio of the total capacity of the conventional power supply B1 to the total capacity of the entire distribution system C. May be good. The smaller the connection ratio of the new power supply B2 (conventional power supply B1), the smaller the ratio of the amount of injecting reactive power from the new power supply B2 (conventional power supply B1), so that the frequency change rate Δf also becomes smaller. Therefore, the analysis unit 36 can calculate the connection ratio of the new power supply B2 based on the magnitude of the rate of change Δf from time 0 to time T1. Similarly, the analysis unit 36 can calculate the connection ratio of the conventional power supply B1 based on the magnitude of the rate of change Δf from the time T2 to the time T3. The method of calculating the connection ratio is not limited. Further, the analysis unit 36 does not have to calculate these connection ratios. Further, when it is known in advance that the conventional power supply B1 is not connected to the distribution system C and only the new power supply B2 is connected, the analyzer 3c has the second determination unit 33 and the third determination unit 34. However, only the determination by the first determination unit 32 may be performed. In this case, the analysis unit 36 may calculate the connection ratio of the total capacity of the new power supply B2 to the total capacity of the entire distribution system C. The method of calculating the connection ratio is not limited. Further, the analysis unit 36 does not have to calculate the connection ratio. Further, when it is known in advance that the new power supply B2 is not connected to the distribution system C and only the conventional power supply B1 is connected, the analyzer 3c is the first determination unit 32 and the third determination unit 34. However, only the determination by the second determination unit 33 may be performed. In this case, the analysis unit 36 may calculate the connection ratio of the total capacity of the conventional power supply B1 to the total capacity of the entire distribution system C. The method of calculating the connection ratio is not limited. Further, the analysis unit 36 does not have to calculate the connection ratio.

Further, the analyzer 3c does not include the first determination unit 32 in order to confirm only the presence / absence of the connection of the conventional power supply B1 in the distribution system C, and each determination by the second determination unit 33 and the third determination unit 34. May only be done. Further, the analyzer 3c does not include the second determination unit 33 in order to confirm only the presence / absence of the connection of the new power supply B2 in the distribution system C, and only makes each determination in the first determination unit 32 and the third determination unit 34. You may do it. Further, when it is known in advance that only either the conventional power supply B1 or the new power supply B2 is connected to the distribution system C, the analyzer 3c does not include the third determination unit 34, but the first determination unit 32 and the first determination unit 32. Only each determination by the second determination unit 33 may be performed. In this case, the analysis unit 36 calculates the connection ratio of the total capacity of the conventional power supply B1 to the total capacity of the entire distribution system C, or the connection ratio of the total capacity of the new power supply B2 to the total capacity of the entire distribution system C. May be good. The method of calculating the connection ratio is not limited. Further, the analysis unit 36 does not have to calculate the connection ratio.

The solitary operation detection sensor, the solitary operation detection device, the analyzer, and the solitary operation detection method according to the present invention are not limited to the above-described embodiments. The specific configuration of each part of the solitary operation detection sensor, the solitary operation detection device, the analyzer, and the solitary operation detection method according to the present invention can be variously redesigned.

1: Power conditioner, 3,3a: Independent operation detection device, 3c: Analyzer, 31: Frequency detection unit, 32: First determination unit, 33: Second determination unit, 34: Third determination unit, 35: Judgment Unit, 36: Analysis unit, 39: Voltage detection unit

Claims (13)

A detector that detects the electrical characteristics of the output of the power conditioner,
A first determination unit that determines whether or not the detection value detected by the detection unit matches the first determination condition,
A second determination unit that determines whether or not the detected value matches the second determination condition,
A third determination unit that determines whether or not the detected value matches the third determination condition,
Equipped with
The first determination condition is the electrical one generated by the fact that only the new active type isolated operation detection device arranged in the distribution system to which the power conditioner is connected injects the reactive power into the distribution system. It is a condition for judging the change of characteristics.
The second determination condition is to determine the change in the electrical characteristics caused by the injection of the active signal into the distribution system only by the conventional active type isolated operation detection device arranged in the distribution system. It is a condition of
The third determination condition is caused by the fact that the new type active type isolated operation detection device and the conventional active type independent operation detection device arranged in the distribution system inject an active signal into the distribution system. It is a condition for determining the change in the electrical characteristics.
A single operation detection sensor characterized by this. The first determination condition is that the rate of change of the detected value changes from the first time to the second time after the detection value starts to change, and then the rate of change changes from the third time to the fourth time. Did not change,
In the second determination condition, the rate of change does not change from the 5th time to the 6th hour after the detection value starts to change, and then the rate of change does not change from the 7th time to the 8th time. That's what I did
The third determination condition is that the rate of change changes from the 9th hour to the 10th hour after the detection value starts to change, and further changes from the 11th hour to the 12th hour. ,
The isolated operation detection sensor according to claim 1. The detection unit detects the frequency of the output voltage of the power conditioner as the detection value.
The isolated operation detection sensor according to claim 1 or 2. The detection unit further detects a second detection value different from the detection value.
The first determination unit determines whether or not the detection value matches the first determination condition and the second detection value matches the fourth determination condition.
The second determination unit determines whether or not the detection value matches the second determination condition and the second detection value matches the fifth determination condition.
The third determination unit determines whether or not the detection value matches the third determination condition and the second detection value matches the sixth determination condition.
The isolated operation detection sensor according to any one of claims 1 to 3. The isolated operation detection sensor according to any one of claims 1 to 4,
If it is determined that the first determination unit matches, the second determination unit determines that they match, or the third determination unit determines that they match, the determination unit determines that the unit is in an independent operation state. When,
A stand-alone operation detection device characterized by being provided with. The isolated operation detection sensor according to any one of claims 1 to 4,
Based on the determination result by the first determination unit, the determination result by the second determination unit, and the determination result by the third determination unit, the conventional active type independent operation detection device in the distribution system and An analysis unit that analyzes the arrangement state of the new active type isolated operation detection device, and
An analyzer characterized by being equipped with. A detector that detects the electrical characteristics of the output of the power conditioner,
A determination unit that determines whether or not the detection value detected by the detection unit matches the determination condition,
Equipped with
The determination condition is that the electrical characteristics generated by the fact that only the new active type isolated operation detection device arranged in the distribution system to which the power conditioner is connected injects the reactive power into the distribution system. It is a condition for judging the change,
A single operation detection sensor characterized by this. A detector that detects the electrical characteristics of the output of the power conditioner,
A determination unit that determines whether or not the detection value detected by the detection unit matches the determination condition,
Equipped with
The determination condition is the electrical characteristic generated by the fact that only the conventional active type isolated operation detection device arranged in the distribution system to which the power conditioner is connected injects the reactive power into the distribution system. It is a condition for judging the change of
A single operation detection sensor characterized by this. A detector that detects the electrical characteristics of the output of the power conditioner,
A determination unit that determines whether or not the detection value detected by the detection unit matches the determination condition,
Equipped with
The determination condition is that the new active type independent operation detection device and the conventional active type single operation detection device arranged in the distribution system to which the power conditioner is connected inject reactive power into the distribution system. It is a condition for determining the change in the electrical characteristics caused by the above.
A single operation detection sensor characterized by this. A detection process that detects the electrical characteristics of the output of the power conditioner,
The first determination step of determining whether or not the detection value detected in the detection step matches the first determination condition, and
The second determination step of determining whether or not the detected value matches the second determination condition, and
A third determination step of determining whether or not the detected value matches the third determination condition, and
If it is determined that they match in the first determination step, if they are determined to match in the second determination step, or if they are determined to match in the third determination step, it is determined that they are in an independent operation state. Process and
Equipped with
The first determination condition is the electrical one generated by the fact that only the new active type isolated operation detection device arranged in the distribution system to which the power conditioner is connected injects the reactive power into the distribution system. It is a condition for judging the change of characteristics.
The second determination condition is to determine the change in the electrical characteristics caused by the injection of the active signal into the distribution system only by the conventional active type isolated operation detection device arranged in the distribution system. It is a condition of
The third determination condition is caused by the fact that the new type active type isolated operation detection device and the conventional active type independent operation detection device arranged in the distribution system inject an active signal into the distribution system. It is a condition for determining the change in the electrical characteristics.
A method for detecting isolated operation. A detection process that detects the electrical characteristics of the output of the power conditioner,
A determination step of determining whether or not the detection value detected in the detection step matches the determination condition, and
When it is determined that they match in the determination step, the determination step of determining that the unit is in an independent operation state and
Equipped with
The determination condition is that the electrical characteristics generated by the fact that only the new active type isolated operation detection device arranged in the distribution system to which the power conditioner is connected injects the reactive power into the distribution system. It is a condition for judging the change,
A method for detecting isolated operation. A detection process that detects the electrical characteristics of the output of the power conditioner,
A determination step of determining whether or not the detection value detected in the detection step matches the determination condition, and a determination step.
When it is determined that they match in the determination step, the determination step of determining that the unit is in an independent operation state and
Equipped with
The determination condition is the electrical characteristic generated by injecting an active signal into the distribution system only by a conventional active type isolated operation detection device arranged in the distribution system to which the power conditioner is connected. It is a condition for judging the change of
A method for detecting isolated operation. A detection process that detects the electrical characteristics of the output of the power conditioner,
A determination step of determining whether or not the detection value detected in the detection step matches the determination condition, and a determination step.
When it is determined that they match in the determination step, the determination step of determining that the unit is in an independent operation state and
Equipped with
The determination condition is that the new active type independent operation detection device and the conventional active type single operation detection device arranged in the distribution system to which the power conditioner is connected inject an active signal into the distribution system. It is a condition for determining the change in the electrical characteristics caused by the above.
A method for detecting isolated operation.

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