JP2015050835A - Distributed power supply system, power conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress life difference by eliminating deviation of output from a plurality of non-natural energy type distributed power supply systems.SOLUTION: A distributed power supply system includes a power conditioner 10 for controlling the output from a power supply device 11, a current sensor 12 connected with the power conditioner 10, other power conditioner 20 for controlling the output from other power supply device 21, and other current sensor 22 connected with other power conditioner 20. When the current sensor 12 and other current sensor 22 are installed at a position where the current from a system is detected as the same forward power flow, the power conditioner 10 increases or decreases the forward power flow threshold thereof for inverse power prevention, with reference to other forward power flow threshold of other power conditioner 20 for inverse power prevention, as the reference threshold.

Description

  The present invention relates to a distributed power supply system and a power conditioner.

  A distributed power supply system in which a natural energy type power supply system such as a solar battery and a non-natural energy type power supply system such as a storage battery or a fuel cell are connected to the same commercial power supply system (hereinafter abbreviated as a system as appropriate) Exists (see, for example, Patent Document 1). It is also conceivable that a plurality of non-natural energy type power supply systems are interconnected in the same system to form a distributed power supply system. Each power supply system can perform a linked operation in which AC power is output in conjunction with the grid and a self-sustained operation in which AC power is output independently from the grid, such as during a system power failure.

  In the case of a non-renewable energy type power supply system, unlike a natural energy type power supply system such as solar power generation, an electric power company must be separately certified to sell power to the system. In the current Japanese system, it is stipulated that the electric power obtained from the non-natural energy type power supply system is controlled so as not to sell power. For this reason, in order to prevent reverse power flow (current in the power selling direction) to the system, each power conditioner of the non-natural energy type power supply system is connected with a current sensor for detecting current between the system and the system. . Each power conditioner performs control so that a predetermined forward flow (current in the power purchase direction) always flows through the current sensor in order to prevent power sale to the system. Each power conditioner reduces its output so that the forward power from the grid increases when the forward power flow is lower than a predetermined threshold (forward power flow threshold) during power supply to the load. In addition, each power conditioner increases its output so as to reduce the forward flow from the grid when the forward flow is higher than the forward flow threshold.

JP 11-46458 A

  When power conditioners of multiple non-renewable energy type power systems are connected to the same system, each current sensor must be connected so that the output of one power conditioner is not detected as a reverse power flow in the current sensor of another power conditioner. It is necessary to install. For this reason, each current sensor is installed in the system | strain side rather than the branch point where each power conditioner connects, and detects the current from a system | strain as the same electric current (forward power flow).

  Here, different values may be set for the forward flow threshold values of the plurality of inverters depending on, for example, the type of product or manufacturer, and the threshold values may not be identified. When the forward power flow thresholds are different, there is a problem that only a specific power conditioner performs output, and other power conditioners do not perform output. As described above, after each current sensor detects the same forward flow, a power conditioner with a forward flow threshold higher than the forward flow reduces the output, and a power conditioner with a forward flow threshold lower than the forward flow increases the output. . For this reason, as a result, the output is concentrated on the power conditioner having a low forward flow threshold, and the output of the power conditioner having a high forward flow threshold is stopped. If such a situation continues, there may be a negative effect such that the SOH (State of Health) of the power supply apparatus where the output is concentrated is lower than the other and a life difference occurs between the distributed power supply systems.

  Accordingly, an object of the present invention made in view of such a point is to provide a distributed power supply system and a power conditioner that can eliminate the bias of outputs of a plurality of non-renewable energy type power supply systems and suppress the difference in life between the power supply systems. There is.

In order to solve the above-described problems, a distributed power supply system according to an embodiment of the present invention includes:
A power conditioner that controls the output of the power supply;
A current sensor connected to the inverter;
With other inverters that control the output of other power supplies,
Another current sensor connected to the other power conditioner,
When the current sensor and the other current sensor are installed at a position where the current from the system is detected as the same forward flow,
The power conditioner uses another forward power flow threshold for preventing reverse power flow of the other power conditioner as a reference threshold,
The forward power flow threshold value for preventing reverse power flow of the power conditioner is increased or decreased with respect to the reference threshold value.

The power conditioner according to one embodiment of the present invention is
A power conditioner that is connected to a current sensor and controls the output of the power supply device, and is connected to the same system as other power conditioners,
When the current sensor and the current sensor of the other power conditioner are installed at a position where the current from the system is detected as the same forward flow,
The other forward power flow threshold for preventing reverse power flow of the other power conditioner is set as a reference threshold,
The power conditioner includes a control unit that increases or decreases a forward power flow threshold value for preventing a reverse power flow from the reference threshold value.

  According to the distributed power supply system and the power conditioner according to the embodiment of the present invention, it is possible to eliminate the uneven output of the plurality of non-natural energy type power supply systems and reduce the life difference between the power supply systems.

It is a figure which shows the structure of the distributed power supply system which concerns on one Embodiment of this invention. It is an output control flowchart of the conventional power conditioner. It is a figure which shows the change of the output by the conventional output control. It is a 1st forward power flow threshold value control flowchart of this invention. It is a figure which shows the change of the output by 1st forward power flow threshold value control. It is a 2nd forward power flow threshold value control flowchart of this invention. It is a figure which shows the change of the output by 2nd forward power flow threshold value control. It is an output control flowchart concerning a 1st embodiment. It is a figure which shows the change of the output by the output control which concerns on 1st Embodiment. It is an output control flowchart concerning a 2nd embodiment. It is a figure which shows the change of the output by the output control which concerns on 2nd Embodiment.

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

  As shown in FIG. 1, a distributed power system according to an embodiment of the present invention includes a first power system having a first power conditioner 10, a first power device 11, and a first current sensor 12, and a second power condition. And a second power supply system having a second power supply device 21 and a second current sensor 22, a general load 30, a specific load 40, and a changeover switch 50 for switching a power supply source to the specific load 40. In FIG. 1, a solid line connecting the functional blocks represents a wiring through which power flows. Moreover, in FIG. 1, the broken line which connects each power conditioner and a current sensor represents the flow of the control signal or the information communicated. The communication indicated by the broken line may be wired communication or wireless communication. Various systems including a physical layer and a logical layer can be employed for communication of control signals and information. For example, communication by a short-range communication method such as ZigBee (registered trademark) can be employed. In addition, various transmission media such as infrared communication and power line communication (PLC) can be used. In addition, various protocols such as ZigBee SEP2.0 (Smart Energy Profile 2.0), ECHONET Lite (registered trademark), etc. are operated on the physical layer suitable for each communication. May be.

  In the present embodiment, it is assumed that the first power supply device 11 of the first power supply system and the second power supply device 21 of the second power supply system are storage batteries. The 1st power supply device 11 and the 2nd power supply device 21 (storage battery) can store the electric power supplied from the system, the electric power which the solar cell which is not illustrated, etc. generated. As shown in the figure, the first current sensor 12 and the second current sensor 22 are installed at a position where the current from the system is detected as the same forward flow. The value detected by the first current sensor 12 is communicated to the first power conditioner 10. Further, the value detected by the second current sensor 22 is communicated to the second power conditioner 20. In addition, the first forward flow threshold for the first power conditioner 10 to prevent reverse flow and the second forward flow threshold for the second power conditioner 20 to prevent reverse flow are different values. It is assumed that the power conditioner does not have information on the forward flow threshold of the other power conditioner. The general load 30 is a load that is normally used in homes and offices, and is an electric device such as a television, an air conditioner, a dryer, or a vacuum cleaner. The specific load 40 is a load used during a self-sustaining operation such as a system power failure, and is an electrical device such as an emergency lighting. The changeover switch 50 is a switch for switching the power supply source to the specific load 40 by a user operation. When the changeover switch 50 is set on the first power conditioner 10 side as shown in the figure, the power is automatically supplied from the first power conditioner 10 to the specific load 40 without the user's operation during the independent operation. There is an advantage that is done.

  In the present embodiment, the first power conditioner 10 adjusts its own first forward flow threshold value, thereby performing control to eliminate the output bias between the power conditioners. First, a conventional output control method in which the forward flow threshold is not adjusted will be described before the output control method according to the embodiment of the present invention. Hereinafter, for the sake of simplicity, the forward current and the forward current threshold are expressed in watts (W), but current / power measurement and conversion can be appropriately performed by those skilled in the art. The first forward flow threshold of the first power conditioner 10 is 22 W, the second forward flow threshold of the second power conditioner 20 is 30 W, the power consumption of the general load 30 is 100 W, and the specific load 40 from the first power conditioner 10 is set. The effect of the output on is not considered. The first power conditioner 10 and the second power conditioner 20 can adjust the output in the range from zero to the maximum output (for example, 2.5 kW) of each power supply device. In each chart, the output of the first power conditioner 10 is “first output”, the output of the second power conditioner 20 is “second output”, the first forward flow threshold is “first threshold”, the first Two forward flow thresholds are abbreviated as “second threshold”, and power from the grid is abbreviated as “forward flow”. Further, the processing steps of each flowchart are performed by a control unit configured by a suitable processor provided in each power conditioner.

  FIG. 2 is an output control flow of the conventional power conditioner, and FIG. 3 is a diagram showing a change in output by the conventional output control. In the initial state T1, 30 W of power (forward power flow) from the system is supplied to the general load 100 W, and 70 W of the output of the second power conditioner 20 is supplied. At this time, the first power conditioner 10 measures the forward flow by the first current sensor 12 (step S101), the forward flow 30W is higher than the first forward flow threshold 22W (Yes in step S102), and the first power supply device 11 (Yes in step S103), the output is increased by the difference of 8W so that the forward flow 30W becomes the same value as the first forward flow threshold 22W (step S104). On the other hand, when the state T2 is reached, the second power conditioner 20 measures the forward flow by the second current sensor 22 (step S101), and the forward flow 22W is lower than the second forward flow threshold 30W (Yes in step S102). Since there is room for adjusting the output of the second power supply device 21 (Yes in step S103), the output is reduced by the difference of 8W so that the forward flow 22W becomes the same value as the second forward flow threshold 30W (step S104). . Thus, as a result of the first power conditioner 10 increasing the output in accordance with the forward flow and the second power conditioner 20 decreasing the output (T3 to T19), in the final state T20, the first power conditioner 10 The output (78 W) is concentrated, and output bias occurs. In this final state T20, the output of the second power conditioner 20 is zero, and it is impossible to reduce the output to a value smaller than zero, so the output cannot be adjusted (output adjustment is impossible). .

  Here, as shown in FIGS. 2 and 3, when the forward power flow threshold is different among the plurality of distributed power supply systems, the output is concentrated on the distributed power supply system having the lower forward power flow threshold. In other words, the first power conditioner 10 uses the second forward flow threshold value of the second power conditioner 20 as a reference threshold value, and increases or decreases the first forward flow threshold value with respect to the reference threshold value. In addition, the output can be distributed among the second power supply systems. Here, there is no problem when the second forward flow threshold of the second power supply system is known, but normally, the information of the forward flow threshold of the other power conditioner is not input to each power conditioner. Hereinafter, a method in which the first power conditioner 10 controls the first forward flow threshold and obtains the reference threshold that is the second forward flow threshold of the second power conditioner 20 will be described in detail.

  FIG. 4 is a first forward flow threshold control flow according to the present invention, and FIG. 5 is a diagram showing a change in output by the first forward flow threshold control. In the first forward flow threshold control, the first power conditioner 10 controls the output of the first power supply device 11 so that the forward flow higher than the first forward flow threshold matches the first forward flow threshold, and then the forward flow. Is higher than the first forward flow threshold, the first forward flow threshold is increased. In addition, the 2nd power conditioner 20 shall perform the conventional output control of FIG.

  The first power conditioner 10 performs conventional output control in the same manner as the second power conditioner 20 during the states T1 to T4 in FIG. This is because, after controlling the forward flow to the first forward flow threshold, the forward flow again becomes higher than the first forward flow threshold, in addition to the difference in the forward flow threshold with the second power conditioner 20. This is because various factors such as a decrease in the output of the power conditioner 2 and an increase in power consumption of the general load can be considered. It is also possible to switch to the first forward flow threshold control flow according to the setting of the administrator or the like at the time of initial setting of the distributed power supply system.

  The first power conditioner 10 determines that the second forward power flow threshold of the second power conditioner 20 is different from its first forward power flow threshold at the time of the state T5 from the periodicity of the forward power flow change. Then, the processing is switched to the first forward flow threshold control flow shown in FIG. In addition, what is necessary is just to perform acquisition of information, such as the periodicity of the change of a forward flow mentioned above, in the control part of the 1st power conditioner 10. FIG. The first power conditioner 10 measures the forward flow by the first current sensor 12 (step S201), and the forward flow 30W is higher than the first forward flow threshold 22W (Yes in step S202). The threshold value is increased to 26 W, for example (step S203). Further, the first power conditioner 10 confirms whether or not the output adjustment of the first power supply device 11 is necessary (Yes in step S204). Whether or not output adjustment is necessary is determined by determining whether or not output adjustment is necessary to set the first forward flow threshold of the first power conditioner 10 to the same value as the forward flow value. Next, the first power conditioner 10 increases the difference by 4W so that the forward flow 30W becomes the same value as the first forward flow threshold 26W after the threshold is increased (step S205). The processing of the second power conditioner 20 in the state T6 is the same as the flow shown in FIG.

  Here, the correction value by which the first power conditioner 10 increases the first forward flow threshold can be determined based on the difference between the forward flow and the current first forward flow threshold. For example, when the difference between the forward tide and the current first forward tide threshold is directly set as the correction value, there is a possibility that the same forward tide threshold as the second power conditioner 20 can be quickly set. Further, the value obtained by dividing the difference between the forward tide and the current first forward tide threshold into a plurality of values is used as a correction value, and the first forward tide threshold is increased stepwise, thereby causing a sudden change in the first forward tide threshold. It is possible to set the same forward power flow threshold as that of the second power conditioner 20 while preventing output fluctuation. When the first forward flow threshold is increased step by step, it is not necessary to equalize the correction values at each step. For example, by increasing the correction value in the first half and gradually decreasing the correction value in the second half, In addition, it is possible to set the same forward flow threshold more accurately while approaching the forward flow threshold of the second power conditioner 20.

  At the time of state T7, the first power conditioner 10 measures the forward power flow using the first current sensor 12 (step S201), and the forward power flow 30W is higher than the first forward power flow threshold 26W (Yes in step S202). The own first forward flow threshold is increased to 30 W (step S203). In this case, in the first power conditioner 10, since the forward flow 30W is equal to the first forward flow threshold 30W after the threshold is increased, output adjustment is not necessary (No in step S204).

  After the state T8, since the first forward flow threshold of the first power conditioner 10 and the second forward flow threshold of the second power conditioner 20 are both 30 W equal to the forward flow, the first power conditioner 10 and The output of the second power conditioner 20 can be stabilized. For example, after increasing the first forward flow threshold, the first power conditioner 10 measures the forward flow with the first current sensor 12 in a state T9 in which the forward flow is equal to the first forward flow threshold (step S201). Then, it is detected that the forward flow 30W is equal to the first forward flow threshold 30W (No in step S202). In this case, the first power conditioner 10 stops increasing the forward flow threshold. The first power conditioner 10 stores the first forward flow threshold at this time as a reference threshold that is the second forward flow threshold of the second power conditioner 20. The reference threshold value is stored in, for example, a storage unit provided in the first power conditioner 10.

  FIG. 6 is a second forward flow threshold control flow according to the present invention, and FIG. 7 is a diagram showing a change in output by the second forward flow threshold control. In the second forward flow threshold control, the first power conditioner 10 controls the output of the first power supply device 11 so that the forward flow higher than the first forward flow threshold matches the first forward flow threshold, and then the forward flow. Is higher than the first forward flow threshold, the first forward flow threshold is increased. Furthermore, after increasing the first forward flow threshold, the first power conditioner 10 decreases the first forward flow threshold when the forward flow is lower than the first forward flow threshold. In addition, the 2nd power conditioner 20 shall perform the conventional output control of FIG. Moreover, the 1st power conditioner 10 performs the conventional output control similarly to the 2nd power conditioner 20 between the states T1-T5 of FIG. 7 similarly to 1st Embodiment.

  The first power conditioner 10 determines that the second forward power flow threshold of the second power conditioner 20 is different from its first forward power flow threshold at the time of the state T5 from the periodicity of the forward power flow change. Then, the process is switched to the second forward flow threshold control flow shown in FIG. The first power conditioner 10 measures the forward flow by the first current sensor 12 (step S301), and the forward flow 30W is higher than the first forward flow threshold 22W (Yes in step S302). The threshold value is increased to 28 W, for example (step S303). Further, the first power conditioner 10 confirms whether or not the output adjustment of the first power supply device 11 is necessary (Yes in step S304), and the forward flow 30W becomes the same value as the first forward flow threshold 28W after the threshold is increased. In this way, the output for 2 W of the difference is increased (step S305). The processing of the second power conditioner 20 in the state T6 is the same as the flow shown in FIG.

  At the time of state T7, the first power conditioner 10 measures the forward flow by the first current sensor 12 (step S301), and the forward flow 30W is higher than the first forward flow threshold 28W (Yes in step S302). The own first forward flow threshold is increased to 34 W (step S303). Further, the first power conditioner 10 confirms whether or not the output adjustment of the first power supply device 11 is necessary (Yes in step S304), and the forward flow 30W becomes the same value as the first forward flow threshold 34W after the threshold is increased. In this manner, the output for the difference of 4 W is reduced (step S305). The processing of the second power conditioner 20 in the state T8 is the same as the flow shown in FIG.

  At the time of state T9, the first power conditioner 10 measures the forward power flow using the first current sensor 12 (step S301), and the forward power flow 30W is lower than the first forward power flow threshold 34W (No in step S302, step In S306, the first forward power flow threshold value is decreased to 32 W (Step S307). Further, the first power conditioner 10 confirms whether or not the output adjustment of the first power supply device 11 is necessary (Yes in step S304), and the forward flow 30W becomes the same value as the first forward flow threshold 32W after the threshold is decreased. In this way, the output for 2W of the difference is reduced (step S305). The processing of the second power conditioner 20 in the state T10 is the same as the flow shown in FIG.

  At the time of the state T11, the first power conditioner 10 measures the forward flow by the first current sensor 12 (step S301), and the forward flow 30W is lower than the first forward flow threshold 32W (No in step S302, step) In S306, the first forward power flow threshold is decreased to 30 W (step S307). In this case, in the first power conditioner 10, since the forward flow 30W is equal to the first forward flow threshold 30W after the threshold is increased, output adjustment is not necessary (No in step S304).

  After the state T12, since the first forward flow threshold of the first power conditioner 10 and the second forward flow threshold of the second power conditioner 20 are both 30 W equal to the forward flow, the first power conditioner 10 and The output of the second power conditioner 20 can be stabilized. For example, the first power conditioner 10 measures the forward power flow by the first current sensor 12 in the state T13 in which the forward power flow becomes equal to the first forward power flow threshold (step S301), and the forward power flow 30W becomes the first forward power flow threshold. It is detected that it is equal to 30 W (No in step S302, No in S306). In this case, the first power conditioner 10 stops decreasing the forward flow threshold. The first power conditioner 10 stores the first forward flow threshold at this time as a reference threshold that is the second forward flow threshold of the second power conditioner 20.

  The first power conditioner 10 performs output control of the first power supply system and the second power supply system using the reference threshold values obtained by the first and second forward power flow threshold control flows. When the second forward flow threshold of the second power supply system is known, the above-described forward flow threshold control flow can be omitted and the known second forward flow threshold can be used as the reference threshold.

  FIG. 8 is an output control flowchart according to the first embodiment of the present invention. In the output control according to the first embodiment, the first power conditioner 10 performs output control by periodically increasing / decreasing the first forward flow threshold with respect to the reference threshold. When the first power conditioner 10 increases its output (Yes in Step S401), the first power conditioner 10 decreases the first forward flow threshold from the reference threshold (Step S402). Thereby, the output of the 1st power conditioner 10 with a low forward power flow threshold value increases, and the output of the 2nd power conditioner 20 can be suppressed. Further, when increasing the output of the second power conditioner 20 (No in step S401), the first power conditioner 10 increases the first forward flow threshold value from the reference threshold value (step S403). Thereby, the output of the 2nd power conditioner 20 with a low forward power flow threshold value increases, and the output of the 1st power conditioner 10 can be suppressed.

  FIG. 9 is a diagram illustrating a change in output by the output control according to the first embodiment. As illustrated, according to this output control, the first power conditioner 10 can periodically switch the output of each power supply system. For example, the first power conditioner 10 can increase or decrease the first forward flow threshold value on a daily basis and shift the outputs of the first power supply system and the second power supply system. Load fluctuations (discharge amount) in homes and offices are large in terms of time, but are evenly uniform in terms of days. Therefore, the output of each distributed power system is almost equal by increasing or decreasing the forward flow threshold value on a daily basis. It becomes possible.

  In addition, for example, the first power conditioner 10 can increase or decrease the first forward flow threshold in units of time such as a few seconds, and can shift the outputs of the first power supply system and the second power supply system. Load fluctuations (discharge amount) in homes and offices are large in terms of time, but by distributing the output by increasing / decreasing the forward power flow threshold in fine time units, the output of each distributed power system can be made almost equal. It becomes.

  As described above, the first power conditioner 10 uses the second forward flow threshold for preventing reverse power flow of the second power conditioner 20 as a reference threshold, and uses the first forward flow threshold of the first power conditioner 10 as a reference threshold. It can be increased or decreased. As a result, it is possible to switch the power supply system in which the outputs are concentrated, and it is possible to eliminate the output bias of each power supply system. In addition, it is possible to prevent deterioration of SOH (State of Health) due to output concentration, and to suppress the life difference between the power supply systems. Furthermore, according to this embodiment, if the control for periodically increasing / decreasing the first forward flow threshold of the first power conditioner 10 with respect to the reference threshold is performed, it is possible to further suppress the life difference between the power supply systems.

  FIG. 10 is an output control flowchart according to the second embodiment of the present invention. In the output control according to the second embodiment, the first power conditioner 10 increases or decreases the first forward flow threshold with respect to the reference threshold so that the output from the first power supply device 11 becomes a predetermined output. The first power conditioner 10 confirms its own output (step S501). If the output is less than the predetermined output, the first forward flow threshold is decreased from the reference threshold, and if the output is higher than the predetermined output. The first forward flow threshold is increased from the reference threshold (steps S502 to S505). As described above, when the first forward flow threshold is lower than the reference threshold, the output of the first power conditioner 10 is increased. When the first forward flow threshold is higher than the reference threshold, the output of the first power conditioner 10 is decreased. Will do. Thereafter, the first power conditioner 10 confirms its own output again (step S501), and when its own output becomes equal to the predetermined output (Yes in step S502), the first forward flow threshold is set as a reference threshold ( Step S506). Thereby, the output of each distributed power supply system is stabilized.

  FIG. 11 is a diagram illustrating a change in output by the output control according to the second embodiment. As illustrated, according to this output control, the first power conditioner 10 can continuously perform a predetermined output. For example, when the total load capacity of the general load 30 is known, the first power conditioner 10 discharges half of the total load capacity, so that the output of each distributed power supply system can be made equal.

  Thus, according to the present embodiment, the first power conditioner 10 uses the second forward power flow threshold for preventing reverse power flow of the second power conditioner 20 as a reference threshold, and the output of the first power supply device 11 is predetermined. The first forward flow threshold is increased or decreased with respect to the reference threshold so as to be output. Thereby, without concentrating the output burden on any of the power supply systems, it is possible to eliminate the uneven output of each power supply system and to suppress the life difference. For example, it is possible to extend the life of each power supply system by performing output control within a range in which the SOH (State of Health) of each power supply device of the first power conditioner 10 and the second power conditioner 20 is not easily deteriorated. Become.

  Although the present invention has been described based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each functional unit, each step, etc. can be rearranged so that there is no logical contradiction, and a plurality of functional units, steps, etc. can be combined into one or divided. It is.

  For example, in the above-described embodiment, the first power supply system and the second power supply system have been described as the storage battery system. However, the present invention is not limited to this, and the present invention is not limited to this. Applicable.

DESCRIPTION OF SYMBOLS 10 1st power conditioner 11 1st power supply device 12 1st current sensor 20 2nd power conditioner (other power conditioners)
21 Second power supply (other power supply)
22 Second current sensor (other current sensor)
30 General load 40 Specific load 50 Changeover switch

Claims (6)

A power conditioner that controls the output of the power supply;
A current sensor connected to the inverter;
With other inverters that control the output of other power supplies,
Another current sensor connected to the other power conditioner,
When the current sensor and the other current sensor are installed at a position where the current from the system is detected as the same forward flow,
The power conditioner uses another forward power flow threshold for preventing reverse power flow of the other power conditioner as a reference threshold,
The distributed power supply system which increases / decreases a forward power flow threshold for preventing a reverse power flow of the power conditioner with respect to the reference threshold.   The distributed power supply system according to claim 1, wherein the power conditioner periodically increases or decreases a forward power flow threshold value for preventing reverse power flow of the power conditioner with respect to the reference threshold value.   3. The power conditioner according to claim 1, wherein the power conditioner increases or decreases a forward power flow threshold for preventing a reverse power flow of the power conditioner with respect to the reference threshold so that an output of the power supply device becomes a predetermined output. Distributed power system. A power conditioner that is connected to a current sensor and controls the output of the power supply device, and is connected to the same system as other power conditioners,
When the current sensor and the current sensor of the other power conditioner are installed at a position where the current from the system is detected as the same forward flow,
The other forward power flow threshold for preventing reverse power flow of the other power conditioner is set as a reference threshold,
A power conditioner comprising a controller that increases or decreases a forward power flow threshold value for preventing reverse power flow of the power conditioner with respect to the reference threshold value.   The power conditioner according to claim 4, wherein the controller periodically increases or decreases the forward flow threshold with respect to the reference threshold.   The power conditioner according to claim 4 or 5, wherein the control unit increases or decreases the forward flow threshold with respect to the reference threshold so that an output of the power supply device becomes a predetermined output.

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