WO2024116492A1 - Power conversion system - Google Patents

Power conversion system Download PDF

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Publication number
WO2024116492A1
WO2024116492A1 PCT/JP2023/030483 JP2023030483W WO2024116492A1 WO 2024116492 A1 WO2024116492 A1 WO 2024116492A1 JP 2023030483 W JP2023030483 W JP 2023030483W WO 2024116492 A1 WO2024116492 A1 WO 2024116492A1
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WO
WIPO (PCT)
Prior art keywords
power
converter
bus
storage battery
stationary
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PCT/JP2023/030483
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French (fr)
Japanese (ja)
Inventor
拓也 狩川
良典 則竹
友美 加藤
Original Assignee
パナソニックＩｐマネジメント株式会社
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Publication of WO2024116492A1 publication Critical patent/WO2024116492A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/50—Charging stations characterised by energy-storage or power-generation means
    • B60L53/53—Batteries
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L53/00—Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
    • B60L53/60—Monitoring or controlling charging stations
    • B60L53/62—Monitoring or controlling charging stations in response to charging parameters, e.g. current, voltage or electrical charge
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
    • H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells

Definitions

  • This disclosure relates to a power conversion system to which multiple power storage units are connected.
  • This disclosure has been made in light of these circumstances, and its purpose is to provide technology that improves the convenience of a power conversion system to which multiple power storage units are connected.
  • a power conversion system includes a first DC/DC converter that charges and discharges a first power storage unit, a second DC/DC converter that charges and discharges a second power storage unit, a DC bus to which the first DC/DC converter and the second DC/DC converter are connected in parallel, and an inverter connected to the DC bus. While the inverter is outputting AC power, power can be transferred from the first power storage unit to the second power storage unit.
  • This disclosure makes it possible to improve the convenience of a power conversion system to which multiple power storage units are connected.
  • FIG. 11 is a diagram for explaining a second configuration example of a power conversion system according to an embodiment.
  • This figure shows an example of transitions in bus voltage, inverter independent output, output of a stationary DC/DC converter, and output of an on-board DC/DC converter when power is transferred from a stationary storage battery to an on-board storage battery during independent operation.
  • This figure shows an example of transitions in bus voltage, inverter independent output, output of a stationary DC/DC converter, and output of an on-board DC/DC converter when power is transferred from an on-board storage battery to a stationary storage battery during independent operation.
  • FIG. 11 is a diagram showing an example in which the bus voltage-output power characteristic of a converter is defined by a linear function.
  • FIG. 1 is a diagram for explaining a configuration example 1 of a power conversion system 1 according to an embodiment.
  • the power conversion system 1 includes a DC/DC converter 11, an inverter 12, a converter control circuit 13, an inverter control circuit 14, a control unit 15, a grid-connection relay RY1, an independent output relay RY2, a stationary DC/DC converter 21, a stationary converter control circuit 22, an on-board DC/DC converter 31, and an on-board converter control circuit 32.
  • the DC/DC converter 11, inverter 12, converter control circuit 13, inverter control circuit 14, control unit 15, grid-connection relay RY1, and independent output relay RY2 are, for example, configured as a power conditioner for a solar power generation system.
  • the stationary DC/DC converter 21 and stationary converter control circuit 22 are, for example, configured as a charge/discharge converter for the stationary storage battery 7.
  • the stationary DC/DC converter 21 and stationary converter control circuit 22 may be built into the power conditioner.
  • the vehicle-mounted DC/DC converter 31 and vehicle-mounted converter control circuit 32 are, for example, configured as a V2H converter.
  • the vehicle-mounted DC/DC converter 31 and vehicle-mounted converter control circuit 32 may be built into the power conditioner.
  • the solar cell 6 is a power generation device that utilizes the photovoltaic effect to directly convert light energy into DC power.
  • a silicon solar cell a solar cell made of a material such as a compound semiconductor, a dye-sensitized solar cell, an organic thin-film solar cell, etc. can be used.
  • the solar cell 6 is connected to a DC/DC converter 11, and outputs the generated power to the power conversion system 1.
  • the DC/DC converter 11 is a converter that can adjust the voltage of the DC power output from the solar cell 6.
  • the DC/DC converter 11 can be configured, for example, as a step-up chopper.
  • the converter control circuit 13 controls the DC/DC converter 11.
  • the converter control circuit 13 controls the DC/DC converter 11 using MPPT (Maximum Power Point Tracking) so that the output power of the solar cell 6 is maximized.
  • MPPT Maximum Power Point Tracking
  • the converter control circuit 13 measures the input voltage and input current of the DC/DC converter 11, which are the output voltage and output current of the solar cell 6, to estimate the power generated by the solar cell 6.
  • the converter control circuit 13 generates a voltage command value for making the power generated by the solar cell 6 the maximum power point (optimum operating point) based on the measured output voltage of the solar cell 6 and the estimated power generation.
  • the converter control circuit 13 searches for the maximum power point by changing the operating point voltage by a predetermined step width according to the hill climbing method, and generates a voltage command value to maintain the maximum power point.
  • the DC/DC converter 11 performs switching operation in response to a drive signal based on the generated voltage command value.
  • the inverter 12 is a bidirectional DC/AC converter connected between the DC bus Bd and the distribution board 3. More specifically, the AC side output path of the inverter 12 branches into a grid-connected output path and an independent output path.
  • the grid-connected output path of the inverter 12 is connected to the distribution board 3 via a grid-connected relay RY1.
  • a commercial power system hereinafter simply referred to as system 2) and general loads 4 are connected to the distribution board 3.
  • the general loads 4 are a general term for loads installed within the home.
  • the independent output path of the inverter 12 is connected to the specific load 5 via the independent output relay RY2.
  • the specific load 5 is a general term for loads (e.g., lighting fixtures, refrigerators, etc.) to which a power supply needs to be ensured even during a power outage.
  • An AC outlet may be installed on the independent output path. Note that in the case of a configuration in which the entire general load 4 is backed up during a power outage, there is no need to branch off the independent output path from the AC output path of the inverter 12.
  • a DC/DC converter 11 for the solar cell 6, a stationary DC/DC converter 21, and an on-board DC/DC converter 31 are connected in parallel to the DC bus Bd.
  • the inverter 12 converts the DC power supplied from the DC bus Bd into AC power, and outputs the converted AC power to the distribution board 3 or the specific load 5.
  • the inverter 12 can also convert the AC power supplied from the system 2 via the distribution board 3 and the interconnection relay RY1 into DC power, and output the converted DC power to the DC bus Bd.
  • the inverter control circuit 14 controls the inverter 12. As a basic control during system interconnection, the inverter control circuit 14 controls the inverter 12 so that the voltage of the DC bus Bd maintains a target value. Specifically, the inverter control circuit 14 detects the voltage of the DC bus Bd and generates a current command value for matching the detected bus voltage to the target value. If the voltage of the DC bus Bd is higher than the target value, the inverter control circuit 14 generates a current command value for increasing the output power of the inverter 12, and if the voltage of the DC bus Bd is lower than the target value, the inverter control circuit 14 generates a current command value for decreasing the output power of the inverter 12. The inverter 12 performs switching operation in response to a drive signal based on the generated current command value.
  • the control unit 15 provides overall control of the entire power conversion system 1.
  • the control unit 15, inverter control circuit 14, and converter control circuits 13, 22, and 32 can be realized by a combination of hardware and software resources, or by hardware resources alone.
  • Hardware resources that can be used include analog circuits, logic circuits, microcontrollers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs.
  • Software resources that can be used include programs such as firmware.
  • the control unit 15 controls the grid-connected relay RY1 to be on (closed) and the independent output relay RY2 to be off (open).
  • the control unit 15 controls the grid-connected relay RY1 to be off and the independent output relay RY2 to be on.
  • the control unit 15 can detect a power outage in the grid 2 based on the measured voltage on the AC side of the inverter 12. When the control unit 15 detects a power outage, it switches from the grid-connected mode to the independent operation mode. In the independent operation mode, the control unit 15 controls the inverter control circuit 14 to cause the inverter 12 to output an AC voltage corresponding to the grid frequency and grid voltage.
  • the remote controller 16 displays the status of the power conversion system 1, accepts operations from the user, and transmits operation signals based on the accepted operations to the control unit 15.
  • the stationary storage battery 7 is capable of charging and discharging power, and includes a storage battery such as a lithium ion storage battery, a nickel metal hydride storage battery, or a lead storage battery. Note that instead of a storage battery, a supercapacitor such as an electric double layer capacitor or a lithium ion capacitor may also be included.
  • a storage battery such as a lithium ion storage battery, a nickel metal hydride storage battery, or a lead storage battery.
  • a supercapacitor such as an electric double layer capacitor or a lithium ion capacitor may also be included.
  • the stationary storage battery 7 is connected to a stationary DC/DC converter 21, and charging and discharging are controlled by the stationary DC/DC converter 21.
  • the stationary DC/DC converter 21 is connected between the stationary storage battery 7 and the DC bus Bd, and is a bidirectional DC/DC converter for charging and discharging the stationary storage battery 7.
  • the stationary converter control circuit 22 controls the stationary DC/DC converter 21.
  • the stationary converter control circuit 22 controls the charging and discharging of the stationary DC/DC converter 21 based on command values transmitted from the control unit 15 via a communication line.
  • constant current (CC) control and constant voltage (CV) control are possible as charge and discharge control.
  • the stationary converter control circuit 22 also monitors the voltage of the DC bus Bd, and can control the stationary DC/DC converter 21 to adaptively change the current command value according to the bus voltage.
  • the on-board storage battery 8 is a drive storage battery mounted on the electric vehicle, and may be a lithium-ion storage battery, a nickel-metal hydride storage battery, or the like.
  • the electric vehicle and the power conversion system 1 are connected by a charging cable.
  • the on-board storage battery 8 is connected to an on-board DC/DC converter 31 when the electric vehicle is parked at home, and charging and discharging are controlled by the on-board DC/DC converter 31.
  • the on-board DC/DC converter 31 is a bidirectional DC/DC converter that is connected between the on-board storage battery 30 and the DC bus Bd, and charges and discharges the on-board storage battery 30 when the electric vehicle is parked at home.
  • the on-board converter control circuit 32 controls the on-board DC/DC converter 31.
  • the on-board converter control circuit 32 controls the charging and discharging of the on-board DC/DC converter 31 based on a command value sent from the control unit 15 via a communication line, or a command value sent from the electric vehicle via a communication line in the charging cable.
  • charge and discharge control for example, constant current (CC) control and constant voltage (CV) control are possible.
  • the on-board converter control circuit 32 can also monitor the voltage of the DC bus Bd, and adaptively change the current command value of the on-board DC/DC converter 31 according to the bus voltage.
  • FIG. 2 is a diagram for explaining a configuration example 2 of a power conversion system 1 according to an embodiment.
  • a solar cell 6 is not installed, and the power conversion system 1 does not include a DC/DC converter 11 and a converter control circuit 13.
  • the other configurations are the same as those of the configuration example 1 shown in FIG. 1.
  • control unit 15 when the control unit 15 detects a power outage in the system 2, it sends an independent operation command to the inverter control circuit 14.
  • power can be transferred from the stationary storage battery 7 to the vehicle storage battery 8, or from the vehicle storage battery 8 to the stationary storage battery 7.
  • the user specifies the source storage battery and the destination storage battery from the remote controller 16.
  • the control unit 15 sends a discharge command to the source converter control circuit and a charge command to the destination converter control circuit.
  • the stationary converter control circuit 22 controls the output power from the stationary DC/DC converter 21 to the DC bus Bd (the input power from the DC bus Bd to the stationary DC/DC converter 21) so as not to exceed the rated power of the stationary storage battery 7 and not to deviate from the range of the set upper and lower voltage limits of the DC bus Bd.
  • the output power from the stationary DC/DC converter 21 to the DC bus Bd is basically positive (discharging).
  • the output power from the stationary DC/DC converter 21 to the DC bus Bd is basically negative (charging). Note that if the power consumption of the specific load 5 increases, the output power from the stationary DC/DC converter 21 to the DC bus Bd may be controlled to be positive (discharging) even if the stationary storage battery 7 is designated as the transfer destination. Also, in configuration example 1, if the power generation power of the solar cell 6 increases, the output power from the stationary DC/DC converter 21 to the DC bus Bd may be controlled to be negative (charging) even if the stationary storage battery 7 is designated as the transfer source.
  • the vehicle-mounted converter control circuit 32 controls the output power from the vehicle-mounted DC/DC converter 31 to the DC bus Bd (the input power from the DC bus Bd to the vehicle-mounted DC/DC converter 31) so as not to exceed the rated power of the vehicle-mounted storage battery 8 and not to deviate from the range of the set upper and lower limit voltages of the DC bus Bd.
  • the output power from the on-board DC/DC converter 31 to the DC bus Bd is basically positive (discharging), and when the on-board storage battery 8 is designated as the transfer destination, the output power from the on-board DC/DC converter 31 to the DC bus Bd is basically negative (charging). Note that if the power consumption of the specific load 5 increases, the output power from the on-board DC/DC converter 31 to the DC bus Bd may be controlled to be positive (discharging) even if the on-board storage battery 8 is designated as the transfer destination.
  • the output power from the on-board DC/DC converter 31 to the DC bus Bd may be controlled to be negative (charging) even if the on-board storage battery 8 is designated as the transfer source.
  • Figure 3 shows an example of transitions in bus voltage, the independent output of inverter 12, the output of stationary DC/DC converter 21, and the output of on-board DC/DC converter 31 when power is transferred from stationary storage battery 7 to on-board storage battery 8 during independent operation.
  • solar cell 6 it is assumed that solar cell 6 is not connected, the independent output of inverter 12 (power consumption of specific load 5) is 1 kW, the rated power of stationary storage battery 7 is ⁇ 3 kW, and the rated power of on-board storage battery 8 is ⁇ 6 kW.
  • control unit 15 When the control unit 15 detects a power outage in system 2, it turns off the interconnection relay RY1 and starts preparation for independent operation. During the preparation period for independent operation, the voltage of the DC bus Bd is maintained at 360V by the output voltage of the stationary storage battery 7 or the vehicle-mounted storage battery 8. The control unit 15 turns on the independent output relay RY2 to start independent operation.
  • the stationary DC/DC converter 21 starts discharging from the stationary storage battery 7 to the DC bus Bd.
  • vehicle-mounted DC/DC converter 31 starts charging from the DC bus Bd to the vehicle-mounted storage battery 8.
  • the stationary converter control circuit 22 maintains the output power of the stationary DC/DC converter 21 at the rated power of the stationary storage battery 7.
  • the in-vehicle converter control circuit 32 When the voltage of the DC bus Bd reaches the set lower limit voltage, the in-vehicle converter control circuit 32 reduces the amount of charge to the in-vehicle storage battery 8 so that the voltage of the DC bus Bd does not fall below the set lower limit voltage. If the voltage drop of the DC bus Bd does not stop even when the amount of charge is reduced to 0 W, the in-vehicle converter control circuit 32 switches from charging to discharging.
  • Figure 4 shows an example of the transition of the bus voltage, the independent output of the inverter 12, the output of the stationary DC/DC converter 21, and the output of the vehicle-mounted DC/DC converter 31 when power is transferred from the vehicle-mounted storage battery 8 to the stationary storage battery 7 during independent operation.
  • the prerequisites are the same as those in the example of Figure 3.
  • control unit 15 When the control unit 15 detects a power outage in system 2, it turns off the interconnection relay RY1 and starts preparation for independent operation. During the preparation period for independent operation, the voltage of the DC bus Bd is maintained at 360V by the output voltage of the stationary storage battery 7 or the vehicle-mounted storage battery 8. The control unit 15 turns on the independent output relay RY2 to start independent operation.
  • the stationary DC/DC converter 21 starts charging the stationary storage battery 7 from the DC bus Bd.
  • vehicle-mounted DC/DC converter 31 starts discharging from the vehicle-mounted storage battery 8 to the DC bus Bd.
  • the stationary converter control circuit 22 maintains the input power of the stationary DC/DC converter 21 at the rated power of the stationary storage battery 7.
  • the vehicle converter control circuit 32 reduces the amount of discharge from the vehicle storage battery 8 so that the voltage of the DC bus Bd does not exceed the set upper limit voltage.
  • the maximum value of the output power of the stationary DC/DC converter 21 is limited to the rated power of the stationary storage battery 7
  • the maximum value of the output power of the vehicle-mounted DC/DC converter 31 is limited to the rated power of the vehicle-mounted storage battery 8.
  • the user may specify the maximum power value when power is exchanged between the stationary storage battery 7 and the vehicle-mounted storage battery 8 during independent operation of the inverter 12.
  • the maximum values of the output power of the stationary DC/DC converter 21 and the output power of the vehicle-mounted DC/DC converter 31 are limited to the maximum power value specified by the user.
  • urgency is low
  • power can be transferred at a low rate to prioritize suppression of deterioration of the storage batteries.
  • the output power of the stationary DC/DC converter 21 does not exceed the rated power of the stationary storage battery 7, and the output power of the vehicle-mounted DC/DC converter 31 does not exceed the rated power of the vehicle-mounted storage battery 8, it is necessary to determine which converter, the stationary DC/DC converter 21 or the vehicle-mounted DC/DC converter 31, will control the bus voltage.
  • a bus voltage-output power characteristic with a predetermined slope, it is possible to determine one converter to control the bus voltage.
  • Figure 5 shows an example in which the converter bus voltage-output power characteristics are defined by a linear function.
  • the stationary converter control circuit 22 sets the set upper limit voltage and set lower limit voltage of the stationary DC/DC converter 21 lower as the output power of the stationary DC/DC converter 21 is higher.
  • the vehicle converter control circuit 32 sets the set upper limit voltage and set lower limit voltage of the vehicle DC/DC converter 31 lower as the output power of the vehicle DC/DC converter 31 is higher.
  • the bus voltage is controlled by the charging side DC/DC converter when the bus voltage reaches the set upper limit voltage, and by the discharging side DC/DC converter when the bus voltage reaches the set lower limit voltage.
  • the stationary converter control circuit 22 measures the power of the DC bus Bd and adaptively controls the charge/discharge amount (current command value) of the stationary DC/DC converter 21, or that the vehicle-mounted converter control circuit 32 measures the power of the DC bus Bd and adaptively controls the charge/discharge amount (current command value) of the vehicle-mounted DC/DC converter 31.
  • the inverter control circuit 14 to measure the power of the DC bus Bd, and the control unit 15 to adaptively determine the charge/discharge amount (current command value) of the stationary DC/DC converter 21 or the charge/discharge amount (current command value) of the vehicle-mounted DC/DC converter 31, and to transmit the charge/discharge amount (current command value) to the stationary converter control circuit 22 or the vehicle-mounted converter control circuit 32 via high-speed communication.
  • the stationary storage battery 7 by enabling power transfer between multiple storage batteries connected to the power conversion system 1 during independent operation of the inverter 12, it is possible to improve user convenience. For example, during a power outage, it is possible to charge the stationary storage battery 7 with power from the vehicle-mounted storage battery 8 charged at another location while the system is operating independently. In addition, it is possible to charge the stationary storage battery 7 with power generated by the solar cell 6 while the system is operating independently.
  • control of transferring power between multiple storage batteries during independent operation of the inverter 12 has been described.
  • control of transferring power between the above-mentioned multiple storage batteries may also be implemented during a reverse power flow period during grid-connected operation.
  • the transfer of power between the stationary storage battery 7 and the vehicle-mounted storage battery 8 has been described, but the present disclosure is also applicable to the transfer of power between stationary storage batteries.
  • the present disclosure is also applicable to the transfer of power between stationary storage batteries.
  • the storage deterioration of the storage batteries can be reduced by transferring power to the storage battery with the lower temperature.
  • the power conversion system (1) is capable of transferring power from the first power storage unit (7) to the second power storage unit (8) while the inverter (12) is outputting AC power. This can improve user convenience.
  • the power conversion system (1) according to item 1 or 2. This enables power transfer between the power storage units while stabilizing the voltage of the DC bus (Bd). [Item 5] the higher the output power of the first DC/DC converter (21), the lower the upper limit voltage and the lower limit voltage of the first DC/DC converter (21) are set, The higher the output power of the second DC/DC converter (31), the lower the upper limit voltage and the lower limit voltage of the second DC/DC converter (31) are set. 5.
  • This disclosure can be used in a system in which an on-board storage battery and a stationary storage battery are connected in parallel.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)

Abstract

A first DC/DC converter (21) charges and discharges a first power storage unit (7). A second DC/DC converter (31) charges and discharges a second power storage unit (8). The first DC/DC converter (21) and the second DC/DC converter (31) are connected in parallel to a DC bus (Bd). An inverter (12) is connected to the DC bus (Bd). Electric power can be transferred from the first power storage unit (7) to the second power storage unit (8) while the inverter (12) outputs AC power.

Description

電力変換システムPower Conversion Systems
　本開示は、複数の蓄電部が接続された電力変換システムに関する。 This disclosure relates to a power conversion system to which multiple power storage units are connected.
　近年、蓄電システム、太陽光発電システムと蓄電システムを連携させたハイブリッド蓄電システム（創蓄連携システムとも称される）が普及してきている。また、電気自動車（ＥＶ）、プラグインハイブリッド車（ＰＨＶ）などの電動車の普及に伴い、Ｖ２Ｈ（Vehicle to Home）コンバータを介して電動車と、蓄電システムまたはハイブリッド蓄電システムを連携させる使用形態（例えば、特許文献１参照）が拡大している。 In recent years, power storage systems and hybrid power storage systems (also called linked energy generation and storage systems) that link solar power generation systems with power storage systems have become popular. In addition, with the spread of electric vehicles such as electric vehicles (EVs) and plug-in hybrid vehicles (PHVs), there has been an expansion in the use of electric vehicles that link power storage systems or hybrid power storage systems via V2H (Vehicle to Home) converters (see, for example, Patent Document 1).
　このような状況下、蓄電システムまたはハイブリッド蓄電システムを構成する電力変換システムに、複数の蓄電池が接続されるケースが増えてきている。従来、複数の蓄電池が接続された電力変換システムが自立運転する際は、全ての蓄電池コンバータが同じ放電方向に電力変換することでシステム動作を成立させていた。例えば、太陽電池が接続されていない蓄電システムでは、自立負荷の消費電力を賄うため全ての蓄電池コンバータが放電動作をしていた。また、太陽電池が接続されたハイブリッド蓄電システムでは、自立負荷の消費電力を太陽電池の発電電力が上回った場合、その余剰電力を充電するために全ての蓄電池コンバータが充電動作をしていた。電力変換システムに接続された全ての蓄電池が定置用蓄電池である場合、上記制御で基本的に、ユーザが不便を感じることは少なかった。 In these circumstances, there are an increasing number of cases where multiple storage batteries are connected to a power conversion system that constitutes a storage system or hybrid storage system. Conventionally, when a power conversion system connected to multiple storage batteries operates independently, the system operation is established by all storage battery converters converting power in the same discharging direction. For example, in a storage system that does not have solar cells connected, all storage battery converters perform discharging operation to cover the power consumption of the independent load. Also, in a hybrid storage system connected to solar cells, when the power generated by the solar cells exceeds the power consumption of the independent load, all storage battery converters perform charging operation to charge the surplus power. When all storage batteries connected to the power conversion system are stationary storage batteries, the above control generally causes little inconvenience to users.
特開２０２２－９７７２８号公報JP 2022-97728 A
　しかしながら、性質の異なる複数の蓄電池が組み合わせられる場合、例えば車載蓄電池と定置用蓄電池が組み合わせられる場合、上記制御では両者の蓄電池コンバータの電力方向が同一であるため、車載蓄電池と定置用蓄電池間で電力を融通することができなかった。例えば、停電時において、他の場所で電動車に搭載された蓄電池に充電した電力を自立運転しながら家庭用蓄電池に充電したいというニーズや、太陽電池の発電電力で充電した家庭用蓄電池の電力を自立運転しながら車載蓄電池に充電したいというニーズがある。 However, when multiple storage batteries with different properties are combined, for example when an on-board storage battery and a stationary storage battery are combined, the power direction of the storage battery converters for both is the same in the above control, so it is not possible to interchange power between the on-board storage battery and the stationary storage battery. For example, during a power outage, there is a need to be able to charge a home storage battery while the vehicle is operating autonomously using power stored in a storage battery installed in an electric vehicle at another location, or to charge a home storage battery that has been charged with power generated by a solar cell and then used to charge the on-board storage battery while the vehicle is operating autonomously.
　本開示はこうした状況に鑑みなされたものであり、その目的は、複数の蓄電部が接続された電力変換システムの利便性を向上させる技術を提供することにある。 This disclosure has been made in light of these circumstances, and its purpose is to provide technology that improves the convenience of a power conversion system to which multiple power storage units are connected.
　上記課題を解決するために、本開示のある態様の電力変換システムは、第１蓄電部を充放電する第１ＤＣ／ＤＣコンバータと、第２蓄電部を充放電する第２ＤＣ／ＤＣコンバータと、前記第１ＤＣ／ＤＣコンバータおよび前記第２ＤＣ／ＤＣコンバータが並列に接続される直流バスと、前記直流バスに接続されるインバータと、を備える。前記インバータが交流電力を出力中に、前記第１蓄電部から前記第２蓄電部へ電力移動が可能である。 In order to solve the above problem, a power conversion system according to one embodiment of the present disclosure includes a first DC/DC converter that charges and discharges a first power storage unit, a second DC/DC converter that charges and discharges a second power storage unit, a DC bus to which the first DC/DC converter and the second DC/DC converter are connected in parallel, and an inverter connected to the DC bus. While the inverter is outputting AC power, power can be transferred from the first power storage unit to the second power storage unit.
　本開示によれば、複数の蓄電部が接続された電力変換システムの利便性を向上させることができる。 This disclosure makes it possible to improve the convenience of a power conversion system to which multiple power storage units are connected.
実施の形態に係る電力変換システムの構成例１を説明するための図である。1 is a diagram for explaining a first example of a configuration of a power conversion system according to an embodiment; 実施の形態に係る電力変換システムの構成例２を説明するための図である。FIG. 11 is a diagram for explaining a second configuration example of a power conversion system according to an embodiment. 自立運転中に、定置用蓄電池から車載蓄電池へ電力融通する場合の、バス電圧、インバータの自立出力、定置用ＤＣ／ＤＣコンバータの出力および車載用ＤＣ／ＤＣコンバータの出力の遷移の一例を示す図である。This figure shows an example of transitions in bus voltage, inverter independent output, output of a stationary DC/DC converter, and output of an on-board DC/DC converter when power is transferred from a stationary storage battery to an on-board storage battery during independent operation. 自立運転中に、車載蓄電池から定置用蓄電池へ電力融通する場合の、バス電圧、インバータの自立出力、定置用ＤＣ／ＤＣコンバータの出力および車載用ＤＣ／ＤＣコンバータの出力の遷移の一例を示す図である。This figure shows an example of transitions in bus voltage, inverter independent output, output of a stationary DC/DC converter, and output of an on-board DC/DC converter when power is transferred from an on-board storage battery to a stationary storage battery during independent operation. コンバータのバス電圧－出力電力特性を一次関数で規定した例を示す図である。FIG. 11 is a diagram showing an example in which the bus voltage-output power characteristic of a converter is defined by a linear function.
　図１は、実施の形態に係る電力変換システム１の構成例１を説明するための図である。電力変換システム１は、ＤＣ／ＤＣコンバータ１１、インバータ１２、コンバータ制御回路１３、インバータ制御回路１４、制御部１５、連系リレーＲＹ１、自立出力リレーＲＹ２、定置用ＤＣ／ＤＣコンバータ２１、定置用コンバータ制御回路２２、車載用ＤＣ／ＤＣコンバータ３１および車載用コンバータ制御回路３２を含む。 FIG. 1 is a diagram for explaining a configuration example 1 of a power conversion system 1 according to an embodiment. The power conversion system 1 includes a DC/DC converter 11, an inverter 12, a converter control circuit 13, an inverter control circuit 14, a control unit 15, a grid-connection relay RY1, an independent output relay RY2, a stationary DC/DC converter 21, a stationary converter control circuit 22, an on-board DC/DC converter 31, and an on-board converter control circuit 32.
　ＤＣ／ＤＣコンバータ１１、インバータ１２、コンバータ制御回路１３、インバータ制御回路１４、制御部１５、連系リレーＲＹ１および自立出力リレーＲＹ２は、例えば、太陽光発電システム用のパワーコンディショナで構成される。定置用ＤＣ／ＤＣコンバータ２１および定置用コンバータ制御回路２２は、例えば、定置用蓄電池７用の充放電コンバータで構成される。なお、定置用ＤＣ／ＤＣコンバータ２１および定置用コンバータ制御回路２２は上記パワーコンディショナ内に内蔵されてもよい。車載用ＤＣ／ＤＣコンバータ３１および車載用コンバータ制御回路３２は、例えば、Ｖ２Ｈコンバータで構成される。なお、車載用ＤＣ／ＤＣコンバータ３１および車載用コンバータ制御回路３２は上記パワーコンディショナ内に内蔵されてもよい。 The DC/DC converter 11, inverter 12, converter control circuit 13, inverter control circuit 14, control unit 15, grid-connection relay RY1, and independent output relay RY2 are, for example, configured as a power conditioner for a solar power generation system. The stationary DC/DC converter 21 and stationary converter control circuit 22 are, for example, configured as a charge/discharge converter for the stationary storage battery 7. The stationary DC/DC converter 21 and stationary converter control circuit 22 may be built into the power conditioner. The vehicle-mounted DC/DC converter 31 and vehicle-mounted converter control circuit 32 are, for example, configured as a V2H converter. The vehicle-mounted DC/DC converter 31 and vehicle-mounted converter control circuit 32 may be built into the power conditioner.
　太陽電池６は光起電力効果を利用し、光エネルギーを直接、直流電力に変換する発電装置である。太陽電池６として、シリコン太陽電池、化合物半導体などを素材にした太陽電池、色素増感太陽電池、有機薄膜太陽電池などが使用される。太陽電池６は、ＤＣ／ＤＣコンバータ１１と接続され、発電した電力を電力変換システム１に出力する。ＤＣ／ＤＣコンバータ１１は、太陽電池６から出力される直流電力の電圧を調整可能なコンバータである。ＤＣ／ＤＣコンバータ１１は例えば、昇圧チョッパで構成することができる。 The solar cell 6 is a power generation device that utilizes the photovoltaic effect to directly convert light energy into DC power. As the solar cell 6, a silicon solar cell, a solar cell made of a material such as a compound semiconductor, a dye-sensitized solar cell, an organic thin-film solar cell, etc. can be used. The solar cell 6 is connected to a DC/DC converter 11, and outputs the generated power to the power conversion system 1. The DC/DC converter 11 is a converter that can adjust the voltage of the DC power output from the solar cell 6. The DC/DC converter 11 can be configured, for example, as a step-up chopper.
　コンバータ制御回路１３はＤＣ／ＤＣコンバータ１１を制御する。コンバータ制御回路１３は、太陽電池６の出力電力が最大になるようＤＣ／ＤＣコンバータ１１をＭＰＰＴ(Maximum Power Point Tracking) 制御する。具体的にはコンバータ制御回路１３は、太陽電池６の出力電圧および出力電流である、ＤＣ／ＤＣコンバータ１１の入力電圧および入力電流を測定して太陽電池６の発電電力を推定する。コンバータ制御回路１３は、測定した太陽電池６の出力電圧と推定した発電電力をもとに、太陽電池６の発電電力を最大電力点（最適動作点）にするための電圧指令値を生成する。コンバータ制御回路１３は例えば、山登り法にしたがい動作点電圧を所定のステップ幅で変化させて最大電力点を探索し、最大電力点を維持するように電圧指令値を生成する。ＤＣ／ＤＣコンバータ１１は、生成された電圧指令値に基づく駆動信号に応じてスイッチング動作する。 The converter control circuit 13 controls the DC/DC converter 11. The converter control circuit 13 controls the DC/DC converter 11 using MPPT (Maximum Power Point Tracking) so that the output power of the solar cell 6 is maximized. Specifically, the converter control circuit 13 measures the input voltage and input current of the DC/DC converter 11, which are the output voltage and output current of the solar cell 6, to estimate the power generated by the solar cell 6. The converter control circuit 13 generates a voltage command value for making the power generated by the solar cell 6 the maximum power point (optimum operating point) based on the measured output voltage of the solar cell 6 and the estimated power generation. For example, the converter control circuit 13 searches for the maximum power point by changing the operating point voltage by a predetermined step width according to the hill climbing method, and generates a voltage command value to maintain the maximum power point. The DC/DC converter 11 performs switching operation in response to a drive signal based on the generated voltage command value.
　インバータ１２は、直流バスＢｄと分電盤３との間に接続される双方向ＤＣ／ＡＣコンバータである。より具体的には、インバータ１２の交流側の出力経路は、連系出力経路と自立出力経路に分岐される。インバータ１２の連系出力経路は、連系リレーＲＹ１を介して分電盤３に接続される。分電盤３には、商用電力系統（以下、単に系統２という）と一般負荷４が接続される。一般負荷４は宅内に設置された負荷の総称である。 The inverter 12 is a bidirectional DC/AC converter connected between the DC bus Bd and the distribution board 3. More specifically, the AC side output path of the inverter 12 branches into a grid-connected output path and an independent output path. The grid-connected output path of the inverter 12 is connected to the distribution board 3 via a grid-connected relay RY1. A commercial power system (hereinafter simply referred to as system 2) and general loads 4 are connected to the distribution board 3. The general loads 4 are a general term for loads installed within the home.
　インバータ１２の自立出力経路は、自立出力リレーＲＹ２を介して特定負荷５に接続される。特定負荷５は停電時にも給電を確保したい負荷（例えば、照明器具、冷蔵庫など）の総称である。自立出力経路にはＡＣコンセントが設置されていてもよい。なお停電時において、一般負荷４全体をバックアップする構成の場合、インバータ１２の交流側の出力経路から自立出力経路を分岐させる必要はない。 The independent output path of the inverter 12 is connected to the specific load 5 via the independent output relay RY2. The specific load 5 is a general term for loads (e.g., lighting fixtures, refrigerators, etc.) to which a power supply needs to be ensured even during a power outage. An AC outlet may be installed on the independent output path. Note that in the case of a configuration in which the entire general load 4 is backed up during a power outage, there is no need to branch off the independent output path from the AC output path of the inverter 12.
　直流バスＢｄには、太陽電池６用のＤＣ／ＤＣコンバータ１１、定置用ＤＣ／ＤＣコンバータ２１および車載用ＤＣ／ＤＣコンバータ３１が並列に接続される。インバータ１２は、直流バスＢｄから供給される直流電力を交流電力に変換し、変換した交流電力を分電盤３または特定負荷５に出力する。また、インバータ１２は、系統２から分電盤３および連系リレーＲＹ１を介して供給される交流電力を直流電力に変換し、変換した直流電力を直流バスＢｄに出力することもできる。 A DC/DC converter 11 for the solar cell 6, a stationary DC/DC converter 21, and an on-board DC/DC converter 31 are connected in parallel to the DC bus Bd. The inverter 12 converts the DC power supplied from the DC bus Bd into AC power, and outputs the converted AC power to the distribution board 3 or the specific load 5. The inverter 12 can also convert the AC power supplied from the system 2 via the distribution board 3 and the interconnection relay RY1 into DC power, and output the converted DC power to the DC bus Bd.
　インバータ制御回路１４はインバータ１２を制御する。インバータ制御回路１４は系統連系時の基本制御として、直流バスＢｄの電圧が目標値を維持するようにインバータ１２を制御する。具体的にはインバータ制御回路１４は、直流バスＢｄの電圧を検出し、検出したバス電圧を目標値に一致させるための電流指令値を生成する。インバータ制御回路１４は、直流バスＢｄの電圧が目標値より高い場合はインバータ１２の出力電力を上げるための電流指令値を生成し、直流バスＢｄの電圧が目標値より低い場合はインバータ１２の出力電力を下げるための電流指令値を生成する。インバータ１２は、生成された電流指令値に基づく駆動信号に応じてスイッチング動作する。 The inverter control circuit 14 controls the inverter 12. As a basic control during system interconnection, the inverter control circuit 14 controls the inverter 12 so that the voltage of the DC bus Bd maintains a target value. Specifically, the inverter control circuit 14 detects the voltage of the DC bus Bd and generates a current command value for matching the detected bus voltage to the target value. If the voltage of the DC bus Bd is higher than the target value, the inverter control circuit 14 generates a current command value for increasing the output power of the inverter 12, and if the voltage of the DC bus Bd is lower than the target value, the inverter control circuit 14 generates a current command value for decreasing the output power of the inverter 12. The inverter 12 performs switching operation in response to a drive signal based on the generated current command value.
　制御部１５は電力変換システム１全体を統括的に制御する。制御部１５、インバータ制御回路１４、コンバータ制御回路１３、２２、３２は、ハードウェア資源とソフトウェア資源の協働、またはハードウェア資源のみにより実現できる。ハードウェア資源としてアナログ回路、ロジック回路、マイクロコントローラ、ＤＳＰ、ＲＯＭ、ＲＡＭ、ＡＳＩＣ、ＦＰＧＡ、その他のＬＳＩを利用できる。ソフトウェア資源として、ファームウェアなどのプログラムを利用できる。 The control unit 15 provides overall control of the entire power conversion system 1. The control unit 15, inverter control circuit 14, and converter control circuits 13, 22, and 32 can be realized by a combination of hardware and software resources, or by hardware resources alone. Hardware resources that can be used include analog circuits, logic circuits, microcontrollers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs. Software resources that can be used include programs such as firmware.
　系統連系モードでは、制御部１５は連系リレーＲＹ１をオン（クローズ）および自立出力リレーＲＹ２をオフ（オープン）に制御する。停電時の自立運転モードでは、制御部１５は連系リレーＲＹ１をオフおよび自立出力リレーＲＹ２をオンに制御する。制御部１５は、インバータ１２の交流側の測定電圧をもとに、系統２の停電を検出することができる。制御部１５は停電を検出すると、系統連系モードから自立運転モードに切り替える。自立運転モードでは、制御部１５は、インバータ１２から系統周波数および系統電圧に対応する交流電圧を出力させるように、インバータ制御回路１４を制御する。 In the grid-connected mode, the control unit 15 controls the grid-connected relay RY1 to be on (closed) and the independent output relay RY2 to be off (open). In the independent operation mode during a power outage, the control unit 15 controls the grid-connected relay RY1 to be off and the independent output relay RY2 to be on. The control unit 15 can detect a power outage in the grid 2 based on the measured voltage on the AC side of the inverter 12. When the control unit 15 detects a power outage, it switches from the grid-connected mode to the independent operation mode. In the independent operation mode, the control unit 15 controls the inverter control circuit 14 to cause the inverter 12 to output an AC voltage corresponding to the grid frequency and grid voltage.
　リモートコントローラ１６は、電力変換システム１の状態を表示するとともに、ユーザからの操作を受け付け、受け付けた操作にもとづく操作信号を制御部１５に送信する。 The remote controller 16 displays the status of the power conversion system 1, accepts operations from the user, and transmits operation signals based on the accepted operations to the control unit 15.
　定置用蓄電池７は電力を充放電可能であり、リチウムイオン蓄電池、ニッケル水素蓄電池、鉛蓄電池などの蓄電池を備える。なお蓄電池の代わりに、電気二重層キャパシタ、リチウムイオンキャパシタなどのスーパーキャパシタを備えていてもよい。 The stationary storage battery 7 is capable of charging and discharging power, and includes a storage battery such as a lithium ion storage battery, a nickel metal hydride storage battery, or a lead storage battery. Note that instead of a storage battery, a supercapacitor such as an electric double layer capacitor or a lithium ion capacitor may also be included.
　定置用蓄電池７は、定置用ＤＣ／ＤＣコンバータ２１と接続され、定置用ＤＣ／ＤＣコンバータ２１により充放電制御される。定置用ＤＣ／ＤＣコンバータ２１は、定置用蓄電池７と直流バスＢｄとの間に接続され、定置用蓄電池７を充放電するための双方向ＤＣ／ＤＣコンバータである。 The stationary storage battery 7 is connected to a stationary DC/DC converter 21, and charging and discharging are controlled by the stationary DC/DC converter 21. The stationary DC/DC converter 21 is connected between the stationary storage battery 7 and the DC bus Bd, and is a bidirectional DC/DC converter for charging and discharging the stationary storage battery 7.
　定置用コンバータ制御回路２２は定置用ＤＣ／ＤＣコンバータ２１を制御する。定置用コンバータ制御回路２２は基本制御として、制御部１５から通信線を介して送信されてくる指令値をもとに定置用ＤＣ／ＤＣコンバータ２１を充放電制御する。充放電制御として例えば、定電流（ＣＣ）制御や定電圧（ＣＶ）制御が可能である。また、定置用コンバータ制御回路２２は直流バスＢｄの電圧を監視し、バス電圧に応じて定置用ＤＣ／ＤＣコンバータ２１の電流指令値を適応的に変化させる制御も可能である。 The stationary converter control circuit 22 controls the stationary DC/DC converter 21. As a basic control, the stationary converter control circuit 22 controls the charging and discharging of the stationary DC/DC converter 21 based on command values transmitted from the control unit 15 via a communication line. For example, constant current (CC) control and constant voltage (CV) control are possible as charge and discharge control. The stationary converter control circuit 22 also monitors the voltage of the DC bus Bd, and can control the stationary DC/DC converter 21 to adaptively change the current command value according to the bus voltage.
　車載蓄電池８は、電動車に搭載される駆動用蓄電池であり、リチウムイオン蓄電池、ニッケル水素蓄電池などが使用される。電動車と電力変換システム１は充電ケーブルで接続される。車載蓄電池８は、電動車が自宅に駐車時に車載用ＤＣ／ＤＣコンバータ３１と接続され、車載用ＤＣ／ＤＣコンバータ３１により充放電制御される。車載用ＤＣ／ＤＣコンバータ３１は、車載蓄電池３０と直流バスＢｄとの間に接続され、電動車が自宅に駐車時に車載蓄電池３０を充放電する双方向ＤＣ／ＤＣコンバータである。 The on-board storage battery 8 is a drive storage battery mounted on the electric vehicle, and may be a lithium-ion storage battery, a nickel-metal hydride storage battery, or the like. The electric vehicle and the power conversion system 1 are connected by a charging cable. The on-board storage battery 8 is connected to an on-board DC/DC converter 31 when the electric vehicle is parked at home, and charging and discharging are controlled by the on-board DC/DC converter 31. The on-board DC/DC converter 31 is a bidirectional DC/DC converter that is connected between the on-board storage battery 30 and the DC bus Bd, and charges and discharges the on-board storage battery 30 when the electric vehicle is parked at home.
　車載用コンバータ制御回路３２は車載用ＤＣ／ＤＣコンバータ３１を制御する。車載用コンバータ制御回路３２は基本制御として、制御部１５から通信線を介して送信されてくる指令値、または電動車から充電ケーブル内の通信線を介して送信されてくる指令値をもとに車載用ＤＣ／ＤＣコンバータ３１を充放電制御する。充放電制御として例えば、定電流（ＣＣ）制御や定電圧（ＣＶ）制御が可能である。また、車載用コンバータ制御回路３２は直流バスＢｄの電圧を監視し、バス電圧に応じて車載用ＤＣ／ＤＣコンバータ３１の電流指令値を適応的に変化させる制御も可能である。 The on-board converter control circuit 32 controls the on-board DC/DC converter 31. As a basic control, the on-board converter control circuit 32 controls the charging and discharging of the on-board DC/DC converter 31 based on a command value sent from the control unit 15 via a communication line, or a command value sent from the electric vehicle via a communication line in the charging cable. As charge and discharge control, for example, constant current (CC) control and constant voltage (CV) control are possible. The on-board converter control circuit 32 can also monitor the voltage of the DC bus Bd, and adaptively change the current command value of the on-board DC/DC converter 31 according to the bus voltage.
　図２は、実施の形態に係る電力変換システム１の構成例２を説明するための図である。構成例２では、太陽電池６が設置されず、電力変換システム１はＤＣ／ＤＣコンバータ１１およびコンバータ制御回路１３を含まない。その他の構成は、図１に示した構成例１と同様である。 FIG. 2 is a diagram for explaining a configuration example 2 of a power conversion system 1 according to an embodiment. In the configuration example 2, a solar cell 6 is not installed, and the power conversion system 1 does not include a DC/DC converter 11 and a converter control circuit 13. The other configurations are the same as those of the configuration example 1 shown in FIG. 1.
　構成例１、構成例２のいずれにおいても、制御部１５は、系統２の停電を検出すると、インバータ制御回路１４に自立運転命令を送信する。本実施の形態では、インバータ１２の自立運転中、定置用蓄電池７から車載蓄電池８への電力融通、または車載蓄電池８から定置用蓄電池７への電力融通を実施することができる。ユーザは、リモートコントローラ１６から融通元の蓄電池と、融通先の蓄電池を指定する。制御部１５は、融通元のコンバータ制御回路に放電指令を送信し、融通先のコンバータ制御回路に充電指令を送信する。 In both configuration example 1 and configuration example 2, when the control unit 15 detects a power outage in the system 2, it sends an independent operation command to the inverter control circuit 14. In this embodiment, during independent operation of the inverter 12, power can be transferred from the stationary storage battery 7 to the vehicle storage battery 8, or from the vehicle storage battery 8 to the stationary storage battery 7. The user specifies the source storage battery and the destination storage battery from the remote controller 16. The control unit 15 sends a discharge command to the source converter control circuit and a charge command to the destination converter control circuit.
　インバータ１２の自立運転中に定置用蓄電池７と車載蓄電池８間で電力融通する場合、定置用コンバータ制御回路２２は、定置用蓄電池７の定格電力を超えず、かつ直流バスＢｄの設定された上限電圧と下限電圧の範囲を外れないように、定置用ＤＣ／ＤＣコンバータ２１から直流バスＢｄへの出力電力（直流バスＢｄから定置用ＤＣ／ＤＣコンバータ２１への入力電力）を制御する。 When power is exchanged between the stationary storage battery 7 and the vehicle storage battery 8 during independent operation of the inverter 12, the stationary converter control circuit 22 controls the output power from the stationary DC/DC converter 21 to the DC bus Bd (the input power from the DC bus Bd to the stationary DC/DC converter 21) so as not to exceed the rated power of the stationary storage battery 7 and not to deviate from the range of the set upper and lower voltage limits of the DC bus Bd.
　定置用蓄電池７が融通元に指定されている場合、基本的に、定置用ＤＣ／ＤＣコンバータ２１から直流バスＢｄへの出力電力は正（放電）となる。定置用蓄電池７が融通先に指定されている場合、基本的に、定置用ＤＣ／ＤＣコンバータ２１から直流バスＢｄへの出力電力は負（充電）となる。なお、特定負荷５の消費電力が増加した場合、定置用蓄電池７が融通先に指定されている場合でも、定置用ＤＣ／ＤＣコンバータ２１から直流バスＢｄへの出力電力が正（放電）に制御される場合がある。また構成例１において、太陽電池６の発電電力が増加した場合、定置用蓄電池７が融通元に指定されている場合でも、定置用ＤＣ／ＤＣコンバータ２１から直流バスＢｄへの出力電力が負（充電）に制御される場合がある。 When the stationary storage battery 7 is designated as the transfer source, the output power from the stationary DC/DC converter 21 to the DC bus Bd is basically positive (discharging). When the stationary storage battery 7 is designated as the transfer destination, the output power from the stationary DC/DC converter 21 to the DC bus Bd is basically negative (charging). Note that if the power consumption of the specific load 5 increases, the output power from the stationary DC/DC converter 21 to the DC bus Bd may be controlled to be positive (discharging) even if the stationary storage battery 7 is designated as the transfer destination. Also, in configuration example 1, if the power generation power of the solar cell 6 increases, the output power from the stationary DC/DC converter 21 to the DC bus Bd may be controlled to be negative (charging) even if the stationary storage battery 7 is designated as the transfer source.
　同様に車載用コンバータ制御回路３２は、車載蓄電池８の定格電力を超えず、かつ直流バスＢｄの設定された上限電圧と下限電圧の範囲を外れないように、車載用ＤＣ／ＤＣコンバータ３１から直流バスＢｄへの出力電力（直流バスＢｄから車載用ＤＣ／ＤＣコンバータ３１への入力電力）を制御する。 Similarly, the vehicle-mounted converter control circuit 32 controls the output power from the vehicle-mounted DC/DC converter 31 to the DC bus Bd (the input power from the DC bus Bd to the vehicle-mounted DC/DC converter 31) so as not to exceed the rated power of the vehicle-mounted storage battery 8 and not to deviate from the range of the set upper and lower limit voltages of the DC bus Bd.
　車載蓄電池８が融通元に指定されている場合、基本的に、車載用ＤＣ／ＤＣコンバータ３１から直流バスＢｄへの出力電力は正（放電）となり、車載蓄電池８が融通先に指定されている場合、基本的に、車載用ＤＣ／ＤＣコンバータ３１から直流バスＢｄへの出力電力は負（充電）となる。なお、特定負荷５の消費電力が増加した場合、車載蓄電池８が融通先に指定されている場合でも、車載用ＤＣ／ＤＣコンバータ３１から直流バスＢｄへの出力電力が正（放電）に制御される場合がある。また構成例１において、太陽電池６の発電電力が増加した場合、車載蓄電池８が融通元に指定されている場合でも、車載用ＤＣ／ＤＣコンバータ３１から直流バスＢｄへの出力電力が負（充電）に制御される場合がある。 When the on-board storage battery 8 is designated as the transfer source, the output power from the on-board DC/DC converter 31 to the DC bus Bd is basically positive (discharging), and when the on-board storage battery 8 is designated as the transfer destination, the output power from the on-board DC/DC converter 31 to the DC bus Bd is basically negative (charging). Note that if the power consumption of the specific load 5 increases, the output power from the on-board DC/DC converter 31 to the DC bus Bd may be controlled to be positive (discharging) even if the on-board storage battery 8 is designated as the transfer destination. Also, in configuration example 1, if the power generation power of the solar cell 6 increases, the output power from the on-board DC/DC converter 31 to the DC bus Bd may be controlled to be negative (charging) even if the on-board storage battery 8 is designated as the transfer source.
　図３は、自立運転中に、定置用蓄電池７から車載蓄電池８へ電力融通する場合の、バス電圧、インバータ１２の自立出力、定置用ＤＣ／ＤＣコンバータ２１の出力および車載用ＤＣ／ＤＣコンバータ３１の出力の遷移の一例を示す。図３に示す例では、太陽電池６が非接続、インバータ１２の自立出力（特定負荷５の消費電力）が１ｋＷ、定置用蓄電池７の定格電力が±３ｋｗ、車載蓄電池８の定格電力が±６ｋｗとする。 Figure 3 shows an example of transitions in bus voltage, the independent output of inverter 12, the output of stationary DC/DC converter 21, and the output of on-board DC/DC converter 31 when power is transferred from stationary storage battery 7 to on-board storage battery 8 during independent operation. In the example shown in Figure 3, it is assumed that solar cell 6 is not connected, the independent output of inverter 12 (power consumption of specific load 5) is 1 kW, the rated power of stationary storage battery 7 is ±3 kW, and the rated power of on-board storage battery 8 is ±6 kW.
　制御部１５は系統２の停電を検出すると、連系リレーＲＹ１とターンオフして自立運転の準備を開始する。自立運転の準備期間において、定置用蓄電池７または車載蓄電池８の出力電圧により、直流バスＢｄの電圧が３６０Ｖに維持される。制御部１５は、自立出力リレーＲＹ２をターンオンして自立運転を開始する。定置用ＤＣ／ＤＣコンバータ２１は、定置用蓄電池７から直流バスＢｄに放電を開始する。車載用ＤＣ／ＤＣコンバータ３１は、直流バスＢｄから車載蓄電池８に充電を開始する。 When the control unit 15 detects a power outage in system 2, it turns off the interconnection relay RY1 and starts preparation for independent operation. During the preparation period for independent operation, the voltage of the DC bus Bd is maintained at 360V by the output voltage of the stationary storage battery 7 or the vehicle-mounted storage battery 8. The control unit 15 turns on the independent output relay RY2 to start independent operation. The stationary DC/DC converter 21 starts discharging from the stationary storage battery 7 to the DC bus Bd. The vehicle-mounted DC/DC converter 31 starts charging from the DC bus Bd to the vehicle-mounted storage battery 8.
　直流バスＢｄの電圧が設定上限電圧または設定下限電圧に到達する前に、定置用ＤＣ／ＤＣコンバータ２１の出力電力が定置用蓄電池７の定格電力に到達するため、定置用コンバータ制御回路２２は、定置用ＤＣ／ＤＣコンバータ２１の出力電力を定置用蓄電池７の定格電力に維持する。 Because the output power of the stationary DC/DC converter 21 reaches the rated power of the stationary storage battery 7 before the voltage of the DC bus Bd reaches the set upper limit voltage or the set lower limit voltage, the stationary converter control circuit 22 maintains the output power of the stationary DC/DC converter 21 at the rated power of the stationary storage battery 7.
　車載用コンバータ制御回路３２は、直流バスＢｄの電圧が設定下限電圧に到達すると、直流バスＢｄの電圧が設定下限電圧を下回らないように、車載蓄電池８への充電量を減少させる。充電量を０Ｗまで減少させても直流バスＢｄの電圧低下が止まらない場合、車載用コンバータ制御回路３２は、充電から放電に切り替える。 When the voltage of the DC bus Bd reaches the set lower limit voltage, the in-vehicle converter control circuit 32 reduces the amount of charge to the in-vehicle storage battery 8 so that the voltage of the DC bus Bd does not fall below the set lower limit voltage. If the voltage drop of the DC bus Bd does not stop even when the amount of charge is reduced to 0 W, the in-vehicle converter control circuit 32 switches from charging to discharging.
　図４は、自立運転中に、車載蓄電池８から定置用蓄電池７へ電力融通する場合の、バス電圧、インバータ１２の自立出力、定置用ＤＣ／ＤＣコンバータ２１の出力および車載用ＤＣ／ＤＣコンバータ３１の出力の遷移の一例を示す。前提条件は図３の例と同じとする。 Figure 4 shows an example of the transition of the bus voltage, the independent output of the inverter 12, the output of the stationary DC/DC converter 21, and the output of the vehicle-mounted DC/DC converter 31 when power is transferred from the vehicle-mounted storage battery 8 to the stationary storage battery 7 during independent operation. The prerequisites are the same as those in the example of Figure 3.
　制御部１５は系統２の停電を検出すると、連系リレーＲＹ１とターンオフして自立運転の準備を開始する。自立運転の準備期間において、定置用蓄電池７または車載蓄電池８の出力電圧により、直流バスＢｄの電圧が３６０Ｖに維持される。制御部１５は、自立出力リレーＲＹ２をターンオンして自立運転を開始する。定置用ＤＣ／ＤＣコンバータ２１は、直流バスＢｄから定置用蓄電池７に充電を開始する。車載用ＤＣ／ＤＣコンバータ３１は、車載蓄電池８から直流バスＢｄに放電を開始する。 When the control unit 15 detects a power outage in system 2, it turns off the interconnection relay RY1 and starts preparation for independent operation. During the preparation period for independent operation, the voltage of the DC bus Bd is maintained at 360V by the output voltage of the stationary storage battery 7 or the vehicle-mounted storage battery 8. The control unit 15 turns on the independent output relay RY2 to start independent operation. The stationary DC/DC converter 21 starts charging the stationary storage battery 7 from the DC bus Bd. The vehicle-mounted DC/DC converter 31 starts discharging from the vehicle-mounted storage battery 8 to the DC bus Bd.
　直流バスＢｄの電圧が設定上限電圧または設定下限電圧に到達する前に、定置用ＤＣ／ＤＣコンバータ２１の入力電力が定置用蓄電池７の定格電力に到達するため、定置用コンバータ制御回路２２は、定置用ＤＣ／ＤＣコンバータ２１の入力電力を定置用蓄電池７の定格電力に維持する。 Because the input power of the stationary DC/DC converter 21 reaches the rated power of the stationary storage battery 7 before the voltage of the DC bus Bd reaches the set upper limit voltage or the set lower limit voltage, the stationary converter control circuit 22 maintains the input power of the stationary DC/DC converter 21 at the rated power of the stationary storage battery 7.
　車載用コンバータ制御回路３２は、直流バスＢｄの電圧が設定上限電圧に到達すると、直流バスＢｄの電圧が設定上限電圧を上回らないように、車載蓄電池８からの放電量を減少させる。 When the voltage of the DC bus Bd reaches the set upper limit voltage, the vehicle converter control circuit 32 reduces the amount of discharge from the vehicle storage battery 8 so that the voltage of the DC bus Bd does not exceed the set upper limit voltage.
　以上の例では、定置用ＤＣ／ＤＣコンバータ２１の出力電力の最大値を定置用蓄電池７の定格電力に、車載用ＤＣ／ＤＣコンバータ３１の出力電力の最大値を車載蓄電池８の定格電力にそれぞれ制限する例を説明した。この点、ユーザが、インバータ１２の自立運転中に定置用蓄電池７と車載蓄電池８間で電力融通する場合の最大電力値を指定してもよい。この場合、定置用ＤＣ／ＤＣコンバータ２１の出力電力および車載用ＤＣ／ＤＣコンバータ３１の出力電力の最大値は、ユーザにより指定された最大電力値に制限される。緊急性が低い場合は、低レートで電力移動することで、蓄電池の劣化抑制を優先することもできる。 In the above example, the maximum value of the output power of the stationary DC/DC converter 21 is limited to the rated power of the stationary storage battery 7, and the maximum value of the output power of the vehicle-mounted DC/DC converter 31 is limited to the rated power of the vehicle-mounted storage battery 8. In this regard, the user may specify the maximum power value when power is exchanged between the stationary storage battery 7 and the vehicle-mounted storage battery 8 during independent operation of the inverter 12. In this case, the maximum values of the output power of the stationary DC/DC converter 21 and the output power of the vehicle-mounted DC/DC converter 31 are limited to the maximum power value specified by the user. When urgency is low, power can be transferred at a low rate to prioritize suppression of deterioration of the storage batteries.
　定置用ＤＣ／ＤＣコンバータ２１の出力電力が定置用蓄電池７の定格電力を超えず、車載用ＤＣ／ＤＣコンバータ３１の出力電力が車載蓄電池８の定格電力を超えない場合、定置用ＤＣ／ＤＣコンバータ２１と車載用ＤＣ／ＤＣコンバータ３１のいずれのコンバータが、バス電圧を制御するか決定する必要がある。これに対して、所定の傾きを持つバス電圧－出力電力特性を使用することで、バス電圧を制御するコンバータを一つに決定することができる。 If the output power of the stationary DC/DC converter 21 does not exceed the rated power of the stationary storage battery 7, and the output power of the vehicle-mounted DC/DC converter 31 does not exceed the rated power of the vehicle-mounted storage battery 8, it is necessary to determine which converter, the stationary DC/DC converter 21 or the vehicle-mounted DC/DC converter 31, will control the bus voltage. By using a bus voltage-output power characteristic with a predetermined slope, it is possible to determine one converter to control the bus voltage.
　図５は、コンバータのバス電圧－出力電力特性を一次関数で規定した例を示す。図５に示す例では、定置用コンバータ制御回路２２は、定置用ＤＣ／ＤＣコンバータ２１の出力電力が大きいほど、定置用ＤＣ／ＤＣコンバータ２１の設定上限電圧および設定下限電圧をそれぞれ、低く設定する。同様に車載用コンバータ制御回路３２は、車載用ＤＣ／ＤＣコンバータ３１の出力電力が大きいほど、車載用ＤＣ／ＤＣコンバータ３１の設定上限電圧および設定下限電圧をそれぞれ、低く設定する。この例では、バス電圧が設定上限電圧に到達した場合は充電側のＤＣ／ＤＣコンバータで、バス電圧が設定下限電圧に到達した場合は放電側のＤＣ／ＤＣコンバータでバス電圧を制御する。 Figure 5 shows an example in which the converter bus voltage-output power characteristics are defined by a linear function. In the example shown in Figure 5, the stationary converter control circuit 22 sets the set upper limit voltage and set lower limit voltage of the stationary DC/DC converter 21 lower as the output power of the stationary DC/DC converter 21 is higher. Similarly, the vehicle converter control circuit 32 sets the set upper limit voltage and set lower limit voltage of the vehicle DC/DC converter 31 lower as the output power of the vehicle DC/DC converter 31 is higher. In this example, the bus voltage is controlled by the charging side DC/DC converter when the bus voltage reaches the set upper limit voltage, and by the discharging side DC/DC converter when the bus voltage reaches the set lower limit voltage.
　以上の例では、定置用コンバータ制御回路２２が直流バスＢｄの電力を測定して定置用ＤＣ／ＤＣコンバータ２１の充放電量（電流指令値）を適応的に制御する、または車載用コンバータ制御回路３２が直流バスＢｄの電力を測定して、車載用ＤＣ／ＤＣコンバータ３１の充放電量（電流指令値）を適応的に制御することを想定した。この点、インバータ制御回路１４が直流バスＢｄの電力を測定し、制御部１５が定置用ＤＣ／ＤＣコンバータ２１の充放電量（電流指令値）または車載用ＤＣ／ＤＣコンバータ３１の充放電量（電流指令値）を適応的に決定し、高速通信で定置用コンバータ制御回路２２または車載用コンバータ制御回路３２に充放電量（電流指令値）を送信する構成でもよい。 In the above examples, it is assumed that the stationary converter control circuit 22 measures the power of the DC bus Bd and adaptively controls the charge/discharge amount (current command value) of the stationary DC/DC converter 21, or that the vehicle-mounted converter control circuit 32 measures the power of the DC bus Bd and adaptively controls the charge/discharge amount (current command value) of the vehicle-mounted DC/DC converter 31. In this regard, it is also possible to configure the inverter control circuit 14 to measure the power of the DC bus Bd, and the control unit 15 to adaptively determine the charge/discharge amount (current command value) of the stationary DC/DC converter 21 or the charge/discharge amount (current command value) of the vehicle-mounted DC/DC converter 31, and to transmit the charge/discharge amount (current command value) to the stationary converter control circuit 22 or the vehicle-mounted converter control circuit 32 via high-speed communication.
　以上説明したように本実施の形態によれば、インバータ１２の自立運転中に、電力変換システム１に接続された複数の蓄電池間で電力移動を可能とすることで、ユーザの利便性を向上させることができる。例えば、停電時において、他の場所で充電した車載蓄電池８の電力を自立運転しながら定置用蓄電池７に充電することができる。また、太陽電池６の発電電力で充電した定置用蓄電池７の電力を自立運転しながら車載蓄電池８に充電することができる。 As described above, according to this embodiment, by enabling power transfer between multiple storage batteries connected to the power conversion system 1 during independent operation of the inverter 12, it is possible to improve user convenience. For example, during a power outage, it is possible to charge the stationary storage battery 7 with power from the vehicle-mounted storage battery 8 charged at another location while the system is operating independently. In addition, it is possible to charge the stationary storage battery 7 with power generated by the solar cell 6 while the system is operating independently.
　以上、本開示を実施の形態をもとに説明した。実施の形態は例示であり、それらの各構成要素や各処理プロセスの組み合わせにいろいろな変形例が可能なこと、またそうした変形例も本開示の範囲にあることは当業者に理解されるところである。 The present disclosure has been described above based on the embodiments. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each processing process, and that such modifications are also within the scope of the present disclosure.
　上述の実施の形態では、インバータ１２の自立運転中に複数の蓄電池間で電力移動する制御を説明した。この点、系統連系運転中の逆潮流期間においても、上述した複数の蓄電池間で電力移動する制御を実施してもよい。 In the above embodiment, the control of transferring power between multiple storage batteries during independent operation of the inverter 12 has been described. In this regard, the control of transferring power between the above-mentioned multiple storage batteries may also be implemented during a reverse power flow period during grid-connected operation.
　上述の実施の形態では、２つの蓄電池が電力変換システム１に接続される例を説明した。この点、３つ以上の蓄電池が電力変換システム１に接続される場合も、上述した制御を適用可能である。ユーザが各蓄電池について放電か充電かを指定し、図５に示したバス電圧－出力電力特性を使用してバス電圧を制御するコンバータが一つに決定されることで、３つ以上の蓄電池間の電力移動が可能である。 In the above embodiment, an example has been described in which two storage batteries are connected to the power conversion system 1. In this regard, the above-mentioned control can also be applied when three or more storage batteries are connected to the power conversion system 1. The user specifies whether each storage battery is to be discharged or charged, and one converter is determined to control the bus voltage using the bus voltage-output power characteristics shown in Figure 5, making it possible to transfer power between three or more storage batteries.
　上述の実施の形態では、定置用蓄電池７と車載蓄電池８間の電力移動について説明したが、本開示は、定置用蓄電池間の電力移動にも適用可能である。例えば、定置用蓄電池が屋内と屋外に設置されている場合、気温が低い方の蓄電池に電力を移動させることで蓄電池の保存劣化を小さくすることができる。 In the above embodiment, the transfer of power between the stationary storage battery 7 and the vehicle-mounted storage battery 8 has been described, but the present disclosure is also applicable to the transfer of power between stationary storage batteries. For example, if stationary storage batteries are installed both indoors and outdoors, the storage deterioration of the storage batteries can be reduced by transferring power to the storage battery with the lower temperature.
　なお、実施の形態は、以下の項目によって特定されてもよい。 The embodiment may be specified by the following items:
［項目１］
　第１蓄電部（７）を充放電する第１ＤＣ／ＤＣコンバータ（２１）と、
　第２蓄電部（８）を充放電する第２ＤＣ／ＤＣコンバータ（３１）と、
　前記第１ＤＣ／ＤＣコンバータ（２１）および前記第２ＤＣ／ＤＣコンバータ（３１）が並列に接続される直流バス（Ｂｄ）と、
　前記直流バス（Ｂｄ）に接続されるインバータ（１２）と、を備え、
　前記インバータ（１２）が交流電力を出力中に、前記第１蓄電部（７）から前記第２蓄電部（８）へ電力移動が可能である電力変換システム（１）。
　これによれば、ユーザの利便性を向上させることができる。
［項目２］
　前記インバータ（１２）が自立運転中に、前記第１蓄電部（７）から前記第２蓄電部（８）へ電力移動が可能である項目１に記載の電力変換システム（１）。
　これによれば、停電時におけるユーザの利便性を向上させることができる。
［項目３］
　前記第１蓄電部（７）と前記第２蓄電部（８）の一方は車載蓄電池であり、他方は定置蓄電池である項目１または２に記載の電力変換システム（１）。
　これによれば、電動車を保有するユーザの利便性を向上させることができる。
［項目４］
　前記インバータ（１２）が交流電力を出力中に、前記第１蓄電部（７）から前記第２蓄電部（８）に電力を移動させる場合、前記第１ＤＣ／ＤＣコンバータ（２１）に放電指示が設定され、前記第２ＤＣ／ＤＣコンバータ（３１）に充電指示が設定され、
　前記第１ＤＣ／ＤＣコンバータ（２１）は、前記第１蓄電部（７）の定格電力または指定された電力を超えず、かつ前記直流バス（Ｂｄ）の設定された上限電圧と下限電圧の範囲を外れないように前記直流バス（Ｂｄ）への出力電力を制御し、
　前記第２ＤＣ／ＤＣコンバータ（３１）は、前記第２蓄電部（８）の定格電力または指定された電力を超えず、かつ前記直流バス（Ｂｄ）の設定された上限電圧と下限電圧の範囲を外れないように前記直流バス（Ｂｄ）からの入力電力を制御する、
　項目１または２に記載の電力変換システム（１）。
　これによれば、直流バス（Ｂｄ）の電圧を安定化させつつ、蓄電部間の電力移動が可能となる。
［項目５］
　前記第１ＤＣ／ＤＣコンバータ（２１）の出力電力が大きいほど、前記第１ＤＣ／ＤＣコンバータ（２１）の前記上限電圧および前記下限電圧はそれぞれ、低く設定され、
　前記第２ＤＣ／ＤＣコンバータ（３１）の出力電力が大きいほど、前記第２ＤＣ／ＤＣコンバータ（３１）の前記上限電圧および前記下限電圧はそれぞれ、低く設定される、
　項目４に記載の電力変換システム（１）。
　これによれば、直流バス（Ｂｄ）の電圧を制御するＤＣ／ＤＣコンバータを一つに特定することができる。 [Item 1]
a first DC/DC converter (21) for charging and discharging a first power storage unit (7);
a second DC/DC converter (31) that charges and discharges the second power storage unit (8);
a DC bus (Bd) to which the first DC/DC converter (21) and the second DC/DC converter (31) are connected in parallel;
an inverter (12) connected to the DC bus (Bd);
The power conversion system (1) is capable of transferring power from the first power storage unit (7) to the second power storage unit (8) while the inverter (12) is outputting AC power.
This can improve user convenience.
[Item 2]
2. The power conversion system (1) according to item 1, wherein power can be transferred from the first power storage unit (7) to the second power storage unit (8) during an independent operation of the inverter (12).
This can improve user convenience during a power outage.
[Item 3]
3. The power conversion system (1) according to item 1 or 2, wherein one of the first storage unit (7) and the second storage unit (8) is an in-vehicle storage battery, and the other is a stationary storage battery.
This can improve convenience for users who own electric vehicles.
[Item 4]
When power is transferred from the first power storage unit (7) to the second power storage unit (8) while the inverter (12) is outputting AC power, a discharge instruction is set to the first DC/DC converter (21) and a charge instruction is set to the second DC/DC converter (31);
the first DC/DC converter (21) controls an output power to the DC bus (Bd) so as not to exceed a rated power or a designated power of the first power storage unit (7) and not to deviate from a range between an upper limit voltage and a lower limit voltage set for the DC bus (Bd);
the second DC/DC converter (31) controls the input power from the DC bus (Bd) so that the input power does not exceed a rated power or a designated power of the second storage unit (8) and does not deviate from a range between an upper limit voltage and a lower limit voltage set for the DC bus (Bd);
3. The power conversion system (1) according to item 1 or 2.
This enables power transfer between the power storage units while stabilizing the voltage of the DC bus (Bd).
[Item 5]
the higher the output power of the first DC/DC converter (21), the lower the upper limit voltage and the lower limit voltage of the first DC/DC converter (21) are set,
The higher the output power of the second DC/DC converter (31), the lower the upper limit voltage and the lower limit voltage of the second DC/DC converter (31) are set.
5. The power conversion system (1) according to item 4.
This allows the DC/DC converter that controls the voltage of the DC bus (Bd) to be specified as one.
　本開示は、車載蓄電池と定置用蓄電池が並列に接続されたシステムに利用可能である。 This disclosure can be used in a system in which an on-board storage battery and a stationary storage battery are connected in parallel.
　１　電力変換システム、　２　系統、　３　分電盤、　４　一般負荷、　５　特定負荷、　６　太陽電池、　７　定置用蓄電池、　８　車載蓄電池、　１１　ＤＣ／ＤＣコンバータ、　１２　インバータ、　１３　コンバータ制御回路、　１４　インバータ制御回路、　１５　制御部、　１６　リモートコントローラ、　ＲＹ１　連系リレー、　ＲＹ２　自立出力リレー、　２１　定置用ＤＣ／ＤＣコンバータ、　２２　定置用コンバータ制御回路、　３１　車載用ＤＣ／ＤＣコンバータ、　３２　車載用コンバータ制御回路、　Ｂｄ　直流バス。 1 Power conversion system, 2 System, 3 Distribution board, 4 General load, 5 Specific load, 6 Solar cell, 7 Stationary storage battery, 8 Vehicle storage battery, 11 DC/DC converter, 12 Inverter, 13 Converter control circuit, 14 Inverter control circuit, 15 Control unit, 16 Remote controller, RY1 Grid-connection relay, RY2 Standalone output relay, 21 Stationary DC/DC converter, 22 Stationary converter control circuit, 31 Vehicle DC/DC converter, 32 Vehicle converter control circuit, Bd DC bus.

Claims (5)

  1. 　第１蓄電部を充放電する第１ＤＣ／ＤＣコンバータと、
    　第２蓄電部を充放電する第２ＤＣ／ＤＣコンバータと、
    　前記第１ＤＣ／ＤＣコンバータおよび前記第２ＤＣ／ＤＣコンバータが並列に接続される直流バスと、
    　前記直流バスに接続されるインバータと、を備え、
    　前記インバータが交流電力を出力中に、前記第１蓄電部から前記第２蓄電部へ電力移動が可能である電力変換システム。     a first DC/DC converter configured to charge and discharge the first power storage unit;
    a second DC/DC converter configured to charge and discharge the second power storage unit;
    a DC bus to which the first DC/DC converter and the second DC/DC converter are connected in parallel;
    an inverter connected to the DC bus;
    The power conversion system is capable of transferring power from the first power storage unit to the second power storage unit while the inverter is outputting AC power.
  2. 　前記インバータが自立運転中に、前記第１蓄電部から前記第２蓄電部へ電力移動が可能である請求項１に記載の電力変換システム。 The power conversion system according to claim 1, wherein power can be transferred from the first power storage unit to the second power storage unit while the inverter is operating independently.
  3. 　前記第１蓄電部と前記第２蓄電部の一方は車載蓄電池であり、他方は定置蓄電池である請求項１または２に記載の電力変換システム。 The power conversion system according to claim 1 or 2, wherein one of the first storage unit and the second storage unit is an on-board storage battery, and the other is a stationary storage battery.
  4. 　前記インバータが交流電力を出力中に、前記第１蓄電部から前記第２蓄電部に電力を移動させる場合、前記第１ＤＣ／ＤＣコンバータに放電指示が設定され、前記第２ＤＣ／ＤＣコンバータに充電指示が設定され、
    　前記第１ＤＣ／ＤＣコンバータは、前記第１蓄電部の定格電力または指定された電力を超えず、かつ前記直流バスの設定された上限電圧と下限電圧の範囲を外れないように前記直流バスへの出力電力を制御し、
    　前記第２ＤＣ／ＤＣコンバータは、前記第２蓄電部の定格電力または指定された電力を超えず、かつ前記直流バスの設定された上限電圧と下限電圧の範囲を外れないように前記直流バスからの入力電力を制御する、
    　請求項１または２に記載の電力変換システム。     when power is transferred from the first power storage unit to the second power storage unit while the inverter is outputting AC power, a discharge instruction is set to the first DC/DC converter and a charge instruction is set to the second DC/DC converter;
    the first DC/DC converter controls an output power to the DC bus so as not to exceed a rated power or a designated power of the first power storage unit and not to deviate from a range between an upper limit voltage and a lower limit voltage set for the DC bus;
    the second DC/DC converter controls the input power from the DC bus so as not to exceed a rated power or a designated power of the second power storage unit and not to deviate from a range between an upper limit voltage and a lower limit voltage set for the DC bus.
    The power conversion system according to claim 1 or 2.
  5. 　前記第１ＤＣ／ＤＣコンバータの出力電力が大きいほど、前記第１ＤＣ／ＤＣコンバータの前記上限電圧および前記下限電圧はそれぞれ、低く設定され、
    　前記第２ＤＣ／ＤＣコンバータの出力電力が大きいほど、前記第２ＤＣ／ＤＣコンバータの前記上限電圧および前記下限電圧はそれぞれ、低く設定される、
    　請求項４に記載の電力変換システム。     the upper limit voltage and the lower limit voltage of the first DC/DC converter are set lower as the output power of the first DC/DC converter is larger,
    the upper limit voltage and the lower limit voltage of the second DC/DC converter are set lower as the output power of the second DC/DC converter is higher.
    The power conversion system of claim 4 .
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012151938A (en) * 2011-01-17 2012-08-09 Jfe Engineering Corp Quick charger, load equalization method and quick charge method using the quick charger
JP2015106999A (en) * 2013-11-29 2015-06-08 住友電気工業株式会社 Power supply facility and operational method thereof
JP2018027016A (en) * 2016-11-29 2018-02-15 三菱重工業株式会社 Charging power control circuit and charging facility management device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012151938A (en) * 2011-01-17 2012-08-09 Jfe Engineering Corp Quick charger, load equalization method and quick charge method using the quick charger
JP2015106999A (en) * 2013-11-29 2015-06-08 住友電気工業株式会社 Power supply facility and operational method thereof
JP2018027016A (en) * 2016-11-29 2018-02-15 三菱重工業株式会社 Charging power control circuit and charging facility management device

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