Distributed power supply system

Abstract

To provide a technology for integrally operating a plurality of distributed power supply systems in conjunction with each other.SOLUTION: A distributed power supply system that is interconnected with a commercial power system and supplies power to a load, the distributed power supply system comprising: a first power supply system including a first storage battery and a first power conditioner; a second power supply system including a second storage battery and a second power conditioner; and an operation control for performing at least one of first operation control for charging and discharging the first storage battery and the second storage battery in accordance with a preset priority order or second operation control for transferring power between the first storage battery and the second storage battery; And a controller configured to instruct the first power conditioner and the second power conditioner to perform operation control.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a distributed power system. [Background technology]

[0002] In recent years, a variety of distributed power supply systems have become popular as distributed power supply systems that are operated in conjunction with a commercial power grid, such as photovoltaic (PV) systems and vehicle-to-home (V2H) systems that connect storage batteries for driving power in electric vehicles to the electrical system of a facility. Furthermore, multiple such distributed power supply systems are sometimes used in parallel (see, for example, Patent Document 1).

[0003] Incidentally, even when a plurality of distributed power generation systems are installed side by side as described in Patent Document 1, each system is operated as an independent system, and therefore each distributed power generation system is operated according to the circumstances. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-050292 Summary of the Invention [Problem to be solved by the invention]

[0005] For this reason, when each distributed power supply system has a storage battery as a power source, it is not possible to set a priority for charging and discharging. For example, in a system having a storage battery of an electric vehicle provided in a V2H system and a storage battery of a PV system as distributed power supplies, even if a user had a desire to prioritize charging the storage battery of the electric vehicle while the electric vehicle was connected, or to prioritize discharging from the storage battery of the PV system when discharging, this could not be realized. Furthermore, it was not possible to operate the system by interchange of power between multiple storage batteries.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a technology that enables multiple distributed power systems to be linked and operated in an integrated manner. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following configuration as one aspect. A distributed power system that is connected to a commercial power grid and supplies power to a load, a first power supply system including a first storage battery and a first power conditioner; a second power supply system including a second storage battery and a second power conditioner; a control unit that commands operation control to the first power conditioner and the second power conditioner according to operation conditions related to at least one of a first operation control that charges and discharges the first storage battery and the second storage battery in accordance with a preset priority order, and a second operation control that interchanges power between the first storage battery and the second storage battery; A distributed power generation system having the above features.

[0008] It should be noted that storage batteries as distributed power sources also include storage batteries that can be attached to or detached from the system, such as storage batteries for electric vehicles in a V2H system. With this configuration, based on commands from the control unit, a power conditioning system (PCS) provided in each power supply system controls charging and discharging of each storage battery according to a desired priority, and power can be exchanged between the storage batteries. In other words, when multiple distributed power generation systems, each equipped with a storage battery, are operated side by side, they can be linked and operated as an integrated system.

[0009] Further, the control unit includes a first controller corresponding to the first power conditioner and a second controller corresponding to the second power conditioner, the first controller and the second controller being communicatively connected; The first controller and the second controller may be configured to hold operating conditions relating to at least either the first operational control or the second operational control and transmit them to the other.

[0010] With this configuration, even when a new distributed power supply system is installed in addition to an existing distributed power supply system, the present invention can be applied by making use of the existing distributed power supply system.

[0011] The distributed power system further includes a power measurement unit that measures power at a receiving point from the commercial power system, the first power conditioner and the second power conditioner perform charge / discharge control of the first storage battery and the second storage battery so that the power receiving point power reaches the respective control target values; The operating conditions related to the discharge of the first operating control may include setting the control target value of one of the first storage battery and the second storage battery, whichever prioritizes discharge, to be closer to reverse flow than the control target value of the other storage battery.

[0012] The first power supply system and the second power supply system may each have a power measurement unit, or only one of the systems may have a power measurement unit and transmit the measurement value to the other system, or the control unit may have a power measurement unit.

[0013] Also, "leaning toward reverse flow" indicates a relative reverse flow direction when comparing the control target values ​​of the power receiving point of each power supply system. For example, if the power receiving point power value is a positive number with 0W as the boundary, which indicates reverse flow, and the control target values ​​of two power supply systems are 100W and 200W, respectively, the control target value of 200W will be leaning toward reverse flow, and if the power supply system with a control target value on the smooth flow side is -100W and -200W, the control target value of -100W will be leaning toward reverse flow.

[0014] With this configuration, in controlling the discharge of each storage battery, the power conditioner that prioritizes discharge starts discharging at a point when the amount of power purchased from the commercial power grid is less than that of the other power conditioner (i.e., earlier). During this discharge, the power at the receiving point is maintained closer to the reverse power flow than the control target value of the other power conditioner, so that the other storage battery does not discharge. This allows prioritization of discharge among the storage batteries in multiple systems. Furthermore, even in a configuration with a third or subsequent power supply system and storage battery, this can be achieved by setting the control target value of each closer to the reverse power flow according to the priority.

[0015] The distributed power system further includes a power measurement unit that measures power at a receiving point from the commercial power system, the first power conditioner and the second power conditioner perform charge / discharge control of the first storage battery and the second storage battery so that the power receiving point power reaches the respective control target values; The operating conditions related to charging of the first operating control may include setting the control target value of one of the first storage battery and the second storage battery, whichever is given priority for charging, to be closer to forward flow than the control target value of the other storage battery.

[0016] Here, "proximate to forward flow" refers to a relative forward flow direction when comparing the control target values ​​of the power receiving point power of each power supply system. For example, if the power receiving point power value is a positive value with 0 W as the boundary, and the power receiving point power is reverse flow, if the control target values ​​of the two power supply systems are 100 W and 200 W, respectively, the control target value of 100 W will be proximate to forward flow. If the power supply system with the control target value on the proximate side is -100 W and -200 W, the control target value of -200 W will be proximate to forward flow. With this configuration, in controlling the charging of each storage battery, the power conditioner with priority for charging starts charging when it purchases more power from the commercial power grid than the other power conditioner. During charging, the power receiving point power is maintained more proximate to forward flow than the control target value of the other power conditioner, so the other storage battery is not charged. This allows for prioritizing the charging of storage batteries in multiple systems. Furthermore, even in a configuration having a third or subsequent power supply system and storage battery, it is possible to deal with this by setting the respective control target values ​​closer to the forward flow in accordance with the priority order.

[0017] In addition, the operating conditions related to the second operating control may include charging one of the first storage battery and the second storage battery, whichever is the recipient of the power exchange, so as to keep the power supplied from the commercial power system below a predetermined value.

[0018] Specifically, power interchange between the storage batteries can be achieved, for example, by operating the first storage battery in a discharge mode and the second storage battery in a charge mode. If the power supply to the load is insufficient as a result of using all of the discharged power of the first storage battery or the charging power (e.g., rated input) required by the second storage battery to charge the second storage battery, the corresponding amount of power will have to be purchased from the commercial power grid, which may result in economic inefficiency. In this regard, with the above-described configuration, charging of the storage battery at the interchange destination is performed within a range in which the purchased power does not exceed a predetermined value, making it possible to interchange power in a manner that takes economic efficiency into account.

[0019] The distributed power system further includes a power measurement unit that measures power at a receiving point from the commercial power system, the first power conditioner and the second power conditioner perform charge / discharge control of the first storage battery and the second storage battery so that the power receiving point power reaches the respective control target values; The operating conditions for the second operating control may include setting the control target value for charging one of the first storage battery and the second storage battery that is the destination of power transfer to the predetermined value, and setting the control target value for discharging one of the first storage battery and the second storage battery that is the source of power transfer to be closer to the reverse flow than the predetermined value.

[0020] According to this, when the discharge power of the power receiving source is greater than the load consumption and the charge of the power receiving destination, discharge control is performed so that the power receiving point power is set to a control target value that is closer to reverse flow than a predetermined value. In this situation, if the power consumption of the load increases, for example, and the power consumption and charge amount exceeds the output of the discharge source, the purchased power increases, and the power receiving point power becomes closer to forward flow than the control target value of discharge. However, because the power receiving destination performs charge control at a predetermined value (the control target value of charge), the receiving destination reduces the charge power by the amount of power purchased in excess of the predetermined value. In other words, by setting a difference between the power control target values ​​of the power receiving point on the discharge side and the charge side, it is possible to seamlessly achieve control in which the charge amount increases when load consumption decreases and the charge amount decreases when load consumption increases.

[0021] Furthermore, the operating conditions related to the second operation control may include discharging one of the first storage battery and the second storage battery, which is a source of power interchange, so as to maximize the charged power of the one of the first storage battery and the second storage battery, which is a destination of power interchange. When power interchange between storage batteries is performed with priority given to time efficiency over economic efficiency, performing such control enables the most efficient charging of the power of the destination of power interchange.

[0022] In addition, the distributed power system may further have a power generation device, and the operating conditions related to the second operating control may include discharging, from the first storage battery or the second storage battery which is the source of power interchange, a value of power obtained by subtracting the power generated by the power generation device minus the power supplied to the load from the rated input value of the first storage battery or the second storage battery which is the destination of power interchange.

[0023] Here, the power generation device can be, for example, a solar power generation device, but is not limited to this and may be a power generation device using other renewable energy, a fuel cell, etc. With this configuration, when there is power generated by the power generation device, the generated power is used to consume the load and charge the storage battery of the transfer destination, and further, the shortfall in the charged power of the transfer destination is discharged from the storage battery of the transfer source, so that the power generated by the power generation device can be used to the maximum.

[0024] Furthermore, at least one of the first power conditioner and the second power conditioner may be a hybrid power conditioner that also controls the output power from the power generation device. Alternatively, a distributed power system having a third power supply system can be formed by providing a dedicated power conditioner for the power generation device as a third distributed power source. Furthermore, the first storage battery may be a storage battery mounted on an electric vehicle, and the first power supply system may include a charging / discharging stand connected to the electric vehicle. The present invention can be applied to distributed power supply systems with such various configurations.

[0025] The distributed power system may further include an input unit that accepts input operations related to setting the operating conditions. The input unit may be, for example, a dedicated operation panel (remote control) or a general-purpose information processing terminal with an application program installed. Note that the term "setting" here also includes the meaning of "changing." This allows the user to appropriately set desired operating conditions and utilize the distributed power system.

[0026] The present invention can be achieved by combining the above-described configurations and processes as long as no technical contradiction occurs. [Effects of the Invention]

[0027] According to the present invention, a plurality of distributed power systems can be linked and operated as an integrated unit. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic diagram showing the schematic configuration of a distributed power supply system according to an application example of the present invention. [Figure 2] FIG. 2 is a first diagram showing a schematic configuration of a distributed power supply system according to an embodiment of the present invention. [Figure 3] FIG. 3 is a second diagram showing a schematic configuration of a distributed power supply system according to an embodiment of the present invention. [Figure 4] FIG. 4 is a block diagram showing the functional configuration of the controller according to the embodiment of the present invention. [Figure 5] FIG. 5 is a third diagram showing a schematic configuration of a distributed power supply system according to an embodiment of the present invention. [Figure 6] FIG. 6 is a fourth diagram showing a schematic configuration of a distributed power supply system according to an embodiment of the present invention. [Figure 7] FIG. 7 is a flowchart showing an example of the flow of processing performed by the PCS according to the embodiment of the present invention. [Figure 8] FIG. 8 is a schematic diagram showing a schematic configuration of a distributed power supply system according to a first modified example of an embodiment of the present invention. [Figure 9] FIG. 9 is a schematic diagram showing a schematic configuration of a distributed power supply system according to a second modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] <Application example> (Overall configuration of the system related to the application example) The present invention can be applied to, for example, a distributed power system 9 equipped with a plurality of storage batteries as shown in Fig. 1. The distributed power system 9 according to this application example has a load L, is interconnected with a commercial power system P, and is equipped with a first power supply system 901 including a storage battery 91 and a power conditioner (PCS) 93 as distributed power sources, and a second power supply system 902 including a storage battery 92 and a PCS 94. The first power supply system 901 further includes an automatic switch 95 on its main circuit that switches between interconnected operation with the commercial power system P and stand-alone operation.

[0030] The storage batteries 91, 92 are connected to PCSs 93, 94, respectively, via a BMU (Battery Management Unit) not shown. Each of the PCSs 93, 94 is also communicatively connected to a control unit 90, and based on control commands sent from the control unit 90, each PCS performs power conversion between direct current (DC) and alternating current (AC) and controls input / output (charging and discharging). The control unit 90 can be, for example, an information processing terminal configured as a remote control panel, or a general-purpose information processing device can be adopted.

[0031] Since the first power supply system 901 and the second power supply system 902 are independent systems, conventionally the discharging and charging of the storage batteries in each system would have been controlled separately, making it difficult to meet needs such as prioritizing discharging from one storage battery.

[0032] (Features of this system) In this regard, according to the distributed power supply system 9 of this application example, the control unit 90 generates control commands based on operating conditions for operating each power supply system in conjunction with one another and transmits them to each PCS 93 and 94, and the PCSs 93 and 94 perform charge and discharge control of the storage batteries 91 and 92 in accordance with the control commands, thereby making it possible to operate different power supply systems (distributed power supplies) as if they were a single power supply system.

[0033] This makes it possible to give priority to discharging (or charging) one of the multiple storage batteries. A specific method for this is explained below. First, when it is desired to give priority to discharging from storage battery 91, the control target value for discharging storage battery 91 is set closer to reverse power flow than the control target value for discharging storage battery 92, and each of PCSs 93 and 94 performs control in accordance with this control target value. The target value used as an index for control is the power receiving point power. The value of the power receiving point power is measured by a power meter (not shown) placed at the most upstream of the main circuit and is provided to each of PCSs 93 and 94.

[0034] (Example of charging / discharging priority setting using this system) As an example, if the value of the power receiving point power is a positive value with respect to 0 W, it is determined that the state is a reverse power flow state, and the control target value of PCS93 is set to -100 W, and the control target value of PCS94 is set to -200 W. In this case, storage battery 91, whose control target value is set closer to the reverse power flow side, discharges toward the control target value, and the discharge power from storage battery 92, whose control target value is set closer to the forward power flow side, is reduced (stopped). As a result, storage battery 91 discharges preferentially until the SOC (State Of Charge) of storage battery 91 drops and it can no longer discharge to maintain the control target value, and the power receiving point power drops below -200 W, which is the discharge control target value of storage battery 92. When the current becomes even smaller (toward the forward flow side), the storage battery 92 starts discharging.

[0035] In other words, by setting operating conditions that provide differences in the control target values ​​for charging and discharging between each power supply system 901 and 902, and performing control based on these in each PCS 93, 94, it becomes possible to prioritize the charging and discharging of storage batteries between different power supply systems and operate them as a single distributed power supply system 9.

[0036] <Embodiment> (Overall system configuration) Next, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 2 is a schematic diagram showing the general configuration of a distributed power system 1 according to this embodiment. As shown in Fig. 2, the distributed power system 1 is equipped with a load L, is connected to a commercial power system P, and includes two distributed power systems: a V2H system 19 and a PV-energy storage system 29. Note that the load L may include not only a general load but also a specific load.

[0037] The V2H system 19 includes an EV storage battery 11 that is mounted on an electric vehicle (EV) and stores electricity as a power source for the EV, a V2H stand 12, an EVPCS 10, a controller 100, and a power meter 13. In addition, an automatic switch 14 is provided on the main circuit to switch the V2H system 19 between grid-connected operation with the commercial power system P and stand-alone operation.

[0038] The PV-storage system 29 includes a PV device 21 (for example, a string consisting of multiple solar panels), a PV storage battery 22, a hybrid PCS 20, a controller 200, and a power meter 23. In addition, an automatic switch 24 is provided on the main circuit to switch the PV-storage system 29 between grid-connected operation and stand-alone operation.

[0039] (About the V2H system) The EV storage battery 11 is detachably connected to the EVPCS 10 via a V2H stand 12. Figure 3 shows the configuration of the distributed power system 1 in a state where the EV storage battery 11 is detached while the EV is in use, etc. The EVPCS 10 performs AC / DC conversion and voltage step-up / step-down of power, and also controls the charging and discharging (input and output of power) of the EV storage battery 11 according to control commands from the controller 100 and the value of the power receiving point measured by the power meter 13.

[0040] The controller 100 is, for example, an information processing terminal having a gateway function as hardware, and is communicatively connected to a controller 200 of the PV-electricity storage system 29 via a communication line C. FIG. 4 is a block diagram showing the functional configuration of the controller 100. As shown in FIG. 4, the controller 100 has a storage unit 110, a communication unit 101, and a control command generation unit 102.

[0041] The storage unit 110 stores various operating conditions of the EVPCS 10 and the hybrid PCS 20 related to the charging and discharging of the EV storage battery 11 and the PV storage battery 22, in order to operate the V2H system 19 and the PV-storage system 29 in an integrated manner in cooperation with each other. Each operating condition will be described in detail later.

[0042] The communication unit 101 is a functional unit that communicates with external devices in accordance with various communication standards not limited to the communication line C, and communicates with not only the EVPCS 10 and the controller 200, but also with an information processing terminal 300 owned by the user via an external communication network N.

[0043] The control command generating unit 102 generates a control command for the EVPCS 10 based on the driving conditions designated by the user input through the information processing terminal 300. is transmitted to the EVPCS 10 via the communication unit 101.

[0044] (PV-storage system) The PV-storage system 29 includes two distributed power sources, a PV device 21 and a PV storage battery 22, both of which are connected to the hybrid PCS 20. The hybrid PCS 20 performs AC / DC conversion and voltage step-up / step-down of power, and also controls the output of the PV device 21 and the charging / discharging of the PV storage battery 22 according to control commands from the controller 200 and the value of the power receiving point power measured by the power meter 23.

[0045] The controller 200 is, for example, an information processing terminal equipped with a gateway function as hardware, and is communicatively connected to the controller 100 of the V2H system 19 via a communication line C. The controller 200 does not store the operating conditions in long-term memory itself, but acquires the operating conditions transmitted from the controller 100 and generates control commands for the hybrid PCS 20 according to the acquired operating conditions. The generated control commands are transmitted to the hybrid PCS 20.

[0046] (Operating conditions) Next, we will explain the operating conditions related to the charge / discharge control of the EV storage battery 11 and the PV storage battery 22 in this embodiment. The operating conditions are set by a user using, for example, the information processing terminal 300, and are stored in the storage unit 110 of the controller 100. However, default operating conditions may also be stored at the time of factory shipment.

[0047] The operating conditions in this embodiment can be classified into discharge priority conditions 111 relating to the priority of discharge when connected to the commercial power system P, charge priority conditions 112 relating to the priority of charge when connected to the commercial power system P, time-priority power interchange conditions 113 and economy-priority power interchange conditions 114 relating to the interchange of power between storage batteries when connected to the commercial power system P, and power outage discharge conditions 115, power outage charge conditions 116, and power outage power interchange conditions 117 relating to the charge and discharge control of each storage battery in an autonomous operation state such as during a power outage.

[0048] (When prioritizing discharge) The discharge priority condition 111 is an operating condition for discharging the power consumed by the load L from the EV storage battery 11 or the PV storage battery 22 in an arbitrary order of priority. When the PV device 21 is generating power, the power generated by the PV device 21 has the highest priority for supplying power to the load L, and therefore, the power that cannot be supplied by the power generated by the PV device 21 is discharged in accordance with the order of priority.

[0049] For example, if priority is given to discharging EV storage battery 11, the control target value of the power receiving point when EVPCS 10 is discharging is set closer to reverse power flow than the control target value of the power receiving point when hybrid PCS 20 is discharging. As an example, if a positive value of the power receiving point power is considered to be in a reverse power flow state (the following description in this specification will be based on this assumption), the control target value of EVPCS 10 is set to -100 W, and the control target value of hybrid PCS 20 is set to -200 W.

[0050] Conversely, if it is desired to prioritize discharging from PV storage battery 22, the control target value of the power receiving point during discharging of hybrid PCS 20 is set closer to the reverse power flow than the control target value of the power receiving point during discharging of EVPCS 10. For example, the control target value of hybrid PCS 20 is set to −100 W, and the control target value of EVPCS 10 is set to −200 W.

[0051] (When prioritizing charging) The charging priority condition 112 is an operating condition for charging the EV storage battery 11 or the PV storage battery 22 in an arbitrary order of priority. Note that there are cases where surplus power (only) generated by the PV device 21 is used as the power source for charging, and cases where purchased power (nighttime power, etc.) from the commercial power system P is used. Here, when purchased power is used, it is not necessary to simply select which storage battery is used. The batteries are charged sequentially with the rated input power based solely on the priority setting, and charging control is stopped when the target SOC is reached. For this reason, the following describes the case where charging is performed using only surplus power (hereinafter referred to as surplus charging).

[0052] For example, when charging the EV storage battery 11 with priority, the control target value of the power receiving point when the EVPCS 10 is charging is set closer to the forward flow than the control target value of the power receiving point when the hybrid PCS 20 is discharging. As an example, the control target value of the EVPCS 10 is set to 0 W, and the control target value of the hybrid PCS 20 is set to 100 W (reverse flow state).

[0053] Conversely, if priority is given to charging the PV storage battery 22, the control target value of the power receiving point during charging of the hybrid PCS 20 is set closer to the forward flow than the control target value of the power receiving point during discharging of the EVPCS 10. For example, the control target value of the hybrid PCS 20 is set to 0 W, and the control target value of the EVPCS 10 is set to 100 W.

[0054] Following the example above, the operation of prioritizing charging of the EV battery 11 will be described. When the power receiving point is controlled to 0 W, the hybrid PCS 20's control target value is set to the reverse power flow side, so the charging power to the PV battery 22 decreases and the hybrid PCS 20 control shifts to discharge control. However, because the control target value for the hybrid PCS 20's discharge control (-100 W or -200 W in the example above) is set closer to the forward power flow than the power receiving point power (0 W), the hybrid PCS 20 control immediately shifts from discharge to charge. Then, because the control target value for charge control is closer to the reverse power flow than the power receiving point power, the hybrid PCS 20 control shifts back to discharge control. In this way, the power supply system with the lower charging priority repeatedly shifts between charge control and discharge control, thereby stopping charging and discharging of the lower-priority battery, thereby realizing priority charging of the higher-priority battery. This mechanism of prioritizing is also applicable to operating conditions when prioritizing discharging.

[0055] (When power interchange is performed) The time-priority power interchange condition 113 is an operating condition for interchange (supply) of power from one of the EV storage battery 11 or the PV storage battery 22 to the other, and is an operating condition for minimizing the time until a target SOC is reached. Specifically, discharge control is performed on the storage battery at the interchange source, and charge control is performed on the storage battery at the interchange destination. The interchange of power between the storage batteries ends when the SOC of the storage battery at the interchange destination reaches an upper threshold (target charge value) or when the SOC of the storage battery at the interchange source reaches a lower threshold.

[0056] If there is power generated from the PV device 21 and load consumption is greater than the generated power, the load consumption that cannot be covered by power generation is purchased from the commercial power system P, and the discharged power of the interchange source becomes equal to the charged power of the interchange destination. Also, if the generated power is greater than the load consumption, the discharged power of the interchange source becomes equal to the value obtained by subtracting load consumption from the generated power and subtracting the value obtained by subtracting the charged power of the interchange destination.

[0057] The economically prioritized power interchange condition 114 is an operating condition for interchange (supply) of power from one of the EV storage battery 11 or the PV storage battery 22 to the other, and is an operating condition for keeping the amount of power purchased from the commercial power grid P below a predetermined value. Discharge control is performed on the storage battery at the source of the interchange, and charge control is performed on the storage battery at the destination of the interchange. Power interchange between the storage batteries ends when the SOC of the storage battery at the destination of the interchange reaches an upper threshold or when the SOC of the storage battery at the source of the interchange reaches a lower threshold.

[0058] In this case, for example, if the control target value for the discharge control of the power source is set to -100 W and the control target value for the charge control of the power source is set to -200 W, the following operation will occur. If the original discharge power is greater than the sum of the load consumption and the charging power of the transfer destination minus the PV generation power, the power receiving point is controlled to -100W. If, under these conditions, load consumption increases or PV generation decreases, causing the power consumption side's power to increase and exceed the transfer source's discharge power, the power receiving point power value becomes smaller than the discharge control target value (i.e., the purchased power increases from 100W). However, because the transfer destination performs charging control with a control target value of -200W, the transfer destination will reduce the charging power if the purchased power exceeds 200W. In this way, by creating a difference between the transfer source's discharge control target value and the transfer destination's charge control target value, it is possible to seamlessly increase the charging amount during low loads and decrease the charging amount during high loads.

[0059] (System during power outages) In this embodiment, in the event of a power outage in which the power supply from the commercial power grid P is cut off, if the EV storage battery 11 is connected to the system and has remaining capacity (i.e., SOC > lower limit threshold), the V2H system 19 starts autonomous operation. The configuration of the distributed power system 1 in this state is shown in Figure 5.

[0060] Furthermore, when the V2H system 19 is operating autonomously, the PV-storage system 29 performs pseudo-grid-connected operation with respect to the V2H system 19. Specifically, the hybrid PCS 20 acquires information on the output power value (EV output value) from the EV storage battery 11 via communication line C, and uses the acquired EV output value instead of the power receiving point power as a control index to perform charge / discharge control so that the EV output value reaches a control target value. Note that at this time, the hybrid PCS 20 prevents errors from occurring by ignoring the information on the measurement value from the wattmeter 23 (by performing masking processing, for example).

[0061] If the EV storage battery 11 is not connected to the system during a power outage, or if the EV storage battery 11 is connected but its SOC has reached its lower limit, the PV-storage system 29 will operate autonomously. The configuration of the distributed power supply system 1 in this state is shown in Figure 6.

[0062] (Charging and discharging operating conditions during a power outage) Among the operating conditions for power outages stored in the memory unit 110, the power outage discharge condition 115 determines the priority of discharge during a power outage when the power supply from the commercial power system P is cut off, and is an operating condition under which, while one of the EV storage battery 11 and the PV storage battery 22 is discharging for a load power consumption amount that exceeds the power generation power of the PV device 21, the other stops charging and discharging. Note that which storage battery is given priority for discharge in this case can be determined by the discharge control target value set by the hybrid PCS 20 (for example, if the discharge control target value is <0 W, discharge from the EV storage battery 11 is given priority).

[0063] The power outage charging condition 116 determines the priority of charging during a power outage when the power supply from the commercial power system P is cut off, and is an operating condition in which, when the power generated by the PV device 21 exceeds the load power consumption, the surplus is used to charge either the EV storage battery 11 or the PV storage battery 22, and while one is charging, charging or discharging of the other is stopped. In this case, which storage battery is given priority for charging can be determined by the charge control target value set by the hybrid PCS 20 (for example, if the charge control target value is <0 W, charging to the PV storage battery 22 is given priority).

[0064] The power outage power interchange condition 117 is for interchange of power between the EV storage battery 11 and the PV storage battery 22 during a power outage when the power supply from the commercial power system P is cut off, and is an operating condition for charging the power interchange destination with the surplus power when the dischargeable power of the power interchange source exceeds the load power consumption. The operating condition requires the distinction between the interchange source and the interchange destination, as well as the SOC lower limit threshold of the interchange source battery and the SOC upper limit threshold of the interchange destination battery.

[0065] (Processing flow performed by PCS) Next, we will outline the processing flow related to the charge / discharge control of the storage battery performed by the EVPCS 10 and the hybrid PCS 20 in this embodiment. Figure 7 is a flowchart showing an example of the processing flow related to the charge / discharge control of the EV storage battery performed by the EVPCS 10. Note that although the following description focuses on the EVPCS 10, the hybrid PCS 20 also performs similar processing.

[0066] 7, first, EVPCS 10 acquires a control command from controller 100 (S101), and stores the operation mode (charging, discharging, power interchange, etc.) and the corresponding control target value according to the command as the subsequent operation conditions (S102). Next, EVPCS 10 acquires the value of the power receiving point power from power meter 13 (S103). The acquired value of the power receiving point power is transmitted to controller 100.

[0067] Next, the EVPCS 10 performs a process of determining whether a new control command has been acquired from the controller 100 (S104). If it is determined that a new control command has been acquired (for example, if there is a change in the operation mode due to a change in the power receiving point power value, a change in the SOC value, a forced charge / discharge instruction by the user, etc.), the process returns to step S102 and repeats the subsequent processes.

[0068] On the other hand, if it is determined in step S104 that a new control command has not been acquired, the EVPCS 10 controls the charging and discharging of the EV storage battery 11 based on the control target value saved in step S102 and the value of the power receiving point power acquired in step S103 (S105). Next, the EVPCS 10 determines whether a predetermined operation stop condition (e.g., reaching the SOC lower limit threshold, arrival of a standby schedule, etc.) is met (S106). If it is determined that the operation stop condition is not met, the process returns to step S103 and repeats the subsequent processes. On the other hand, if it is determined in step S106 that the operation stop condition is met, the EVPCS 10 stops operation and transitions to a standby state (S107), and the series of processes is temporarily terminated.

[0069] According to the distributed power system 1 of this embodiment, even when multiple distributed power systems each equipped with a storage battery are installed side by side, it is possible to control the charging and discharging of each storage battery in an interlocking manner, set priorities for charging and discharging, and share power between the storage batteries, thereby enabling the storage batteries (distributed power systems) to be operated in an integrated manner. Furthermore, since no special hardware configuration is required for such operation, the integrated operation of multiple distributed power systems can be easily performed. Furthermore, when a new distributed power system is added to an existing system, the integrated operation of multiple systems can be easily performed by changing the operating conditions held by the controller.

[0070] <Variation 1> The above-described embodiment is merely an example of an embodiment of the present invention, and the present invention is not limited to the above-described specific embodiment. Various modifications of the present invention are possible within the scope of the technical concept thereof. For example, in the above-described embodiment, the PV-storage system 29 includes a power meter 23 that measures the power receiving point power, and the hybrid PCS 20 acquires the power receiving point power value from the power meter 23. However, as shown in FIG. 8 , the configuration may be such that the power meter 23 is eliminated. FIG. 8 is a schematic diagram showing the general configuration of a distributed power system 2 according to a first modification. In the following description of the modification, the same components as those in the embodiment are denoted by the same reference numerals, and a detailed description thereof will be omitted. In the distributed power system 2 according to this modification, the V2H system 19 transmits the power receiving point power value acquired by the power meter 13 to the PV-storage system 29 via the communication line C, and the hybrid PCS 20 performs charge / discharge control using the transmitted power receiving point power value.

[0071] <Variation 2> Next, another modified example will be described with reference to FIG. 9 . As shown in FIG. 9 , in a distributed power system 3 according to this modified example, a PV-storage system 29 includes a power meter 26 for measuring the output power of the V2H system 19 during independent operation. Otherwise, the configuration is the same as that of the distributed power system 1 according to the embodiment. In the above-described embodiment, when the V2H system 19 performs independent operation during a power outage, the output power value of the EVPCS 10 is transmitted to the PV-storage system 29 via the communication line C. However, in this modified example, the PV-storage system 29 obtains the output power value of the EVPCS 10 using the power meter 26 and performs pseudo-grid-connected operation with respect to the V2H system 19 based on the obtained value. With this configuration, charge and discharge control can be performed without the time lag caused by the transmission of the output power value of the EVPCS 10.

[0072] <Other> The distributed power supply system according to the present invention can be applied to various variations other than the system configurations of the above examples. For example, the power generation device is not limited to a solar power generation device, but other renewable energy power generation devices or gas-based power generation devices can also be used. Furthermore, in addition to solar power generation, such power generation devices and corresponding power storage and PCS (including both hybrid and single-function types) can also be provided. Furthermore, a system configuration in which multiple distributed power supply systems using only storage batteries as distributed power sources can be installed side by side can also be used. Furthermore, as explained in the application examples, a system configuration in which one control unit controls multiple distributed power supply systems is naturally possible.

[0073] <Appendix 1> A distributed power system (1, 2, 3, 9) that is connected to a commercial power system (P) and supplies power to a load (L), a first power supply system (19, 901) including a first storage battery (11, 91) and a first power conditioner (10, 93); a second power supply system (902) including a second storage battery (22, 92) and a second power conditioner (20, 94); a control unit (100, 200, 90) that commands operation control to the first power conditioner and the second power conditioner according to an operation condition related to at least one of a first operation control that charges and discharges the first storage battery and the second storage battery in accordance with a preset priority order, and a second operation control that interchanges power between the first storage battery and the second storage battery; A distributed power system (1, 2, 3, 9) having:

[0074] <Appendix 2> the control unit (100, 200) includes a first controller (100) corresponding to the first power conditioner (10) and a second controller (200) corresponding to the second power conditioner (20), the first controller (100) and the second controller (200) being communicatively connected; an operating condition related to at least one of the first operation control and the second operation control is held by one of the first controller (100) and the second controller (200) and transmitted to the other; A distributed power system (1, 2, 3) as described in Appendix 1.

[0075] <Appendix 3> a power measurement unit (13, 23) that measures power at a receiving point from the commercial power system (P), The first power conditioner (10) and the second power conditioner (20) performing charge / discharge control of the first storage battery (11) and the second storage battery (12) so that the power at the receiving point reaches the respective control target values; the operating conditions related to the discharge of the first operation control include setting the control target value of one of the first storage battery (11) and the second storage battery (22) that is prioritized for discharge to be closer to a reverse power flow than the control target value of the other storage battery. A distributed power system (1, 2, 3) according to appendix 1 or 2.

[0076] <Appendix 4> a power measurement unit (13, 23) that measures power at a receiving point from the commercial power system (P), the first power conditioner (10) and the second power conditioner (20) perform charge / discharge control of the first storage battery (11) and the second storage battery (22) so that the power at the receiving point reaches the respective control target values; The operating conditions related to charging of the first operation control include setting the control target value of one of the first storage battery and the second storage battery, which is prioritized for charging, to be closer to a forward power flow than the control target value of the other storage battery. A distributed power system (1, 2, 3) according to any one of appendices 1 to 3.

[0077] <Appendix 5> the operating conditions related to the second operation control include charging one of the first storage battery (11) and the second storage battery (22), which is a power interchange destination, so as to suppress the power supplied from the commercial power grid to a predetermined value or less. A distributed power system (1, 2, 3) according to any one of appendices 1 to 4.

[0078] <Appendix 6> a power measurement unit (13, 23) that measures power at a receiving point from the commercial power system (P), the first power conditioner (10) and the second power conditioner (20) perform charge / discharge control of the first storage battery (11) and the second storage battery (22) so that the power at the receiving point reaches the respective control target values; The operation conditions for the second operation control include setting the control target value for charging one of the first storage battery (11) and the second storage battery (22), which is a power interchange destination, to the predetermined value, and setting the control target value for discharging one of the first storage battery (11) and the second storage battery (22), which is a power interchange source, to be closer to a reverse power flow than the predetermined value. A distributed power system (1, 2, 3) as described in Appendix 5.

[0079] <Appendix 7> The operating conditions related to the second operation control include discharging one of the first storage battery (11) and the second storage battery (22), which is a power interchange source, so as to maximize, as much as possible, the charged power of the one of the first storage battery (11) and the second storage battery (22), which is a power interchange destination. A distributed power system (1, 2, 3) according to appendix 1 to 4.

[0080] <Appendix 8> Further comprising a power generation device (21). A distributed power system (1, 2, 3) according to any one of appendices 1 to 7.

[0081] <Appendix 9> The operating condition for the second operation control is to set a value obtained by subtracting the power supplied to the load (L) from the power generated by the power generation device (21) to the first storage battery (11) or the second storage battery (12). (12) which is the power interchange destination, from the first storage battery (11) or the second storage battery (12) which is the power interchange source, the power of which value is subtracted from the rated input value of the first storage battery (11) or the second storage battery (12) which is the power interchange destination, A distributed power system (1, 2, 3) as described in Appendix 8.

[0082] <Appendix 10> At least one of the first power conditioner (10) and the second power conditioner (20) is a hybrid power conditioner (20) that also controls the output power from the power generation device (21). A distributed power system (1, 2, 3) according to appendix 8 or 9.

[0083] <Appendix 11> The first storage battery (11) is a storage battery mounted on an electric vehicle, and the first power supply system (19) includes a charging / discharging stand (12) connected to the electric vehicle. A distributed power system (1, 2, 3) according to any one of appendices 1 to 9.

[0084] <Appendix 12> Further comprising an input unit (300) that accepts input operations related to the setting of the operating conditions. 12. A distributed power system (1, 2, 3) according to any one of appendices 1 to 11. [Explanation of symbols]

[0085] 1, 2, 3, 9... Distributed Power Systems 10···EVPCS 11. EV battery 12···V2H Stand 13, 23, 26... Wattmeter 14, 24, 95...Automatic switch 19. V2H system 20 Hybrid PCS 21...PV equipment 22. PV battery 100, 200 controller 300···Information processing terminal 90 Control unit 91, 92... Storage battery 93, 94... PCS 901···First Power Supply System 902 Second Power Supply System P...Commercial power system L...Load C···Communication line N···Communication Network

Claims

1. A distributed power system that is connected to a commercial power grid and supplies power to a load, a first power supply system including a first storage battery and a first power conditioner; a second power supply system including a second storage battery and a second power conditioner; a control unit that commands operation control to the first power conditioner and the second power conditioner according to operation conditions related to at least one of a first operation control that charges and discharges the first storage battery and the second storage battery according to a preset priority order, and a second operation control that interchanges power between the first storage battery and the second storage battery; A distributed power system having:

2. the control unit includes a first controller corresponding to the first power conditioner and a second controller corresponding to the second power conditioner, the first controller and the second controller being communicatively connected; One of the first controller and the second controller is configured to hold operating conditions related to at least one of the first operation control and the second operation control and transmit them to the other. The distributed power system of claim 1 .

3. a power measurement unit that measures power at a receiving point from the commercial power system, the first power conditioner and the second power conditioner perform charge / discharge control of the first storage battery and the second storage battery so that the power receiving point power reaches the respective control target values; The operating condition related to the discharge of the first operation control includes setting the control target value of one of the first storage battery and the second storage battery, which has priority in discharging, to be closer to reverse power flow than the control target value of the other storage battery. The distributed power system of claim 1 .

4. a power measurement unit that measures power at a receiving point from the commercial power system, the first power conditioner and the second power conditioner perform charge / discharge control of the first storage battery and the second storage battery so that the power receiving point power reaches the respective control target values; the operating condition related to charging of the first operation control includes setting the control target value of one of the first storage battery and the second storage battery, which is given priority for charging, to be closer to a forward power flow than the control target value of the other storage battery, The distributed power system of claim 1 .

5. The operating condition related to the second operation control includes charging one of the first storage battery and the second storage battery, which is to be the power interchange destination, so as to keep the power supplied from the commercial power grid at or below a predetermined value. The distributed power system of claim 1 .

6. a power measurement unit that measures power at a receiving point from the commercial power system, the first power conditioner and the second power conditioner perform charge / discharge control of the first storage battery and the second storage battery so that the power receiving point power reaches the respective control target values; The operating conditions related to the second operation control include setting the control target value related to charging of one of the first storage battery and the second storage battery, which is a power interchange destination, to the predetermined value, and setting the control target value related to discharging of the one of the first storage battery and the second storage battery, which is a power interchange source, to be closer to reverse power flow than the predetermined value. The distributed power system of claim 5 .

7. The operating condition related to the second operation control is a condition in which one of the first storage battery and the second storage battery is discharging one of the first storage battery and the second storage battery that is a power interchange source so as to maximize the charged power of the other of the first storage battery and the second storage battery as much as possible; The distributed power system of claim 1 .

8. further comprising a power generation device; The distributed power system of claim 1 .

9. The operating condition related to the second operation control includes discharging, from one of the first storage battery and the second storage battery that is the power source, power of a value obtained by subtracting power supplied to the load from power generated by the power generation device from a rated input value of the first storage battery or the second storage battery that is the power source. The distributed power system of claim 8.

10. At least one of the first power conditioner and the second power conditioner is a hybrid power conditioner that also controls the output power from the power generation device. The distributed power system of claim 8.

11. the first storage battery is a storage battery mounted on an electric vehicle, and the first power supply system includes a charging / discharging stand connected to the electric vehicle. The distributed power system of claim 1 .

12. Further, an input unit that accepts an input operation related to the setting of the operating conditions is provided. A distributed power generation system according to any one of claims 1 to 11.

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