Distributed power supply system

Abstract

To provide a technique for enabling self-consumption control by a storage battery system and prioritization of a utilization power supply during a power failure in a power supply system including a plurality of distributed power supplies.SOLUTION: The distributed power source system includes a first power source system including a first storage battery, a first 1PCS, and a power meter that measures power at a power receiving point, a second power source system including a second storage battery and the first 2PCS, and a control unit that instructs the first 1PCS and the first 2PCS to perform operation control based on an operation condition set in advance, wherein the operation condition includes that the second storage battery is charged and discharged based on the power at the power receiving point and a control target value when the first power source system is grid-connected to the commercial power system in the first 2PCS, and the second storage battery is charged and discharged based on a power value from the first storage battery and the control target value when the first power source system performs an autonomous operation during a power failure in which power supply from the commercial power system is stopped.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 generation systems have become popular, including 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. Multiple such distributed power generation systems are also being used in parallel.

[0003] However, even when multiple distributed power systems are installed side by side, each system operates as an independent system. Therefore, in the event of a power outage, for example, when the power supply from the commercial power grid is cut off, it is not possible to prioritize and utilize the multiple distributed power sources, and each distributed power source will operate at its own pace.

[0004] In this regard, a technology has been proposed in which, during a power outage, one of multiple distributed power systems is operated independently, and the other distributed power systems are operated in a pseudo-grid-connected manner with respect to the independently operating distributed power system (e.g., Patent Documents 1 to 3).

[0005] However, in the above technology, if the distributed power system that performs pseudo-grid-connection operation is a storage battery, the main power will not flow during a power outage, and the measured value of the power receiving point will be 0 W, so the storage battery system cannot determine the direction of charging or discharging based on the power receiving point.Since the storage battery operates in either discharging or charging mode, the storage battery system cannot perform self-consumption operation, making it difficult to effectively utilize the storage battery during a power outage.

[0006] In order to solve this problem, it is conceivable to adopt a configuration such as that of a distributed power system 8 shown in Fig. 10. The distributed power system 8 is a power supply system that is interconnected with a commercial power system P and supplies power to a load L, and is configured to include a first power supply system 801 that has a storage battery 81 and a power conditioning system (PCS) 83, and a second power supply system that has a storage battery 82 and a PCS 83. The distributed power supply system 8 also includes power meters 87 and 88 that measure mains power.

[0007] The power meter 87 measures the power at the power receiving point and transmits the measured value to the PCS 83, so that the PCS 83 performs charge / discharge control toward a control target value using the power at the power receiving point as an index when the system is grid-connected. Meanwhile, the power meter 88 is disposed downstream of the switch 85 that switches the first power supply system 801 between grid-connected operation and standalone operation. The PCS 84 of the second power supply system 802 performs charge / discharge control toward a control target value using the measured value of the power meter 88 as an index. Here, because the power meter 88 measures the power downstream of the switch 85, even during a power outage, if the first power supply system 801 is operating in standalone operation, the second power supply system 802 can also perform self-consumption operation. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4101201 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-050292 [Patent Document 3] Patent No. 6415260 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the case of a configuration such as the distributed power system 8 described above, when a power supply system under contract that does not allow reverse power flow is connected to the commercial power system while the system is operating normally, the second power supply system 802 cannot supply power in excess of the power value measured by the power meter 88, which has the disadvantage that the range in which the storage battery 82 can supply power to the load L is narrowed.

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a technology that enables self-consumption control and prioritization of utilized power sources using a storage battery system in the event of a power outage in a power supply system that includes multiple distributed power sources. [Means for solving the problem]

[0011] 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, a first power conditioner, and a first wattmeter that measures power at a receiving point from the commercial power system; a second power supply system including a second storage battery and a second power conditioner; a control unit that commands operation control based on preset operating conditions to the first power conditioner and the second power conditioner, The operating conditions include that, when the second power conditioner is interconnected with the commercial power grid, the second power conditioner charges and discharges the second storage battery based on the power at the power receiving point and a control target value, and when the first power supply system performs independent operation during a power outage in which power supply from the commercial power grid is cut off, the second power conditioner charges and discharges the second storage battery based on an output power value from the first storage battery and the control target value. It is a distributed power generation system.

[0012] The first storage battery and the second storage battery also include storage batteries that are detachable from the system, such as storage batteries of electric vehicles in a V2H system. According to the above configuration, the second power supply system performs charge / discharge control that can make maximum use of the second storage battery based on the power at the receiving point when connected to the grid, and can also perform self-consumption operation using the power of the storage battery by performing quasi-grid-connected operation with respect to the output power of the first power supply system even during a power outage.

[0013] The first power supply system and the second power supply system may be communicatively connected via a communication means, and the output power value of the first storage battery during the stand-alone operation of the first power supply system may be transmitted to the second power conditioner via the communication means. With this configuration, the output value of the first storage battery can be easily used by the second power conditioner without adding any new hardware configuration.

[0014] The second power supply system further includes a second power meter that measures power at the power receiving point, When interconnected with 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 at the power receiving point reaches each control target value, The second power conditioner may be configured to perform charge / discharge control based on the output power value of the first storage battery and the predetermined control target value, while ignoring the power value at the power receiving point measured by the second wattmeter during the power outage. With this configuration, even if measurement by the second wattmeter becomes impossible during a power outage, the second power supply system can be prevented from detecting an error related to the second wattmeter.

[0015] The operating conditions include the power consumption from the first storage battery and the second storage battery during the power outage. The method may include prioritizing discharge, and during the power outage, while one of the first storage battery and the second storage battery is discharging to meet the power consumption of the load, the other battery stops charging and discharging.

[0016] During a power outage, there are many uncertain factors, such as when the power will be restored and whether or not the electric vehicle should be used as a means of transportation if the electric vehicle's storage battery is included as a power source.Therefore, the above-mentioned configuration, which avoids unnecessary operation as much as possible other than operations to cover the power consumption of the load, is preferable.

[0017] The operating conditions may include transferring power between the first storage battery and the second storage battery during the power outage, and when the dischargeable power of one of the first storage battery and the second storage battery that is the power source exceeds the power consumption of the load, charging the power source with the excess power. This type of operation is preferable when there is a need to keep the SOC of one of the storage batteries high even during a power outage.

[0018] In addition, the distributed power supply system may further include a power generation device, and may set a priority for charging the first storage battery and the second storage battery during the power outage, and may include charging one of the first storage battery and the second storage battery with the surplus generated power when there is surplus generated power obtained by subtracting the power supplied to the load from the power generated by the power generation device during the power outage, and stopping charging and discharging of the other battery.

[0019] Here, the power generation device may 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 sources, a fuel cell, etc. With such a configuration, it is possible to make maximum use of the power generated by the power generation device.

[0020] 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.

[0021] 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.

[0022] 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]

[0023] According to the present invention, a technology is provided that enables self-consumption control and prioritization of utilized power sources using a storage battery system in the event of a power outage in a power supply system including multiple distributed power sources. [Brief explanation of the drawings]

[0024] [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. [Figure 10] FIG. 10 is a schematic diagram illustrating the schematic configuration of a distributed power supply system that still has some issues. DETAILED DESCRIPTION OF THE INVENTION

[0025] <Application example> (Overall configuration of the system related to the application example) The present invention can be applied to a distributed power system 9 equipped with a plurality of storage batteries, as shown in Fig. 1, for example. The distributed power system 9 according to this application example has a load L, is interconnected with a commercial power system P, and has 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 has a switch 95 on its main circuit that switches between interconnected operation with the commercial power system P and stand-alone operation. The distributed power system 9 also has power meters 96 and 97 on its main circuit that measure the power value of the power at the receiving point.

[0026] 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.

[0027] When the first power supply system 901 is interconnected with the commercial power system P, the PCS 93 controls the charging and discharging of the storage battery 91 based on the measurement values ​​acquired by the power meter 96 and the control target values ​​related to the control commands from the control unit 90. On the other hand, during a power outage in the grid, the PCS 93 performs independent operation and performs discharge control to supply power to the load L until the SOC of the storage battery 91 reaches its lower limit. The PCS 93 is also provided with a sensor for measuring power at the power output end on the independent operation side (not shown), and acquires measurement values ​​related to the power output during independent operation. The acquired measurement values ​​are then transmitted to the PCS 94 via the control unit 90. The value measured here may be the power value itself or a voltage value.

[0028] When the first power supply system 901 is interconnected with the commercial power system P, the PCS 94 calculates the power consumption based on the measurement value acquired by the power meter 97 and the control target value related to the control command from the control unit 90. , and controls charging and discharging of the storage battery 92. Meanwhile, when the commercial power grid P experiences a power outage, the PCS 94 performs pseudo-grid-connected operation for the output of the first power supply system 901, which operates independently. Specifically, the PCS 94 uses the output voltage value of the storage battery 91, obtained from measurement values ​​acquired via the control unit 90 during the power outage, as a control index, and controls charging and discharging of the storage battery 92 toward a control target value.

[0029] According to this, the second power supply system can perform charge / discharge control based on the power at the receiving point when connected to the grid, and even during a power outage (when the first power supply system 901 is operating independently), it can perform charge / discharge control of the storage battery 92 by operating in a pseudo-grid-connected manner based on the output power of the first power supply system 901.Therefore, by linking the first power supply system 901 and the second power supply system 902, it is possible to make maximum use of the power sources possessed by both systems.

[0030] Furthermore, by basing the control commands sent by the control unit 90 to the PCS 93 and PCS 94 on operating conditions that incorporate the priority of which of the storage batteries 91 and 92 should be given priority for charging and discharging, it becomes possible to utilize each power source with a priority that meets the user's wishes, both during grid connection and during a power outage.

[0031] Specifically, by setting operating conditions that set different control target values ​​for charging and discharging between the first power supply system 901 and the second power supply system 902, and performing control based on these in each PCS93 and PCS94, it becomes possible to prioritize the charging and discharging of storage batteries between different power supply systems and operate multiple power supply systems as a whole.

[0032] <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 has 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.

[0033] 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, a 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.

[0034] 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, a switch 24 is provided on the main circuit to switch the PV storage system 29 between grid-connected operation and stand-alone operation.

[0035] (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.

[0036] The controller 100 is, for example, an information processing terminal having a gateway function as hardware, and is connected to a controller 200 of the PV power 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. The controller 100 includes a storage unit 110, a communication unit 101, and a control command generation unit 102.

[0037] 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 conjunction with each other. Each operating condition will be described in detail later.

[0038] 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.

[0039] The control command generation 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. The generated control command is transmitted to the EVPCS 10 via the communication unit 101.

[0040] (About PV storage systems) 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.

[0041] Controller 200 is, for example, an information processing terminal equipped with a gateway function as hardware, and is communicatively connected to controller 100 of V2H system 19 via communication line C. Controller 200 does not store the operating conditions in long-term memory itself, but acquires the operating conditions transmitted from controller 100 and generates control commands for hybrid PCS 20 according to the acquired operating conditions. The generated control commands are transmitted to hybrid PCS 20 via communication unit 101.

[0042] (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.

[0043] 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.

[0044] (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.

[0045] For example, when the EV battery 11 is to be discharged first, the power reception of the EVPCS 10 during discharge is The control target value of the receiving point power is set closer to reverse power flow than the control target value of the receiving point power when hybrid PCS 20 is discharging. As an example, assuming that a positive value of the receiving point power indicates 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. In other words, in this specification, "closer to reverse power flow" indicates a relative reverse power flow direction when comparing the control target values ​​of the receiving point power of each power supply system.

[0046] 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.

[0047] (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 the charging source power is (only) surplus generated power when the PV device 21 is generating power, or purchased power (such as late-night power) from the commercial power grid P is used. Here, when purchased power is used, each storage battery is charged in order with the rated input power simply based on a setting of which storage battery is to be prioritized, and charging control is stopped when the target SOC for charging is reached. For this reason, the following describes the case where charging is performed using only surplus generated power (hereinafter referred to as surplus charging).

[0048] For example, when charging EV storage battery 11 with priority, the control target value of the power receiving point when EVPCS 10 is charging is set closer to forward flow than the control target value of the power receiving point when hybrid PCS 20 is discharging. As an example, the control target value of EVPCS 10 is set to 0 W, and the control target value of hybrid PCS 20 is set to 100 W (reverse flow state). In other words, in this specification, "closer to forward flow" refers to a relatively forward flow direction when comparing the control target values ​​of the power receiving point power of each power supply system.

[0049] 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.

[0050] 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.

[0051] (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 and the PV storage battery 22 to the other, and is an operating condition for minimizing the time until the target SOC is reached. Specifically, discharge control is performed on the storage battery from which the power is interchanged, Charging control is performed on the storage battery at the transfer destination. Power transfer between storage batteries ends when the SOC of the storage battery at the transfer destination reaches the upper threshold (charging target value) or when the SOC of the storage battery from which power is being transferred reaches the lower threshold.

[0052] 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.

[0053] 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.

[0054] In this case, for example, if the target value for the discharge control of the power source is set to -100 W and the target value for the charge control of the power destination is set to -200 W, the following operation occurs. If the discharge power of the power source is greater than the sum of the load consumption and the charge power of the power destination minus the PV generation power, the power receiving point power is controlled to -100 W. If, under these conditions, the load consumption increases or the PV generation power decreases, and the power consumption side increases and exceeds the discharge power of the power source, the power receiving point power value becomes smaller than the target value for discharge control (i.e., the purchased power increases from 100 W). However, because the power destination performs charge control with a target value of -200 W, the destination reduces the charging power when the purchased power exceeds 200 W. In this way, by creating a difference between the target value for discharge control of the power source and the target value for charge control of the power destination, it is possible to seamlessly increase the charging amount during low loads and decrease the charging amount during high loads.

[0055] (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.

[0056] Furthermore, when V2H system 19 is operating autonomously, PV storage system 29 performs pseudo-grid-connected operation with respect to V2H system 19. Specifically, hybrid PCS 20 acquires information on the output power value (EV output value) from EV storage battery 11 via communication line C, and uses the acquired EV output value instead of the power at the receiving point 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, hybrid PCS 20 ignores the information on the measurement value from wattmeter 23 (by performing masking processing, for example) to prevent it from being detected as an error.

[0057] 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.

[0058] (Charging and discharging operating conditions during a power outage) Among the operating conditions related to power outages stored in the memory unit 110, the power outage discharge conditions 115 determine the priority of discharges in the event of a power outage when the power supply from the commercial power system P is interrupted. This is an operating condition in which, while one of the EV storage battery 11 and the PV storage battery 22 is discharging, charging and discharging of the other storage battery is stopped for the load power consumption that exceeds the power generation power of the PV device 21. Note that which storage battery is given priority for discharge at this time can be determined by the discharge control target value of 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).

[0059] 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).

[0060] 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.

[0061] (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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] According to the distributed power supply system 1 of this embodiment as described above, when a plurality of distributed power supply systems each having a storage battery are installed side by side, the power supply can be supplied not only during grid interconnection but also during power outages. By quasi-connecting the distributed power generation system to a power supply system that operates autonomously even in a power supply system with no power source, it is possible to efficiently operate a distributed power generation system that uses storage batteries as its power source. In addition, it is possible to control the charging and discharging of the storage batteries equipped in each power supply system in a linked manner, set priorities for charging and discharging, and share power between storage batteries, making it possible to operate each distributed power generation system in an integrated manner. Furthermore, since no special hardware configuration is required for such operation, it is possible to easily operate multiple distributed power generation systems in an integrated manner. Furthermore, when adding a new distributed power generation system to an existing system, it is possible to easily operate multiple systems in an integrated manner by changing the operating conditions stored in the controller.

[0066] <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 PSC 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.

[0067] <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. In other respects, 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.

[0068] <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 are installed side by side can also be used.

[0069] <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), a first power conditioner (10, 93), and a first wattmeter (13, 96) that measures power at a receiving point from the commercial power system; a second power supply system (29, 902) including a second storage battery (22, 92) and a second power conditioner (20, 94); a control unit (90, 100, 200) that commands the first power conditioner (10, 93) and the second power conditioner (20, 94) to perform operation control based on preset operating conditions, The operating conditions include that, when the second power conditioner (20, 94) is interconnected with the commercial power system (P), it charges and discharges the second storage battery (22, 92) based on the power at the power receiving point and a control target value, and, when the first power supply system (19, 901) performs an independent operation during a power outage in which power supply from the commercial power system (P) is cut off, it charges and discharges the second storage battery (22, 902) based on the output power from the first storage battery (11, 901) and the control target value. Distributed power systems (1, 2, 3, 9).

[0070] <Appendix 2> the first power supply system (19) and the second power supply system (29) are communicatively connected via a communication means (C); a value related to the output power from the first storage battery (11) during the stand-alone operation of the first power supply system (19) is transmitted to the second power conditioner (20) via the communication means (C); A distributed power system (1, 2, 3) as described in Appendix 1.

[0071] <Appendix 3> the second power supply system (29) has a second wattmeter (23) that measures power at the power receiving point; When interconnected with 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 power at the power receiving point reaches respective control target values, During the power outage, the second power conditioner (20) performs charge / discharge control based on the output power value of the first storage battery (11) and the predetermined control target value, while ignoring the value of the power at the power receiving point measured by the second wattmeter (23). A distributed power system (1, 2, 3) according to appendix 1 or 2.

[0072] <Appendix 4> The operating conditions determine a priority order for discharging from the first storage battery (11) and the second storage battery (22) during the power outage, and include a condition in which, during the power outage, while one of the first storage battery (11) and the second storage battery (22) is discharging to satisfy the power consumption of the load, the other is stopping charging or discharging. A distributed power system (1, 2, 3) according to any one of appendices 1 to 3.

[0073] <Appendix 5> The operating conditions include: during the power outage, electric power is exchanged between the first storage battery (11) and the second storage battery (22); and when the dischargeable power of one of the first storage battery (11) and the second storage battery (22), which is the source of the electric power exchange, exceeds the power consumption of the load (L), the excess power is used to charge the destination of the electric power exchange. A distributed power system (1, 2, 3) according to any one of appendices 1 to 4.

[0074] <Appendix 6> Further comprising a power generation device (21). A distributed power system (1, 2, 3) according to any one of appendices 1 to 5.

[0075] <Appendix 7> The operating conditions determine a priority order for charging the first storage battery (11) and the second storage battery (22) during the power outage, and include: when surplus generated power is generated by subtracting power supplied to the load (L) from power generated by the power generation device (21) during the power outage, charging the surplus generated power into one of the first storage battery (11) and the second storage battery (22) and stopping charging / discharging of the other storage battery. A distributed power system (1, 2, 3) as described in Appendix 6.

[0076] <Appendix 8> 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 6 or 7.

[0077] <Appendix 9> 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 8.

[0078] <Appendix 10> Further comprising an input unit (300) that accepts input operations related to the setting of the operating conditions. A distributed power system (1, 2, 3) according to any one of appendices 1 to 9. [Explanation of symbols]

[0079] 1, 2, 3, 8, 9... Distributed Power Systems 10···EVPCS 11. EV battery 12···V2H Stand 13, 23, 26, 87, 88... Wattmeter 14, 24, 85, 95...Switcher 19. V2H system 20 Hybrid PCS 21...PV equipment 22. PV battery 100, 200 controller 300···Information processing terminal 90 Control unit 81, 82, 91, 92... Storage battery 83, 84, 93, 94... PCS 801, 901... First power supply system 802, 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, a first power conditioner, and a first wattmeter that measures power at a receiving point from the commercial power system; a second power supply system including a second storage battery and a second power conditioner; a control unit that commands operation control based on preset operating conditions to the first power conditioner and the second power conditioner, The operating conditions include that, when the second power conditioner is interconnected with the commercial power system, the second power conditioner charges and discharges the second storage battery based on the power at the power receiving point and a control target value, and when the first power supply system performs independent operation during a power outage in which power supply from the commercial power system is cut off, the second power conditioner charges and discharges the second storage battery based on the output power from the first storage battery and the control target value. Distributed power systems.

2. the first power supply system and the second power supply system are communicatively connected via a communication means; a value related to the output power from the first storage battery during the independent operation of the first power supply system is transmitted to the second power conditioner via the communication means; The distributed power system of claim 1 .

3. the second power supply system has a second power meter that measures power at the power receiving point; When interconnected with 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 at the power receiving point becomes the respective control target value, The second power conditioner, during the power outage, ignores the value of the power at the power receiving point measured by the second wattmeter and performs charge / discharge control based on the output power of the first storage battery and the control target value. The distributed power system of claim 1 .

4. The operating conditions include determining a priority order for discharging from the first storage battery and the second storage battery during the power outage, and including stopping charging and discharging of one of the first storage battery and the second storage battery while the other is discharging to satisfy the power consumption of the load during the power outage. The distributed power system of claim 1 .

5. The operating conditions include: transferring power between the first storage battery and the second storage battery during the power outage; and when the dischargeable power of one of the first storage battery and the second storage battery that is the power transfer source exceeds the power consumption of the load, charging the power transfer destination with the excess power. The distributed power system of claim 1 .

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

7. The operating conditions determine a priority order for charging the first storage battery and the second storage battery during the power outage, and include charging one of the first storage battery and the second storage battery with the surplus generated power when surplus generated power is generated by subtracting the power supplied to the load from the power generated by the power generation device during the power outage, and stopping charging and discharging the other storage battery. The distributed power system of claim 6.

8. 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 6.

9. 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 .

10. 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 9.

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