JP2014130057A - Current sensor detection method and power control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a current sensor detection method and a power control system for having a system normally operate according to a desired control method.SOLUTION: A current sensor detection method is provided with: a step A where a direction of current flowing in a power line is detected as a first current direction by a current sensor; and a step B where it is determined if the direction of current detected by the current sensor has changed to a second current direction flowing in the reverse direction to the first current direction within a prescribed time after the first current direction is detected at the step A. There is also provided with a step C where when the current changes to the second current direction at the step B, it is detected that the current sensor is fitted to a first power line and, when the direction does not change to the second current direction at the step B, it is detected that the current sensor is fitted to a second power line.

Description

  The present invention relates to a current sensor detection method and a power control system for detecting a position of a current sensor attached to a power control system.

  In recent years, a power control system combining a solar cell device and a power storage device has been popularized. In such a power control system, surplus power that is supplied by supplying power to the load among the generated power of the solar battery device can be stored in the power storage device, or can be sold by flowing backward to the power system.

  There are the following two control methods for controlling the power control system. The first control method is a method in which a “push-up effect” is obtained by preferentially reversely flowing the generated power of the solar cell device and supplying the power consumption of the load from the power storage device (hereinafter referred to as control with push-up). ). In the second control method, there is no “push-up effect” in which the power generation power of the solar cell device is insufficient from the power consumption of the load from the power storage device (hereinafter referred to as “no push-up control”). )

  In the power control system, a plurality of current sensors are provided as necessary. For example, the power control system shown in FIG. 1 includes a current sensor C that measures a discharge / charge current and a current sensor D that measures an output current of the solar cell device. Further, in the power control system, when the control with the push-up is performed, a current sensor A for measuring the power consumption of the load is provided. Further, in the power control system, when the control without push-up is performed, a current sensor B that measures a current in the power selling direction to the power system side is provided instead of the current sensor A.

  Moreover, since the current sensor has a polarity, it may be applied in a state where the polarity is reversed. Thus, a method has been proposed in which current information is corrected correctly at the time of calculation when the polarity of the current sensor is incorrect (see, for example, Patent Document 1 and Patent Document 2).

JP 2004-297959 A JP-A-11-225441

In the power control system, whether to perform the operation with the push-up control or the control without the push-up must be determined in advance on the system. Therefore, it is necessary to arrange the current sensor according to the above control method, but since many wirings are gathered in the distribution board,
There may be a construction error that causes the current sensor to be misplaced. When such a construction error occurs, the power control system cannot operate normally based on a predetermined control method. However, Patent Documents 1 and 2 cannot detect an error in the arrangement of the current sensors.

  An object of the present invention is to provide a current sensor detection method and a power control system for detecting the position of a current sensor and causing the system to operate normally according to a desired control method. .

  A current sensor detection method according to an embodiment of the present invention is attached to a first power line that connects a power system and a distribution board or a second power line that connects the distribution board and a load. A current sensor for detecting the direction of current flowing through the line; a solar cell device connected to the distribution board via a third power line; and a fourth power line connected to the distribution board. A power storage system, and a power control system that alternately performs power selling to transmit power generated by the solar cell device to the power system and power purchase to transmit power consumption from the power system to the load. It is a method of detecting which of the first power line and the second power line is attached. In this embodiment, the current sensor detects the direction of the current flowing through the line as a first current direction, and the current sensor detects the first current direction in the step A within a predetermined time. And step B for determining whether the direction of the current detected by the sensor has changed to the second current direction flowing in the opposite direction to the first current direction. In the present embodiment, when the current direction is changed in the second current direction in the step B, it is detected that the current sensor is attached to the first power line, and the second current direction is detected in the step B. If not, step C is provided for detecting that the current sensor is attached to the second power line.

  A power control system according to an embodiment of the present invention is attached to a first power line connecting between a power system and a distribution board or a second power line connecting between the distribution board and a load. A current sensor for detecting a direction of a current flowing through the line, a solar cell device connected to the distribution board via a third power line, and an electricity storage connected to the distribution board via a fourth power line And a controller that indicates whether the current sensor is attached to the first power line or the second power line. In addition, the present embodiment is a power control system that alternately performs power sale for transmitting the generated power of the solar cell device to the power system and power purchase for transmitting power consumption from the power system to the load. Further, in the present embodiment, the control device detects the first current direction by the first detection means detecting the current sensor with the direction of the current flowing through the line as the first current direction, and the first detection means. Determining means for determining whether the direction of the current detected by the current sensor has changed to a second current direction flowing in a direction opposite to the first current direction within a predetermined time from when the current is detected. Moreover, in this embodiment, based on the information of the said determination means, when it changes to the said 2nd current direction, it detects that the said current sensor is attached to the said 1st electric power line, and the said 2nd current direction When it does not change, it has a 2nd detection means to detect that the said current sensor is attached to the said 2nd electric power line.

  According to the current sensor detection method and the power control system according to the embodiment of the present invention, it is possible to detect whether the current sensor is provided in the first power line or the second power line. Thereby, it can be confirmed whether the current sensor is attached to the desired power line. As a result, according to the present embodiment, the power control system can be operated normally.

It is a block diagram which shows one structure of an electric power control system. It is a wiring diagram explaining the position where the current sensor with which an electric power control system is equipped is arrange | positioned. It is a control flowchart for demonstrating the current sensor detection method which concerns on one Embodiment of this invention. It is a control flowchart for demonstrating the current sensor detection method which concerns on other embodiment of this invention.

A current sensor detection method and a power control system according to the present invention will be described with reference to the drawings. In addition, the description which overlaps with background art is abbreviate | omitted.

<Configuration of power control system>
As shown in FIG. 1, the power control system X includes a power storage device 1, a solar cell device 2, and a control device 3. Moreover, in the following description, as shown in FIG. 1, the power transmission line connecting between the distribution board 4 and the commercial power system (hereinafter, power system 5) is the first power line L1, the distribution board 4 and The power transmission line connecting the load 6 is the second power line L2, the power transmission line connecting the distribution board 4 and the solar cell device 2 is the third power line L3, the distribution board 4 and the power storage device 1 A power transmission line connecting the two is referred to as a fourth power line L4. The power control system X is provided with a plurality of current sensors. As shown in FIG. 1, in this embodiment, the current sensor A is a device that measures the direction of the current flowing through the second power line L2. In the present embodiment, the current sensor B is a device that measures the direction of the current flowing through the first power line L1. In the present embodiment, the current sensor C is a device that measures the direction of the current flowing through the fourth power line L4. A sensor that measures the direction of the current flowing through the third power line L3 is referred to as a current sensor D.

  The power storage device 1 is for a storage battery 10 that stores DC power, and for a power storage device that converts AC power into DC power so that the storage battery 10 can be charged, or converts the DC output of the storage battery 10 into AC output. Power conditioner 11. In the present embodiment, a control device 3 that controls charging, discharging, or security of the device is disposed inside the power storage device 1. The electric power for charging or discharging the power storage device 1 is measured by the current sensor C. And in the control apparatus 3, it calculates based on the information of the electric current measured with the current sensor C, and obtains information, such as the output electric power from the storage battery 10, or the electric power used for charge.

  Since the power storage device 1 can be charged with nighttime electric power, daytime power purchase can be reduced by supplying the charged electric power to the load 6 in the daytime. As a result, if the power storage device 1 is provided, it is possible to reduce power purchase during daytime peak power, thus reducing the burden on the power company and reducing the contract power and keeping the electricity bill low. Become. Moreover, since the electrical storage apparatus 1 can supply electric power to the load 6 at night etc. when there is no power generation of the solar cell apparatus 2, it can be used as an emergency power source even during a power failure due to a disaster or the like.

  The solar cell device 2 includes a solar cell 20 in which a plurality of solar cell modules are electrically connected in series, and a power conditioner 21 that converts the generated power of the solar cell 20 into AC power. The AC power output from the power conditioner 21 can be transmitted to the power system 5 or the load 6 via the distribution board 4 and the power line, respectively.

  In addition to the control of power storage device 1 described above, for example, when current sensor is attached to first power line L1 or second power line L2, control device 3 determines in which line the current sensor is located. It has a function to detect. Therefore, the control device 3 detects the direction of the current flowing through the power line as a first current direction that is a unidirectional current by a current sensor, and detects the first current direction by the first detection unit. Determining means for determining whether the direction of the current detected by the current sensor has changed to the second current direction flowing in the direction opposite to the first current direction within a predetermined time from the time when the current is detected. Furthermore, the control device 3 detects that the current sensor is attached to the first power line L1 when the direction is changed to the second current direction based on the information of the determination unit, and has not changed to the second current direction. In this case, there is a second detection means for detecting that the current sensor is attached to the second power line L2. The control mechanism of the control device 3 is performed by a calculation unit such as a CPU provided therein. The calculation unit may have a function of controlling the power conditioner 11.

The distribution board 4 has a plurality of breakers and terminal blocks. In addition, the distribution board 4 is configured to open and close an electric circuit with a breaker installed between the power storage device 1, the solar cell device 2, the power system 5, and the load 6. Thereby, the distribution board 4 can supply electric power generated by the solar cell device 2 to the power storage device 1, the power system 5, and the load 6 through each power line.

  Thus, the power control system X is a system that alternately performs power selling for transmitting the generated power of the solar battery device 2 to the power system 5 and power purchase for transmitting power consumption from the power system 5 to the load 6.

  The power control system X may be provided with the display device 7. The display device 7 can display information such as the amount of power sold by the solar cell device 2 and the amount of power consumed by the load 6 (amount of power purchased). Such information is calculated based on the current information of the current sensor E arranged between the distribution board 4 and the power system 5. The display device 7 can also display the position information of the current sensor detected by the second detection means of the control device 7.

  Next, a current sensor detection method in the power control system X will be described.

(Embodiment 1)
FIG. 2 is a wiring diagram schematically showing the arrangement of each current sensor in the case of control with push-up and the case of control without push-up of the power control system X.

  The output of the power storage device 1 is a single-phase three-wire system, and current sensors are arranged at two locations of the U phase and the W phase among the three phases of the U phase, the V phase, and the W phase. Here, in the case of the control with push-up, the current sensor is located at positions A1 and A2 between the distribution board 4 and the load 6. On the other hand, in the case of the control without push-up, the current sensor is at the positions B1 and B2. As shown by the arrows in FIG. 2, it can be confirmed that the current flows only in one direction (the power purchase direction) in the current sensors A1 and A2. On the other hand, in the current sensors B1 and B2, it can be confirmed that the current flows in both directions (the power purchase direction and the power sale direction). Therefore, in the present embodiment, the position of the current sensor is detected by utilizing the fact that the current flows are different at positions A1 and A2 and B1 and B2.

  FIG. 3 is a control flowchart for detecting which side of the current sensor A1 or B1 (A2 or B2) in FIG. 2 is arranged. In the following description, for the sake of convenience, the U phase side where the current sensor A1 or B1 is placed is referred to as the current sensor 1, and the W phase side where the current sensor A2 or B2 is placed is referred to as the current sensor 2 for the sake of convenience. I will decide. Moreover, in this embodiment, since the phase of the current sensor 1 (current sensor A1 or B1) and the current sensor 2 (current sensor A2 or B2) are reversed, the current is adjusted according to whether the area is 50 Hz or 60 Hz. The measurement times of the sensor 1 and the current sensor 2 are shifted.

  First, the current direction of the current sensor 1 is measured in STEP1. Next, the current direction of the current sensor 2 is measured in STEP2. Next, in STEP 3, when the current directions of the current sensor 1 and the current sensor 2 are the same, this current direction is defined as the first current direction. In STEP 1 to 3, this is a step (step A) in which the current sensor detects the direction of the current flowing through the first power line L1 or the second power line L2 as the first current direction.

Next, after the current in the first current direction is detected in STEP 3, the current direction of the current sensor 1 is measured in STEP 4, and the current direction of the current sensor 2 is measured in STEP 5. Next, in STEP 6, it is determined whether the direction of the current detected in STEP 4 and STEP 5 has changed from the first current direction to the second current direction that flows in the opposite direction to the first current direction. STEP 4 to STEP 6 are performed within a predetermined time from when the current in the first current direction is detected in STEP 3. That is, STEP 4 to STEP 6 determine whether the direction of the current detected by the current sensor has changed from the first current direction to the second current direction within a predetermined time from when the first current direction is detected in Step A (STEP 3). Step (Step B). At this time, the predetermined time may be a time when it can be confirmed that the power generated by the solar cell device 2 is sold. Therefore, the predetermined time may be, for example, about 10 to 24 hours when the weather is fine.

  In STEP 6, when the direction of the current flowing through the current sensor changes from the first current direction to the second current direction, in STEP 7, it is detected that the current sensors 1 and 2 are arranged in B1 and B2. As described above, this determination is made on the basis of the fact that the current flows in both directions (the power purchase direction and the power sale direction) in the current sensors located at B1 and B2.

  On the other hand, if the direction of the current measured by the current sensor does not change from the first current direction even after the predetermined time has elapsed, it is detected that the current sensors 1 and 2 are arranged at A1 and A2. (STEP8 and STEP9).

  As described above, in STEP 7 to 9, when the second current direction is changed in Step B (STEP 6), it is detected that the current sensors 1 and 2 are attached to the first power line L 1. This is a step (step C) for detecting that the current sensors 1 and 2 are attached to the second power line L2 when the direction does not change in two current directions.

  Next, in STEP 10, the results of STEP 7 and STEP 9 are output as determination information (position information). Here, in STEP 10, if the result obtained through STEP 7 is detected as position information, if the power control system X is a system that operates with push-up control, the current sensor is misplaced. Become. On the other hand, in STEP 10, if the result obtained through STEP 9 is detected as position information, if the power control system X is a system that operates without push-up control, the current sensor is misplaced. Become. In addition, if the position information of the current sensor is output to a separately provided display unit (not shown) or the like, the installer can easily confirm it. In addition, when an error occurs in the arrangement of the current sensor, warning information may be transmitted so that the abnormal operation is stopped by preventing output from the power storage device 1.

  Thus, in the present embodiment, it is possible to detect whether or not the current arrangement of current sensors is correct in a system that performs desired control. Thereby, even if a builder performs construction of the current sensor by mistake, it is possible to perform an operation to correct the placement of the current sensor.

(Embodiment 2)
The present embodiment is different from the first embodiment in that the position of the current sensor can be detected even when the current direction of the current sensor 1 and the current direction of the current sensor 2 are opposite directions. FIG. 4 is a control flow diagram according to Embodiment 2 of the present invention.

  First, the current direction of the current sensor 1 is measured in STEP1. Next, the current direction of the current sensor 2 is measured in STEP2. Next, in STEP 11, it is determined whether or not the current direction of the current sensor 1 is the same as the current direction of the current sensor 2. Here, if the current direction of the current sensor 1 and the current direction of the current sensor 2 are the same, the subsequent steps can be detected by proceeding in the same procedure as in STEP 3 and subsequent steps of the embodiment.

On the other hand, if the current direction of the current sensor 1 is different from the current direction of the current sensor 2 in STEP 11, the polarity of the current sensor 1 or the current sensor 2 is reversed so that the current direction is recognized as the same in STEP 12. Control). Control for inverting the polarity of the current sensor 1 or the current sensor 2 in STEP 12 can be performed by the control device 3. In the control in STEP 12, for example, by reversing the polarity of the current sensor 2, it is possible to recognize that the direction of the current measured by the current sensor 2 is the same as the direction of the current measured by the current sensor 1. . At this time, the direction of the actual current measured by the current sensor 2 does not change. As a result, it can be recognized that the current direction of the current sensor 1 is the same as the current direction of the current sensor 2, so that the current direction of the current sensor 1 and the current sensor 2 is defined as the first current direction in the next STEP3. Will be able to. As a result, in this embodiment, even when the current direction of the current sensor 1 and the current direction of the current sensor 2 are different, the position of the current sensor can be detected.

  Moreover, in the control apparatus 3, if the output of a positive direction is detected from a current sensor, it can also be determined that the current sensor is flowing in the power purchase direction. On the other hand, if the control device 3 detects an output in the negative direction from the current sensor, it can also be determined that the current sensor is flowing in the power selling direction. Therefore, in the flowchart shown in FIG. 4, the polarity of the current sensor 2 is reversed and corrected so as to match the current sensor 1. For example, a current sensor (current sensor 1) in which the current direction indicates the power purchase direction. Or you may correct | amend so that it may match | combine with the current sensor 2). As a result, even if the current direction of the current sensor 1 is negative, the input signal from the current sensor input to the control device 3 can be positive, so that power is sold within one day. Considering that the time is short, it is possible to reduce the probability of misidentifying the power purchase direction as the power sale direction. In addition, until the reversal of the current direction is confirmed in STEPs 4 to 6, the display device 7 is erroneously displayed or controlled by the power conditioner 11 or the like using the current sensors 1 and 2. Can be reduced.

X: Power control system 1: Power storage device 2: Solar cell device 3: Control device 4: Distribution board 5: Power system 6: Load 7: Display device 10: Storage battery 20: Solar cell 11, 21: Power conditioner A to E: Current sensors L1 to L4: First to fourth power lines

Claims (2)

A current sensor for detecting a direction of a current flowing through the line, attached to a first power line connecting between the power system and the distribution board or a second power line connecting between the distribution board and the load; ,
A solar cell device connected to the distribution board via a third power line;
A power storage device connected to the distribution board via a fourth power line;
In the power control system that alternately performs power selling to transmit the generated power of the solar cell device to the power system and power purchase to transmit power consumption from the power system to the load,
A current sensor detection method for detecting whether the current sensor is attached to the first power line or the second power line,
Detecting the direction of the current flowing through the line as a first current direction by the current sensor;
It is determined whether or not the direction of the current detected by the current sensor has changed to a second current direction that flows in a direction opposite to the first current direction within a predetermined time from when the first current direction is detected in Step A. Step B
When the step B changes to the second current direction, it is detected that the current sensor is attached to the first power line, and when the step B does not change to the second current direction, And a step C of detecting that a current sensor is attached to the second power line. A current sensor for detecting a direction of a current flowing through the line, attached to a first power line connecting between the power system and the distribution board or a second power line connecting between the distribution board and the load; ,
A solar cell device connected to the distribution board via a third power line;
A power storage device connected to the distribution board via a fourth power line;
A controller that indicates whether the current sensor is attached to the first power line or the second power line;
A power control system that alternately performs power selling to transmit power generated by the solar cell device to the power system and power purchase to transmit power consumption from the power system to the load,
The control device includes a first detection unit configured to detect the direction of the current flowing through the line as a first current direction by the current sensor, and within a predetermined time from when the first detection unit detects the first current direction. Determining means for determining whether the direction of the current detected by the current sensor has changed to a second current direction flowing in a direction opposite to the first current direction; and based on information of the determining means, the second current direction When the current sensor is changed to, it is detected that the current sensor is attached to the first power line, and when the current sensor is not changed in the second current direction, it is detected that the current sensor is attached to the second power line. A power control system having second detection means for

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