WO2018179716A1 - Power conversion device, power conversion system - Google Patents

Power conversion device, power conversion system Download PDF

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Publication number
WO2018179716A1
WO2018179716A1 PCT/JP2018/001806 JP2018001806W WO2018179716A1 WO 2018179716 A1 WO2018179716 A1 WO 2018179716A1 JP 2018001806 W JP2018001806 W JP 2018001806W WO 2018179716 A1 WO2018179716 A1 WO 2018179716A1
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WIPO (PCT)
Prior art keywords
power
output
converter
inverter
bus
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PCT/JP2018/001806
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French (fr)
Japanese (ja)
Inventor
菊池　彰洋
渉 堀尾
藤井　裕之
賢治 花村
智規 伊藤
康太 前場
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パナソニックＩｐマネジメント株式会社
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Publication of WO2018179716A1 publication Critical patent/WO2018179716A1/en

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    • 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
    • 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
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a power conversion device and a power conversion system that convert DC power into AC power.
  • distributed power sources that are grid-connected include solar cells, fuel cells, stationary storage batteries, and in-vehicle storage batteries as power sources.
  • a typical configuration of a distributed power supply system connected to a system is a configuration in which a single distributed power supply is used to connect the system via a DC-DC converter, a DC bus and an inverter, and a plurality of distributed power supplies. Are connected to each other via each DC-DC converter, a common DC bus, and one inverter (see, for example, Patent Document 1).
  • the DC-DC converter and the inverter are physically installed in a single housing, the DC-DC converter and the inverter are controlled independently by separate control devices (for example, a microcomputer). Sometimes it is done. In such a distributed power supply system in which the DC-DC converter and the inverter are physically or controlly separated, the inverter and various distributed power supplies can be freely combined.
  • Integral distributed power supply system basically manages all information in a single control unit and adjusts the input / output power of the system according to the situation.
  • adaptive suppression control is performed on the input side and / or output side, and control is performed so that power balance of the entire system is maintained.
  • each control unit is separated, and it is difficult to collectively control the input / output power of the system. If appropriate suppression control is not performed in response to suppression instructions corresponding to various output suppression reasons, the power balance of the entire system is lost.
  • This invention is made
  • the objective is to provide the power converter device and power conversion system which can perform exact output suppression control with respect to generation
  • a power converter converts a voltage of DC power output from a power generator that generates power based on renewable energy, and outputs the converted DC power to a DC bus.
  • a first DC-DC converter an inverter connected to the first DC-DC converter via the DC bus, converting DC power of the DC bus into AC power, and supplying the converted AC power to a load or a power system
  • a control circuit for controlling the inverter The said control circuit changes the amount of suppression of the output of the said inverter according to the classification of the output suppression reason of this power converter device.
  • FIGS. 2A and 2B are diagrams schematically illustrating the state of the voltage of the DC bus.
  • Drawing 3 (a) and (b) is a figure showing an example of an output control reason when the 2nd power converter is in a disconnection state, and an output control reason when the 2nd power converter is in a connection state. It is a figure which shows an example of the output of an inverter in case multiple types of output suppression reasons generate
  • FIG. 1 is a diagram for explaining a power conversion system 1 according to an embodiment of the present invention.
  • the power conversion system 1 includes a first power conversion device 10 and a second power conversion device 20.
  • the first power conversion device 10 is a power conditioner system for the solar cell 2
  • the second power conversion device 20 is a power conditioner system for the power storage unit 3.
  • FIG. 1 the example which retrofitted the power conditioner system for the electrical storage part 3 to the power conditioner system for the solar cells 2 is shown.
  • the solar cell 2 is a power generation device that directly converts light energy into electric power using the photovoltaic effect.
  • a silicon solar cell, a solar cell made of a compound semiconductor or the like, a dye-sensitized type (organic solar cell), or the like is used as the solar cell 2.
  • the solar cell 2 is connected to the first power conversion device 10 and outputs the generated power to the first power conversion device 10.
  • the first power converter 10 includes a DC-DC converter 11, a converter control circuit 12, an inverter 13, a temperature sensor T1, an inverter control circuit 14, and a system control circuit 15.
  • the system control circuit 15 includes an output suppression control unit 15a and a command value generation unit 15b.
  • the DC-DC converter 11 and the inverter 13 are connected by a DC bus 40.
  • the converter control circuit 12 and the system control circuit 15 are connected by a communication line 41, and communication conforming to a predetermined serial communication standard (for example, RS-485 standard, TCP-IP standard) is performed between the two.
  • a predetermined serial communication standard for example, RS-485 standard, TCP-IP standard
  • the DC-DC converter 11 converts the DC power output from the solar cell 2 into DC power having a desired voltage value, and outputs the converted DC power to the DC bus 40.
  • the DC-DC converter 11 can be constituted by a step-up chopper, for example.
  • the converter control circuit 12 controls the DC-DC converter 11. As a basic control, the converter control circuit 12 performs MPPT (Maximum Power Point Tracking) control of the DC-DC converter 11 so that the output power of the solar cell 2 is maximized. Specifically, converter control circuit 12 measures the input voltage and input current of DC-DC converter 11, which are the output voltage and output current of solar cell 2, and estimates the generated power of solar cell 2. The converter control circuit 12 generates a command value for setting the generated power of the solar battery 2 to the maximum power point (optimum operating point) based on the measured output voltage of the solar battery 2 and the estimated generated power.
  • MPPT Maximum Power Point Tracking
  • the maximum power point is searched by changing the operating point voltage with a predetermined step width according to the hill-climbing method, and the command value is generated so as to maintain the maximum power point.
  • the DC-DC converter 11 performs a switching operation according to a drive signal based on the generated command value.
  • the inverter 13 is a bidirectional inverter that converts DC power input from the DC bus 40 into AC power and outputs the converted AC power to a distribution line 50 connected to a commercial power system (hereinafter simply referred to as system 4). To do. A load 5 is connected to the distribution line 50. Further, the inverter 13 converts AC power supplied from the system 4 into DC power, and outputs the converted DC power to the DC bus 40. A smoothing electrolytic capacitor (not shown) is connected to the DC bus 40.
  • the inverter control circuit 14 controls the inverter 13. As a basic control, the inverter control circuit 14 controls the inverter 13 so that the voltage of the DC bus 40 maintains the first threshold voltage. Specifically, the inverter control circuit 14 detects the voltage of the DC bus 40 and generates a command value for making the detected bus voltage coincide with the first threshold voltage. The inverter control circuit 14 generates a command value for increasing the duty ratio of the inverter 13 when the voltage of the DC bus 40 is higher than the first threshold voltage, and the inverter control circuit 14 when the voltage of the DC bus 40 is lower than the first threshold voltage. A command value for lowering the duty ratio of 13 is generated. The inverter 13 performs a switching operation according to a drive signal based on the generated command value.
  • the temperature sensor T1 detects the temperature in the first power converter 10 and outputs it to the system control circuit 15.
  • a thermistor, a thermocouple, or the like can be used as the temperature sensor T1.
  • the power storage unit 3 can charge and discharge electric power, and includes a lithium ion storage battery, a nickel hydride storage battery, a lead storage battery, an electric double layer capacitor, a lithium ion capacitor, and the like.
  • the power storage unit 3 is connected to the second power conversion device 20.
  • the second power conversion device 20 includes a DC-DC converter 21 and a converter control circuit 22.
  • the converter control circuit 22 and the system control circuit 15 of the first power conversion device 10 are connected by a communication line 42, and communication based on a predetermined serial communication standard is performed between them.
  • the DC-DC converter 21 is a bidirectional converter that is connected between the power storage unit 3 and the DC bus 40 and charges and discharges the power storage unit 3.
  • the converter control circuit 22 controls the DC-DC converter 21.
  • the converter control circuit 22 controls the DC-DC converter 21 based on the command value transmitted from the system control circuit 15 to control the power storage unit 3 at a constant current (CC) / constant voltage (CV).
  • CC constant current
  • CV constant voltage
  • Charge / discharge For example, the converter control circuit 22 receives a power command value from the system control circuit 15 at the time of discharging, and uses a value obtained by dividing the power command value by the voltage of the power storage unit 3 as a current command value. Discharge.
  • the system control circuit 15 receives an instruction related to the output power amount and output timing to the grid 4 from a grid operating organization such as a power company via an external network (for example, the Internet or a dedicated line).
  • a grid operating organization such as a power company
  • an external network for example, the Internet or a dedicated line
  • the system control circuit 15 of the first power converter 10 is based on the measured value of a CT sensor (not shown) installed on the system 4 side of the distribution line 50 from the distribution board. Detect reverse power flow.
  • the converter control circuit 22 of the second power conversion device 20 receives reverse flow detection information from the system control circuit 15 via the communication line 42.
  • the communication line 42 is often installed over the DC bus 40 that connects the first power conversion device 10 and the second power conversion device 20, and in this configuration, the communication line 42 is affected by noise from the DC bus 40. .
  • the shorter the unit period representing one bit the weaker it becomes to noise. Basically, the bit error is more likely to occur as the communication speed is increased.
  • the first power conversion device 10 detects reverse power flow, generates communication data instructing output suppression, and transmits the communication data to the second power conversion device 20 via the communication line 42, it is defined in the grid interconnection regulations.
  • the time limit 500 ms
  • the content of communication data may change during the process due to noise.
  • the inverter control circuit 14 controls the inverter 13 so that the voltage of the DC bus 40 maintains the first threshold voltage as basic control.
  • the inverter control circuit 14 executes output suppression control as priority control. Specifically, the inverter control circuit 14 controls the inverter 13 so that the output of the inverter 13 does not exceed the command value (specifically, the upper limit current value or the upper limit power value) generated by the command value generation unit 15b.
  • the bus voltage stabilization control for controlling the voltage of the DC bus 40 to be maintained at the first threshold voltage is stopped.
  • the converter control circuit 22 receives, as basic control, the amount of discharge from the power storage unit 3 to the DC-DC converter 21 or the amount of charge from the DC-DC converter 21 to the power storage unit 3 transmitted from the system control circuit 15.
  • the DC-DC converter 21 is controlled so that the command value comes.
  • the converter control circuit 22 controls the DC-DC converter 21 as priority control so that the voltage of the DC bus 40 does not exceed the second threshold voltage. This control has priority over the control for adjusting the output to the command value transmitted from the system control circuit 15.
  • the second threshold voltage is set to a value higher than the first threshold voltage.
  • the converter control circuit 12 performs MPPT control on the DC-DC converter 11 so that the output power of the solar cell 2 is maximized as basic control. Further, the converter control circuit 12 controls the DC-DC converter 11 as priority control so that the voltage of the DC bus 40 does not exceed the third threshold voltage. This control has priority over MPPT control.
  • the third threshold voltage is set to a value higher than the second threshold voltage.
  • the first threshold voltage is set to a steady voltage of the DC bus 40.
  • the first threshold voltage is set in the range of DC 280 V to 360 V, for example.
  • the second threshold voltage is set to 390V
  • the third threshold voltage is set to 410V, for example.
  • FIG. 2 (a) and 2 (b) are diagrams schematically illustrating the voltage state of the DC bus 40.
  • FIG. FIG. 2A shows the voltage state of the DC bus 40 in a steady state. The constant voltage of the DC bus 40 is maintained at the first threshold voltage by the inverter 13.
  • FIG. 2B shows the voltage state of the DC bus 40 when the output of the inverter 13 is suppressed. Normally, the voltage of the DC bus 40 during output suppression is maintained at the second threshold voltage by the DC-DC converter 21 of the power storage unit 3.
  • the second power conversion device 20 When it is desired to suppress the initial investment in the power conversion system 1 shown in FIG. 1, the second power conversion device 20 is not connected and is operated in the state of the first power conversion device 10 alone (that is, the state of the photovoltaic power generation system). May start. Moreover, the 2nd power converter device 20 may be desired to be removed from the state of the power conversion system 1 shown in FIG. For example, when the power storage unit 3 is hardly used, the deterioration of the power storage unit 3 can be suppressed by removing the second power conversion device 20 from the DC bus 40.
  • FIG. 3A and 3B are diagrams illustrating an example of an output suppression reason when the second power conversion device 20 is in a disconnected state and an output suppression reason when the second power conversion device 20 is in a connected state. is there.
  • Fig.3 (a) when the 2nd power converter device 20 is a non-connection state, five types of output suppression reasons are prescribed
  • ⁇ Rated current excess is a restraining reason that occurs when the inverter 13 outputs a current exceeding the rated current of the inverter 13. For example, when the rated output current of the inverter 13 is 27.5A, the suppression reason occurs when the inverter 13 outputs a current exceeding 27.5A.
  • the rated power excess is a suppression reason that occurs when the inverter 13 outputs power exceeding the rated power of the inverter 13. For example, when the rated output power of the inverter 13 is 5.5 kW, when the inverter 13 outputs power exceeding 5.5 kW, the suppression reason occurs.
  • the rise in output voltage is a restraining reason that occurs when the output voltage of the inverter 13 exceeds a predetermined value.
  • the predetermined value is set to a value of 202 V or more in the case of three phases, and is set to a value of 107 V or more in the case of a single phase.
  • the remote output instruction is a control reason that occurs when it is received from a grid operating organization such as an electric power company via an external network. For example, an instruction such as “Please reduce the output power to OO kW from XX minutes to XX minutes in X minutes” is transmitted.
  • the high temperature abnormality is a suppression reason that occurs when the temperature in the first power conversion device 10 exceeds a predetermined value.
  • the predetermined value is set to 95 degrees.
  • the main heat source in the first power converter 10 is an inverter 13.
  • the output suppression control unit 15a of the first power converter 10 changes the output suppression amount of the inverter 13 according to the type of the output suppression reason. Specifically, the output suppression control unit 15a refers to the table shown in FIG. 3A to determine a limit value and a response time according to the type of output suppression reason.
  • the command value generation unit 15b generates a current command value / power command value for the inverter 13 according to the limit value and the response time determined by the output suppression control unit 15a.
  • the rated current excess and rated power excess are defined as the first priority
  • the output voltage rise is the second priority
  • the remote output instruction is the third priority
  • the high temperature abnormality is the fourth priority.
  • Higher priority output suppression reasons are more urgent and require faster responses.
  • the remote output instruction depends on the system operation period instruction, but is usually slower than the response when the output voltage rises. High temperature abnormalities are suppressed over a period of several minutes.
  • the limit value of the output current / output power of the inverter 13 changes due to multiple types of output suppression reasons.
  • the limit value of the output current of the inverter 13 becomes the rated current value.
  • a current value obtained by subtracting a margin from the rated current value may be used.
  • the limit value of the output power of the inverter 13 becomes the rated power value.
  • a power value obtained by subtracting a margin from the rated power value may be used.
  • the output current / output power of the inverter 13 is decreased at a prescribed response speed until the output voltage decreases to a target value (for example, 202V for three-phase, 107V for single-phase).
  • a target value for example, 202V for three-phase, 107V for single-phase.
  • the limit value of the output current / output power of the inverter 13 is a value specified by the grid operating engine.
  • the output current / output power of the inverter 13 is decreased at a prescribed response speed until the temperature in the first power converter 10 decreases to a target value (for example, 80 degrees).
  • the output suppression control unit 15a refers to the table shown in FIG. 3B and determines a limit value and a response time according to the type of the output suppression reason.
  • the reverse flow to the grid 4 is the first priority
  • the rated current excess is the second priority
  • the output voltage rise is the third priority
  • the remote output instruction is the priority 4th place
  • high temperature abnormality is defined as 5th priority.
  • the output current / output power limit value of the inverter 13 is a value at which the output power to the system 4 is 0 W or less, and the response time is less than 500 ms. This response time is the shortest response time among the response times of the output suppression reasons shown in FIG.
  • the output suppression control unit 15a outputs the output of the inverter 13 with the suppression amount and the response time for the highest priority output suppression reason when two or more types of output suppression reasons occur simultaneously among the multiple types of output suppression reasons. Suppress.
  • FIG. 4 is a diagram illustrating an example of the output of the inverter 13 when a plurality of types of output suppression reasons occur simultaneously.
  • the dotted line command value indicates the transition of the command value when the high temperature abnormality occurs
  • the solid line command value indicates the transition of the command value when the reverse power flow occurs.
  • the output suppression control unit 15a selects a lower command value at each time point.
  • the actual output power of the inverter 13 is the output power based on the command value at the time of occurrence of the high temperature abnormality from the occurrence of the high temperature abnormality to the occurrence of the reverse power flow, and becomes the output power based on the command value at the time of reverse power flow occurrence after the reverse power flow occurs.
  • the output suppression control is performed according to the system configuration by adding or eliminating the reverse power flow to the grid 4 for the output suppression reason. Can be optimized.
  • the inverter control circuit 14 and the system control circuit 15 are depicted separately, but each may be realized by a separate microcomputer or may be realized by a single microcomputer.
  • the example in which the first power conversion device 10 and the second power conversion device 20 are installed in different cases has been described.
  • a configuration example in which the system control circuit 15 and the converter control circuit 22 are connected by the communication line 42 while the first power conversion device 10 and the second power conversion device 20 are installed in one housing is also an example of the present invention. It is included in the embodiment.
  • the solar cell 2 is connected to the first power conversion device 10 .
  • another power generation device using renewable energy such as a wind power generation device or a micro hydraulic power generation device, may be connected.
  • a first DC-DC converter (11) for converting the voltage of the DC power output from the power generator (2) that generates power based on renewable energy, and outputting the converted DC power to the DC bus (40); Connected to the first DC-DC converter (11) via the DC bus (40), converts the DC power of the DC bus (40) into AC power, and converts the converted AC power into a load (5) or a power system
  • a control circuit (14, 15) for controlling the inverter (13), The said control circuit (14,15) changes the amount of suppression of the output of the said inverter (13) according to the classification of the output suppression reason of this power converter device (10),
  • the power converter device (10) characterized by the above-mentioned.
  • the control circuit (14, 15) suppresses an output suppression reason with the highest priority when two or more types of output suppression reasons occur among a plurality of types of output suppression reasons of the power conversion device (10).
  • a second DC-DC converter (21) for controlling input / output of the power storage unit (3) is connectable to the DC bus (40); In the state where the second DC-DC converter (21) is connected to the DC bus (40), the reverse flow to the power system (4) is included with the highest priority in the multiple types of output suppression reasons. When the second DC-DC converter (21) is not connected to the DC bus (40), the plurality of types of output suppression reasons do not include reverse power flow to the power system (4).
  • the power conversion device (10) according to item 1 or 2 According to this, an output suppression reason can be optimized according to whether or not the second DC-DC converter (21) is connected to the DC bus (40).
  • the control circuit (14, 15) suppresses the output of the inverter (13) at the fastest response speed among the plurality of types of output suppression reasons when a reverse power flow to the system 4 occurs.
  • Item 4. The power conversion device (10) according to item 3. According to this, the grid connection regulations can be satisfied.
  • the multiple types of output suppression reasons include an increase exceeding the rated power of the inverter output power, an increase exceeding the rated current of the inverter output current, an increase exceeding the predetermined value of the inverter output voltage, reception of a remote output command, and An increase exceeding a predetermined value of the temperature in the power converter (10) is included, and among these, an increase exceeding the rated power of the inverter output power and an increase exceeding the rated current of the inverter output current are priorities.
  • the power converter device (10) according to any one of items 1 to 4, characterized in that: According to this, suppression control according to the priority of each output suppression reason is attained, and the responsiveness with respect to each output suppression reason can be ensured.
  • a power conversion system (1) comprising a first power conversion device (10) and a second power conversion device (20),
  • the first power converter (10) A first DC-DC converter (11) for converting the voltage of the DC power output from the power generator (2) that generates power based on renewable energy, and outputting the converted DC power to the DC bus (40);
  • Connected to the first DC-DC converter (11) via the DC bus (40) converts the DC power of the DC bus (40) into AC power, and converts the converted AC power into a load (5) or a power system
  • a first control circuit (14, 15) for controlling the inverter (13),
  • the second power converter (20) A second DC-DC converter (21) for controlling input / output of the power storage unit (3);
  • the first control circuit (14, 15) changes an output suppression amount of the inverter (13) according to a type of an output suppression reason of the first power converter (10
  • the present invention can be used for a distributed power supply system in which a solar battery and a stationary storage battery are combined.

Abstract

In the present invention, a DC-DC converter 11 converts the voltage of DC power output from a power generation device that generates power on the basis of renewable energy, and the DC-DC converter outputs the converted DC power to a DC bus 40. An inverter 13 is connected to the DC-DC converter 11 via the DC bus 40, converts the DC power of the DC bus 40 to AC power, and supplies the converted AC power to a load 5 or a power system 4. Control circuits 14, 15 change the amount of suppression of the output of the inverter 13 according to the type of the reason for output-suppression carried out in this power conversion device 10.

Description

電力変換装置、電力変換システムPower conversion device, power conversion system
　本発明は、直流電力を交流電力に変換する電力変換装置、電力変換システムに関する。 The present invention relates to a power conversion device and a power conversion system that convert DC power into AC power.
　現在、系統連系される分散型電源には、電源ソースとして太陽電池、燃料電池、定置型蓄電池、車載蓄電池などがある。系統に連系する分散型電源システムの代表的な構成として、単一の分散型電源を使用してＤＣ－ＤＣコンバータ、直流バス及びインバータを介して系統連系する構成と、複数の分散型電源を使用してそれぞれのＤＣ－ＤＣコンバータ、共通の直流バス及び１つのインバータを介して系統連系する構成がある（例えば、特許文献１参照）。 Currently, distributed power sources that are grid-connected include solar cells, fuel cells, stationary storage batteries, and in-vehicle storage batteries as power sources. A typical configuration of a distributed power supply system connected to a system is a configuration in which a single distributed power supply is used to connect the system via a DC-DC converter, a DC bus and an inverter, and a plurality of distributed power supplies. Are connected to each other via each DC-DC converter, a common DC bus, and one inverter (see, for example, Patent Document 1).
　後者において、複数のＤＣ－ＤＣコンバータと１つのインバータが１つの筐体内に設置される構成と、少なくとも１つのＤＣ－ＤＣコンバータと１つのインバータが分離された筐体内に設置される構成がある。 In the latter, there are a configuration in which a plurality of DC-DC converters and one inverter are installed in one casing, and a configuration in which at least one DC-DC converter and one inverter are installed in a separate casing.
　また、物理的に１つの筐体内にＤＣ－ＤＣコンバータとインバータが設置される構成であっても、制御的にはＤＣ－ＤＣコンバータとインバータが別々の制御装置(例えば、マイコン)により独立に制御されることもある。このようなＤＣ－ＤＣコンバータとインバータが物理的もしくは制御的に分離された分散型電源システムでは、インバータと各種分散型電源を自由に組み合わせることができる。 Even if the DC-DC converter and the inverter are physically installed in a single housing, the DC-DC converter and the inverter are controlled independently by separate control devices (for example, a microcomputer). Sometimes it is done. In such a distributed power supply system in which the DC-DC converter and the inverter are physically or controlly separated, the inverter and various distributed power supplies can be freely combined.
　このような分散型電源システムでは安定動作させるために、システムの入出力電力の平衡を保つように制御する必要がある。さらに、系統と接続するために系統連系規程を遵守するための抑制処理を行ったり、安全に動作させるために過電流や温度異常を発生させないための抑制処理を行う必要がある。 In order to operate stably in such a distributed power supply system, it is necessary to control the input / output power of the system to be balanced. Furthermore, it is necessary to perform a suppression process for complying with the grid interconnection regulations in order to connect to the system, or to perform a suppression process for preventing overcurrent and temperature abnormality in order to operate safely.
特開２０１５－７３３６８号公報Japanese Patent Laying-Open No. 2015-73368
　一体型の分散型電源システムでは基本的に、１つの制御部で全ての情報を一括管理しており、状況に応じてシステムの入出力電力を調整する。各種の出力抑制事由に応じた抑制指示に対し、入力側および／または出力側で適応的な抑制制御を行い、システム全体の電力平衡が保たれるように制御される。 Integral distributed power supply system basically manages all information in a single control unit and adjusts the input / output power of the system according to the situation. In response to suppression instructions according to various output suppression reasons, adaptive suppression control is performed on the input side and / or output side, and control is performed so that power balance of the entire system is maintained.
　分離型の分散型電源システムでは各制御部が分離しており、システムの入出力電力の調整を一括制御することが難しい。各種の出力抑制事由に応じた抑制指示に対し、適切な抑制制御が行われないと、システム全体の電力平衡が崩れてしまう。 分離 In a separate distributed power supply system, each control unit is separated, and it is difficult to collectively control the input / output power of the system. If appropriate suppression control is not performed in response to suppression instructions corresponding to various output suppression reasons, the power balance of the entire system is lost.
　本発明はこうした状況に鑑みなされたものであり、その目的は、各種の出力抑制事由の発生に対して、的確な出力抑制制御を行うことができる電力変換装置、電力変換システムを提供することにある。 This invention is made | formed in view of such a condition, The objective is to provide the power converter device and power conversion system which can perform exact output suppression control with respect to generation | occurrence | production of various output suppression reasons. is there.
　上記課題を解決するために、本発明のある態様の電力変換装置は、再生可能エネルギーをもとに発電する発電装置の出力する直流電力の電圧を変換し、変換した直流電力を直流バスに出力する第１ＤＣ－ＤＣコンバータと、前記第１ＤＣ－ＤＣコンバータと前記直流バスを介して接続され、前記直流バスの直流電力を交流電力に変換し、変換した交流電力を負荷または電力系統に供給するインバータと、前記インバータを制御する制御回路と、を備える。前記制御回路は、本電力変換装置の出力抑制事由の種別に応じて、前記インバータの出力の抑制量を変える。 In order to solve the above problems, a power converter according to an aspect of the present invention converts a voltage of DC power output from a power generator that generates power based on renewable energy, and outputs the converted DC power to a DC bus. A first DC-DC converter, an inverter connected to the first DC-DC converter via the DC bus, converting DC power of the DC bus into AC power, and supplying the converted AC power to a load or a power system And a control circuit for controlling the inverter. The said control circuit changes the amount of suppression of the output of the said inverter according to the classification of the output suppression reason of this power converter device.
　本発明によれば、各種の出力抑制事由の発生に対して、的確な出力抑制制御を行うことができる。 According to the present invention, accurate output suppression control can be performed against the occurrence of various output suppression reasons.
本発明の実施の形態に係る電力変換システムを説明するための図である。It is a figure for demonstrating the power conversion system which concerns on embodiment of this invention. 図２（ａ）、（ｂ）は、直流バスの電圧の状態を模式的に描いた図である。2A and 2B are diagrams schematically illustrating the state of the voltage of the DC bus. 図３（ａ）、（ｂ）は、第２電力変換装置が非接続状態のときの出力抑制事由と、第２電力変換装置が接続状態のときの出力抑制事由の一例を示す図である。Drawing 3 (a) and (b) is a figure showing an example of an output control reason when the 2nd power converter is in a disconnection state, and an output control reason when the 2nd power converter is in a connection state. 複数種別の出力抑制事由が同時に発生した場合におけるインバータの出力の一例を示す図である。It is a figure which shows an example of the output of an inverter in case multiple types of output suppression reasons generate | occur | produce simultaneously.
　図１は、本発明の実施の形態に係る電力変換システム１を説明するための図である。電力変換システム１は、第１電力変換装置１０及び第２電力変換装置２０を備える。第１電力変換装置１０は太陽電池２用のパワーコンディショナシステムであり、第２電力変換装置２０は蓄電部３用のパワーコンディショナシステムである。図１では、太陽電池２用のパワーコンディショナシステムに、蓄電部３用のパワーコンディショナシステムを後付けした例を示している。 FIG. 1 is a diagram for explaining a power conversion system 1 according to an embodiment of the present invention. The power conversion system 1 includes a first power conversion device 10 and a second power conversion device 20. The first power conversion device 10 is a power conditioner system for the solar cell 2, and the second power conversion device 20 is a power conditioner system for the power storage unit 3. In FIG. 1, the example which retrofitted the power conditioner system for the electrical storage part 3 to the power conditioner system for the solar cells 2 is shown.
　太陽電池２は、光起電力効果を利用し、光エネルギーを直接電力に変換する発電装置である。太陽電池２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、色素増感型（有機太陽電池）等が使用される。太陽電池２は第１電力変換装置１０と接続され、発電した電力を第１電力変換装置１０に出力する。 The solar cell 2 is a power generation device that directly converts light energy into electric power using the photovoltaic effect. As the solar cell 2, a silicon solar cell, a solar cell made of a compound semiconductor or the like, a dye-sensitized type (organic solar cell), or the like is used. The solar cell 2 is connected to the first power conversion device 10 and outputs the generated power to the first power conversion device 10.
　第１電力変換装置１０は、ＤＣ－ＤＣコンバータ１１、コンバータ制御回路１２、インバータ１３、温度センサＴ１、インバータ制御回路１４、及びシステム制御回路１５を備える。システム制御回路１５は、出力抑制制御部１５ａ及び指令値生成部１５ｂを含む。ＤＣ－ＤＣコンバータ１１とインバータ１３間は直流バス４０で接続される。コンバータ制御回路１２とシステム制御回路１５間は通信線４１で接続され、両者の間で所定のシリアル通信規格（例えば、例えばＲＳ－４８５規格、ＴＣＰ－ＩＰ規格）に準拠した通信が行われる。 The first power converter 10 includes a DC-DC converter 11, a converter control circuit 12, an inverter 13, a temperature sensor T1, an inverter control circuit 14, and a system control circuit 15. The system control circuit 15 includes an output suppression control unit 15a and a command value generation unit 15b. The DC-DC converter 11 and the inverter 13 are connected by a DC bus 40. The converter control circuit 12 and the system control circuit 15 are connected by a communication line 41, and communication conforming to a predetermined serial communication standard (for example, RS-485 standard, TCP-IP standard) is performed between the two.
　ＤＣ－ＤＣコンバータ１１は、太陽電池２から出力される直流電力を、所望の電圧値の直流電力に変換し、変換した直流電力を直流バス４０に出力する。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 DC-DC converter 11 converts the DC power output from the solar cell 2 into DC power having a desired voltage value, and outputs the converted DC power to the DC bus 40. The DC-DC converter 11 can be constituted by a step-up chopper, for example.
　コンバータ制御回路１２はＤＣ－ＤＣコンバータ１１を制御する。コンバータ制御回路１２は基本制御として、太陽電池２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１２は、太陽電池２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計測して太陽電池２の発電電力を推定する。コンバータ制御回路１２は、計測した太陽電池２の出力電圧と推定した発電電力をもとに、太陽電池２の発電電力を最大電力点（最適動作点）にするための指令値を生成する。例えば、山登り法に従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指令値を生成する。ＤＣ－ＤＣコンバータ１１は、生成された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 12 controls the DC-DC converter 11. As a basic control, the converter control circuit 12 performs MPPT (Maximum Power Point Tracking) control of the DC-DC converter 11 so that the output power of the solar cell 2 is maximized. Specifically, converter control circuit 12 measures the input voltage and input current of DC-DC converter 11, which are the output voltage and output current of solar cell 2, and estimates the generated power of solar cell 2. The converter control circuit 12 generates a command value for setting the generated power of the solar battery 2 to the maximum power point (optimum operating point) based on the measured output voltage of the solar battery 2 and the estimated generated power. For example, the maximum power point is searched by changing the operating point voltage with a predetermined step width according to the hill-climbing method, and the command value is generated so as to maintain the maximum power point. The DC-DC converter 11 performs a switching operation according to a drive signal based on the generated command value.
　インバータ１３は双方向インバータであり、直流バス４０から入力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商用電力系統（以下、単に系統４という）に接続された配電線５０に出力する。当該配電線５０には負荷５が接続される。またインバータ１３は、系統４から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４０に出力する。直流バス４０には、平滑用の電解コンデンサ（不図示）が接続されている。 The inverter 13 is a bidirectional inverter that converts DC power input from the DC bus 40 into AC power and outputs the converted AC power to a distribution line 50 connected to a commercial power system (hereinafter simply referred to as system 4). To do. A load 5 is connected to the distribution line 50. Further, the inverter 13 converts AC power supplied from the system 4 into DC power, and outputs the converted DC power to the DC bus 40. A smoothing electrolytic capacitor (not shown) is connected to the DC bus 40.
　インバータ制御回路１４はインバータ１３を制御する。インバータ制御回路１４は基本制御として、直流バス４０の電圧が第１閾値電圧を維持するようにインバータ１３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４０の電圧を検出し、検出したバス電圧を第１閾値電圧に一致させるための指令値を生成する。インバータ制御回路１４は、直流バス４０の電圧が第１閾値電圧より高い場合はインバータ１３のデューティ比を上げるための指令値を生成し、直流バス４０の電圧が第１閾値電圧より低い場合はインバータ１３のデューティ比を下げるための指令値を生成する。インバータ１３は、生成された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 13. As a basic control, the inverter control circuit 14 controls the inverter 13 so that the voltage of the DC bus 40 maintains the first threshold voltage. Specifically, the inverter control circuit 14 detects the voltage of the DC bus 40 and generates a command value for making the detected bus voltage coincide with the first threshold voltage. The inverter control circuit 14 generates a command value for increasing the duty ratio of the inverter 13 when the voltage of the DC bus 40 is higher than the first threshold voltage, and the inverter control circuit 14 when the voltage of the DC bus 40 is lower than the first threshold voltage. A command value for lowering the duty ratio of 13 is generated. The inverter 13 performs a switching operation according to a drive signal based on the generated command value.
　温度センサＴ１は、第１電力変換装置１０内の温度を検出して、システム制御回路１５に出力する。温度センサＴ１には例えば、サーミスタ、熱電対などを使用することができる。 The temperature sensor T1 detects the temperature in the first power converter 10 and outputs it to the system control circuit 15. For example, a thermistor, a thermocouple, or the like can be used as the temperature sensor T1.
　蓄電部３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、電気二重層キャパシタ、リチウムイオンキャパシタ等を含む。蓄電部３は第２電力変換装置２０と接続される。 The power storage unit 3 can charge and discharge electric power, and includes a lithium ion storage battery, a nickel hydride storage battery, a lead storage battery, an electric double layer capacitor, a lithium ion capacitor, and the like. The power storage unit 3 is connected to the second power conversion device 20.
　第２電力変換装置２０は、ＤＣ－ＤＣコンバータ２１及びコンバータ制御回路２２を備える。コンバータ制御回路２２と、第１電力変換装置１０のシステム制御回路１５は通信線４２で接続され、両者の間で所定のシリアル通信規格に準拠した通信が行われる。 The second power conversion device 20 includes a DC-DC converter 21 and a converter control circuit 22. The converter control circuit 22 and the system control circuit 15 of the first power conversion device 10 are connected by a communication line 42, and communication based on a predetermined serial communication standard is performed between them.
　ＤＣ－ＤＣコンバータ２１は、蓄電部３と直流バス４０の間に接続され、蓄電部３を充放電する双方向コンバータである。コンバータ制御回路２２はＤＣ－ＤＣコンバータ２１を制御する。コンバータ制御回路２２は基本制御として、システム制御回路１５から送信されてくる指令値をもとにＤＣ－ＤＣコンバータ２１を制御して、蓄電部３を定電流（ＣＣ）／定電圧（ＣＶ）で充電／放電する。例えばコンバータ制御回路２２は、放電時においてシステム制御回路１５から電力指令値を受信し、当該電力指令値を蓄電部３の電圧で割った値を電流指令値として、ＤＣ－ＤＣコンバータ２１に定電流放電させる。 The DC-DC converter 21 is a bidirectional converter that is connected between the power storage unit 3 and the DC bus 40 and charges and discharges the power storage unit 3. The converter control circuit 22 controls the DC-DC converter 21. As a basic control, the converter control circuit 22 controls the DC-DC converter 21 based on the command value transmitted from the system control circuit 15 to control the power storage unit 3 at a constant current (CC) / constant voltage (CV). Charge / discharge. For example, the converter control circuit 22 receives a power command value from the system control circuit 15 at the time of discharging, and uses a value obtained by dividing the power command value by the voltage of the power storage unit 3 as a current command value. Discharge.
　蓄電部３からの放電中に、日射変動により太陽電池２の発電量が増加した場合、又は負荷５の消費電力が低下した場合、系統４への逆潮流電力が発生し、売電状態になることがある。日本では系統連系規程により蓄電システムから、蓄電池の定格容量の５％以上の電力を５００ｍｓを超えて系統４へ逆潮流することが禁止されている。従って、蓄電部３が接続された電力変換システム１において逆潮流が検出された場合、５００ｍｓ以内に逆潮流を抑える必要がある。 When the amount of power generated by the solar cell 2 increases due to fluctuations in solar radiation or when the power consumption of the load 5 decreases during discharge from the power storage unit 3, reverse power flow to the grid 4 is generated and the power is sold. Sometimes. In Japan, the grid connection regulations prohibit the reverse flow of power from the power storage system to the grid 4 for more than 5% of the rated capacity of the storage battery over 500 ms. Therefore, when a reverse power flow is detected in the power conversion system 1 to which the power storage unit 3 is connected, it is necessary to suppress the reverse power flow within 500 ms.
　また日本では２０１５年１月の再生可能エネルギー固定価格買取制度の改正により、新たに系統に連系する太陽光発電と風力発電の設備に遠隔出力制御システムの導入が義務付けられている。システム制御回路１５は、電力会社などの系統運用機関から外部ネットワーク（例えば、インターネット又は専用線）を介して、系統４への出力電力量と出力タイミングに関する指示を受信する。 In Japan, the revision of the renewable energy feed-in tariff system in January 2015 has made it mandatory to introduce a remote output control system for solar and wind power generation facilities that are newly connected to the grid. The system control circuit 15 receives an instruction related to the output power amount and output timing to the grid 4 from a grid operating organization such as a power company via an external network (for example, the Internet or a dedicated line).
　インバータ１３の出力電力を抑制する方法として、太陽電池２のＤＣ－ＤＣコンバータ１１の出力電力を抑制する方法、蓄電部３のＤＣ－ＤＣコンバータ２１の出力電力を抑制する方法、インバータ１３の出力電力を抑制する方法がある。太陽電池２のＤＣ－ＤＣコンバータ１１の出力電力を抑制する方法は、太陽電池２の発電量を無駄にすることに繋がる。従って太陽電池２のＤＣ－ＤＣコンバータ１１の出力抑制は最後に実行すべき制御である。 As a method of suppressing the output power of the inverter 13, a method of suppressing the output power of the DC-DC converter 11 of the solar cell 2, a method of suppressing the output power of the DC-DC converter 21 of the power storage unit 3, and the output power of the inverter 13 There is a way to suppress this. The method of suppressing the output power of the DC-DC converter 11 of the solar cell 2 leads to wasted power generation amount of the solar cell 2. Therefore, the output suppression of the DC-DC converter 11 of the solar cell 2 is the control to be executed last.
　逆潮流が検出された場合、蓄電部３からの放電を停止すればよいため、蓄電部３のＤＣ－ＤＣコンバータ２１の出力電力を抑制する方法が最も直截的な制御である。しかしながら、第２電力変換装置２０が第１電力変換装置１０から分離され、系統４から離れた位置に設置されている場合、逆潮流の検出から蓄電部３のＤＣ－ＤＣコンバータ２１の出力抑制までにタイムラグが発生しやすくなる。 When the reverse power flow is detected, it is only necessary to stop the discharge from the power storage unit 3, so the method for suppressing the output power of the DC-DC converter 21 of the power storage unit 3 is the most straightforward control. However, when the second power conversion device 20 is separated from the first power conversion device 10 and installed at a position away from the grid 4, from detection of reverse power flow to output suppression of the DC-DC converter 21 of the power storage unit 3. Time lag is likely to occur.
　図１に示した構成では、第１電力変換装置１０のシステム制御回路１５が、配電線５０の、分電盤より系統４側に設置されたＣＴセンサ（不図示）の計測値をもとに逆潮流電力を検出する。第２電力変換装置２０のコンバータ制御回路２２は、システム制御回路１５から通信線４２を介して逆潮流の検出情報を受信する。通信線４２は、第１電力変換装置１０と第２電力変換装置２０を繋ぐ直流バス４０に這わせて設置されることが多く、この構成では通信線４２は直流バス４０からノイズの影響を受ける。また二値の電圧を使用したデジタル通信では、１ビットを表す単位期間を短くするほどノイズに弱くなる性質があり、基本的に通信速度を上げるほどビット誤りが発生しやすくなる。 In the configuration shown in FIG. 1, the system control circuit 15 of the first power converter 10 is based on the measured value of a CT sensor (not shown) installed on the system 4 side of the distribution line 50 from the distribution board. Detect reverse power flow. The converter control circuit 22 of the second power conversion device 20 receives reverse flow detection information from the system control circuit 15 via the communication line 42. The communication line 42 is often installed over the DC bus 40 that connects the first power conversion device 10 and the second power conversion device 20, and in this configuration, the communication line 42 is affected by noise from the DC bus 40. . In digital communication using a binary voltage, the shorter the unit period representing one bit, the weaker it becomes to noise. Basically, the bit error is more likely to occur as the communication speed is increased.
　従って第１電力変換装置１０が逆潮流を検出し、出力抑制を指示する通信データを生成し、通信線４２を介して第２電力変換装置２０に送信する方法では、系統連系規程に定められる時限（５００ｍｓ）を遵守できない可能性がある。またノイズにより通信データの内容が途中で変わってしまう可能性もある。 Therefore, in the method in which the first power conversion device 10 detects reverse power flow, generates communication data instructing output suppression, and transmits the communication data to the second power conversion device 20 via the communication line 42, it is defined in the grid interconnection regulations. There is a possibility that the time limit (500 ms) cannot be observed. In addition, the content of communication data may change during the process due to noise.
　そこで先にインバータ１３の出力電力を抑制し、後から蓄電部３のＤＣ－ＤＣコンバータ２１の出力電力を抑制する方法が考えられる。上述のようにインバータ制御回路１４は基本制御として、直流バス４０の電圧が第１閾値電圧を維持するようにインバータ１３を制御する。出力抑制をすべき場合は、インバータ制御回路１４は優先制御として、出力抑制制御を実行する。具体的にはインバータ制御回路１４は、インバータ１３の出力が指令値生成部１５ｂにより生成された指令値（具体的には上限電流値または上限電力値）を超えないようにインバータ１３を制御する。出力抑制中は、直流バス４０の電圧を第１閾値電圧に維持するように制御するバス電圧の安定化制御は停止する。 Therefore, a method is conceivable in which the output power of the inverter 13 is first suppressed and the output power of the DC-DC converter 21 of the power storage unit 3 is subsequently suppressed. As described above, the inverter control circuit 14 controls the inverter 13 so that the voltage of the DC bus 40 maintains the first threshold voltage as basic control. When output suppression is to be performed, the inverter control circuit 14 executes output suppression control as priority control. Specifically, the inverter control circuit 14 controls the inverter 13 so that the output of the inverter 13 does not exceed the command value (specifically, the upper limit current value or the upper limit power value) generated by the command value generation unit 15b. During the output suppression, the bus voltage stabilization control for controlling the voltage of the DC bus 40 to be maintained at the first threshold voltage is stopped.
　インバータ１３の出力抑制が開始した時点では、太陽電池２のＤＣ－ＤＣコンバータ１１及び／又は蓄電部３のＤＣ－ＤＣコンバータ２１の出力抑制は開始していない。従ってインバータ１３の出力電力に対してインバータ１３の入力電力が過多となり、直流バス４０の電圧が上昇する。より具体的には直流バス４０に接続された電解コンデンサに電荷が蓄積されていく。 At the time when output suppression of the inverter 13 is started, output suppression of the DC-DC converter 11 of the solar cell 2 and / or the DC-DC converter 21 of the power storage unit 3 is not started. Therefore, the input power of the inverter 13 becomes excessive with respect to the output power of the inverter 13, and the voltage of the DC bus 40 increases. More specifically, electric charges are accumulated in the electrolytic capacitor connected to the DC bus 40.
　上述のようにコンバータ制御回路２２は基本制御として、蓄電部３からＤＣ－ＤＣコンバータ２１への放電量またはＤＣ－ＤＣコンバータ２１から蓄電部３への充電量が、システム制御回路１５から送信されてくる指令値になるようにＤＣ－ＤＣコンバータ２１を制御する。さらにコンバータ制御回路２２は優先制御として、直流バス４０の電圧が第２閾値電圧を超えないようにＤＣ－ＤＣコンバータ２１を制御する。この制御は、システム制御回路１５から送信されてくる指令値に出力を合わせる制御に対して優先する。第２閾値電圧は第１閾値電圧より高い値に設定される。 As described above, the converter control circuit 22 receives, as basic control, the amount of discharge from the power storage unit 3 to the DC-DC converter 21 or the amount of charge from the DC-DC converter 21 to the power storage unit 3 transmitted from the system control circuit 15. The DC-DC converter 21 is controlled so that the command value comes. Furthermore, the converter control circuit 22 controls the DC-DC converter 21 as priority control so that the voltage of the DC bus 40 does not exceed the second threshold voltage. This control has priority over the control for adjusting the output to the command value transmitted from the system control circuit 15. The second threshold voltage is set to a value higher than the first threshold voltage.
　上述のようにコンバータ制御回路１２は基本制御として、太陽電池２の出力電力が最大になるようＤＣ－ＤＣコンバータ１１をＭＰＰＴ制御する。さらにコンバータ制御回路１２は優先制御として、直流バス４０の電圧が第３閾値電圧を超えないようにＤＣ－ＤＣコンバータ１１を制御する。この制御は、ＭＰＰＴ制御に対して優先する。第３閾値電圧は第２閾値電圧より高い値に設定される。 As described above, the converter control circuit 12 performs MPPT control on the DC-DC converter 11 so that the output power of the solar cell 2 is maximized as basic control. Further, the converter control circuit 12 controls the DC-DC converter 11 as priority control so that the voltage of the DC bus 40 does not exceed the third threshold voltage. This control has priority over MPPT control. The third threshold voltage is set to a value higher than the second threshold voltage.
　第１閾値電圧は、直流バス４０の定常時の電圧に設定される。系統電圧がＡＣ２００Ｖの場合、第１閾値電圧は例えば、ＤＣ２８０Ｖ～３６０Ｖの範囲に設定される。第２閾値電圧は例えば３９０Ｖ、第３閾値電圧は例えば４１０Ｖに設定される。インバータ１３の出力抑制により直流バス４０の電圧が上昇し、直流バス４０の電圧が第２閾値電圧に到達すると蓄電部３のＤＣ－ＤＣコンバータ２１によるバス電圧の上昇抑制制御が発動する。直流バス４０の電圧上昇のエネルギーが、蓄電部３のＤＣ－ＤＣコンバータ２１による上昇抑制エネルギーより大きい場合は、直流バス４０の電圧がさらに上昇する。直流バス４０の電圧が第３閾値電圧に到達すると太陽電池２のＤＣ－ＤＣコンバータ１１によるバス電圧の上昇抑制制御が発動する。 The first threshold voltage is set to a steady voltage of the DC bus 40. When the system voltage is 200 V AC, the first threshold voltage is set in the range of DC 280 V to 360 V, for example. For example, the second threshold voltage is set to 390V, and the third threshold voltage is set to 410V, for example. When the output of the inverter 13 is suppressed, the voltage of the DC bus 40 increases, and when the voltage of the DC bus 40 reaches the second threshold voltage, the bus voltage increase suppression control by the DC-DC converter 21 of the power storage unit 3 is activated. When the energy for increasing the voltage of the DC bus 40 is larger than the energy for suppressing the increase by the DC-DC converter 21 of the power storage unit 3, the voltage of the DC bus 40 further increases. When the voltage of the DC bus 40 reaches the third threshold voltage, the bus voltage rise suppression control by the DC-DC converter 11 of the solar cell 2 is activated.
　図２（ａ）、（ｂ）は、直流バス４０の電圧の状態を模式的に描いた図である。図２（ａ）は、定常時の直流バス４０の電圧の状態を示している。定常時の直流バス４０の電圧は、インバータ１３により第１閾値電圧に維持される。図２（ｂ）は、インバータ１３の出力抑制時の直流バス４０の電圧の状態を示している。通常、出力抑制中の直流バス４０の電圧は、蓄電部３のＤＣ－ＤＣコンバータ２１により第２閾値電圧に維持される。 2 (a) and 2 (b) are diagrams schematically illustrating the voltage state of the DC bus 40. FIG. FIG. 2A shows the voltage state of the DC bus 40 in a steady state. The constant voltage of the DC bus 40 is maintained at the first threshold voltage by the inverter 13. FIG. 2B shows the voltage state of the DC bus 40 when the output of the inverter 13 is suppressed. Normally, the voltage of the DC bus 40 during output suppression is maintained at the second threshold voltage by the DC-DC converter 21 of the power storage unit 3.
　図１に示した電力変換システム１において初期投資を抑えたい場合、第２電力変換装置２０が接続されずに第１電力変換装置１０単体の状態（即ち、太陽光発電システムの状態）で運用を開始することがある。また図１に示した電力変換システム１の状態から、第２電力変換装置２０を取り外したい場合がある。例えば、蓄電部３を殆ど使用していない場合、第２電力変換装置２０を直流バス４０から取り外しておいた方が蓄電部３の劣化を抑えることができる。 When it is desired to suppress the initial investment in the power conversion system 1 shown in FIG. 1, the second power conversion device 20 is not connected and is operated in the state of the first power conversion device 10 alone (that is, the state of the photovoltaic power generation system). May start. Moreover, the 2nd power converter device 20 may be desired to be removed from the state of the power conversion system 1 shown in FIG. For example, when the power storage unit 3 is hardly used, the deterioration of the power storage unit 3 can be suppressed by removing the second power conversion device 20 from the DC bus 40.
　図３（ａ）、（ｂ）は、第２電力変換装置２０が非接続状態のときの出力抑制事由と、第２電力変換装置２０が接続状態のときの出力抑制事由の一例を示す図である。図３（ａ）に示すように、第２電力変換装置２０が非接続状態のときは５種類の出力抑制事由が規定されている。 3A and 3B are diagrams illustrating an example of an output suppression reason when the second power conversion device 20 is in a disconnected state and an output suppression reason when the second power conversion device 20 is in a connected state. is there. As shown to Fig.3 (a), when the 2nd power converter device 20 is a non-connection state, five types of output suppression reasons are prescribed | regulated.
　定格電流超過は、インバータ１３の定格電流を超える電流をインバータ１３が出力したときに発生する抑制事由である。例えば、インバータ１３の定格出力電流が２７．５Ａの場合、インバータ１３が２７．５Ａを超える電流を出力すると当該抑制事由が発生する。定格電力超過は、インバータ１３の定格電力を超える電力をインバータ１３が出力したときに発生する抑制事由である。例えば、インバータ１３の定格出力電力が５．５ｋＷの場合、インバータ１３が５．５ｋＷを超える電力を出力すると当該抑制事由が発生する。 超過 Rated current excess is a restraining reason that occurs when the inverter 13 outputs a current exceeding the rated current of the inverter 13. For example, when the rated output current of the inverter 13 is 27.5A, the suppression reason occurs when the inverter 13 outputs a current exceeding 27.5A. The rated power excess is a suppression reason that occurs when the inverter 13 outputs power exceeding the rated power of the inverter 13. For example, when the rated output power of the inverter 13 is 5.5 kW, when the inverter 13 outputs power exceeding 5.5 kW, the suppression reason occurs.
　出力電圧上昇は、インバータ１３の出力電圧が所定値を超えたときに発生する抑制事由である。例えば所定値は、三相の場合は２０２Ｖ以上の値に設定され、単相の場合は１０７Ｖ以上の値に設定される。遠隔出力指示は、電力会社などの系統運用機関から外部ネットワークを介して受信した際に発生する抑制事由である。例えば、「ＸＸ時ＸＸ分からＸ分間で、出力電力を〇〇ｋＷまで低下してください。」といった指示が送信されてくる。 The rise in output voltage is a restraining reason that occurs when the output voltage of the inverter 13 exceeds a predetermined value. For example, the predetermined value is set to a value of 202 V or more in the case of three phases, and is set to a value of 107 V or more in the case of a single phase. The remote output instruction is a control reason that occurs when it is received from a grid operating organization such as an electric power company via an external network. For example, an instruction such as “Please reduce the output power to OO kW from XX minutes to XX minutes in X minutes” is transmitted.
　高温異常は、第１電力変換装置１０内の温度が所定値を超えたときに発生する抑制事由である。例えば所定値は、９５度に設定される。第１電力変換装置１０内の主な発熱源はインバータ１３である。 The high temperature abnormality is a suppression reason that occurs when the temperature in the first power conversion device 10 exceeds a predetermined value. For example, the predetermined value is set to 95 degrees. The main heat source in the first power converter 10 is an inverter 13.
　第１電力変換装置１０の出力抑制制御部１５ａは、出力抑制事由の種別に応じて、インバータ１３の出力の抑制量を変える。具体的には出力抑制制御部１５ａは、図３（ａ）に示したテーブルを参照して、出力抑制事由の種別に応じたリミット値と応答時間を決定する。指令値生成部１５ｂは、出力抑制制御部１５ａにより決定されたリミット値と応答時間に応じて、インバータ１３の電流指令値／電力指令値を生成する。 The output suppression control unit 15a of the first power converter 10 changes the output suppression amount of the inverter 13 according to the type of the output suppression reason. Specifically, the output suppression control unit 15a refers to the table shown in FIG. 3A to determine a limit value and a response time according to the type of output suppression reason. The command value generation unit 15b generates a current command value / power command value for the inverter 13 according to the limit value and the response time determined by the output suppression control unit 15a.
　図３（ａ）に示す例では、定格電流超過、定格電力超過が優先度１位、出力電圧上昇が優先度２位、遠隔出力指示が優先度３位、高温異常が優先度４位に規定されている。優先度が高い出力抑制事由の方が緊急性が高く、より速い応答が求められる。なお遠隔出力指示は系統運用期間の指示に依存するが、通常、出力電圧上昇時の応答より遅くなる。高温異常は、数分以上の時間をかけて抑制する。 In the example shown in FIG. 3A, the rated current excess and rated power excess are defined as the first priority, the output voltage rise is the second priority, the remote output instruction is the third priority, and the high temperature abnormality is the fourth priority. Has been. Higher priority output suppression reasons are more urgent and require faster responses. The remote output instruction depends on the system operation period instruction, but is usually slower than the response when the output voltage rises. High temperature abnormalities are suppressed over a period of several minutes.
　複数種別の出力抑制事由により、インバータ１３の出力電流／出力電力のリミット値が変わってくる。定格電流超過の場合、インバータ１３の出力電流のリミット値は定格電流値になる。なお、定格電流値からマージンを引いた電流値を使用してもよい。定格電力超過の場合、インバータ１３の出力電力のリミット値は定格電力値になる。なお、定格電力値からマージンを引いた電力値を使用してもよい。 リ ミ ッ ト The limit value of the output current / output power of the inverter 13 changes due to multiple types of output suppression reasons. When the rated current is exceeded, the limit value of the output current of the inverter 13 becomes the rated current value. A current value obtained by subtracting a margin from the rated current value may be used. When the rated power is exceeded, the limit value of the output power of the inverter 13 becomes the rated power value. A power value obtained by subtracting a margin from the rated power value may be used.
　出力電圧上昇の場合、出力電圧が目標値（例えば、三相の場合は２０２Ｖ、単相の場合１０７Ｖ）に低下するまで、インバータ１３の出力電流／出力電力を、規定された応答速度で低下させる。遠隔出力指示の場合、インバータ１３の出力電流／出力電力のリミット値は系統運用機関に指定された値になる。高温異常の場合、第１電力変換装置１０内の温度が目標値（例えば、８０度）に低下するまで、インバータ１３の出力電流／出力電力を、規定された応答速度で低下させる。 In the case of an increase in output voltage, the output current / output power of the inverter 13 is decreased at a prescribed response speed until the output voltage decreases to a target value (for example, 202V for three-phase, 107V for single-phase). . In the case of a remote output instruction, the limit value of the output current / output power of the inverter 13 is a value specified by the grid operating engine. In the case of a high temperature abnormality, the output current / output power of the inverter 13 is decreased at a prescribed response speed until the temperature in the first power converter 10 decreases to a target value (for example, 80 degrees).
　第１電力変換装置１０に第２電力変換装置２０が接続された状態では、出力抑制事由に、系統４への逆潮流が優先度１位で加わる。出力抑制制御部１５ａは、図３（ｂ）に示したテーブルを参照して、出力抑制事由の種別に応じたリミット値と応答時間を決定する。図３（ｂ）に示す例では、系統４への逆潮流が優先度１位、定格電流超過、定格電力超過が優先度２位、出力電圧上昇が優先度３位、遠隔出力指示が優先度４位、高温異常が優先度５位に規定されている。系統４への逆潮流では、インバータ１３の出力電流／出力電力のリミット値は、系統４への出力電力が０Ｗ以下になる値であり、応答時間は５００ｍｓ未満である。この応答時間は、図３（ｂ）に示される出力抑制事由の応答時間の内、最も短い応答時間である。 In the state where the second power conversion device 20 is connected to the first power conversion device 10, the reverse power flow to the system 4 is added at the first priority for the reason of output suppression. The output suppression control unit 15a refers to the table shown in FIG. 3B and determines a limit value and a response time according to the type of the output suppression reason. In the example shown in FIG. 3 (b), the reverse flow to the grid 4 is the first priority, the rated current excess, the rated power excess is the second priority, the output voltage rise is the third priority, and the remote output instruction is the priority 4th place, high temperature abnormality is defined as 5th priority. In the reverse power flow to the system 4, the output current / output power limit value of the inverter 13 is a value at which the output power to the system 4 is 0 W or less, and the response time is less than 500 ms. This response time is the shortest response time among the response times of the output suppression reasons shown in FIG.
　出力抑制制御部１５ａは、複数種別の出力抑制事由の内、２つの種別以上の出力抑制事由が同時に発生した場合、最も優先度の高い出力抑制事由に対する抑制量および応答時間でインバータ１３の出力を抑制する。 The output suppression control unit 15a outputs the output of the inverter 13 with the suppression amount and the response time for the highest priority output suppression reason when two or more types of output suppression reasons occur simultaneously among the multiple types of output suppression reasons. Suppress.
　図４は、複数種別の出力抑制事由が同時に発生した場合におけるインバータ１３の出力の一例を示す図である。点線の指令値は、高温異常発生時の指令値の推移を示し、実線の指令値は逆潮流発生時の指令値の推移を示している。出力抑制制御部１５ａは各時点において、より低い指令値を選択する。インバータ１３の実際の出力電力は、高温異常発生から逆潮流発生までは高温異常発生時の指令値に基づく出力電力となり、逆潮流発生後は逆潮流発生時の指令値に基づく出力電力となる。 FIG. 4 is a diagram illustrating an example of the output of the inverter 13 when a plurality of types of output suppression reasons occur simultaneously. The dotted line command value indicates the transition of the command value when the high temperature abnormality occurs, and the solid line command value indicates the transition of the command value when the reverse power flow occurs. The output suppression control unit 15a selects a lower command value at each time point. The actual output power of the inverter 13 is the output power based on the command value at the time of occurrence of the high temperature abnormality from the occurrence of the high temperature abnormality to the occurrence of the reverse power flow, and becomes the output power based on the command value at the time of reverse power flow occurrence after the reverse power flow occurs.
　以上説明したように本実施の形態によれば、出力抑制事由の種別に応じた抑制制御が可能になり、各出力抑制事由に対する応答性を確保することができる。従って、電力変換システム１全体の入出力の電力平衡を保つことができる。 As described above, according to this embodiment, it is possible to perform suppression control according to the type of output suppression reason, and it is possible to ensure responsiveness to each output suppression reason. Therefore, the input / output power balance of the entire power conversion system 1 can be maintained.
　また蓄電部３に接続された第２電力変換装置２０の接続の有無に応じて、出力抑制事由に、系統４への逆潮流を追加または排除することにより、システム構成に応じて出力抑制制御を最適化することができる。 In addition, depending on whether or not the second power conversion device 20 connected to the power storage unit 3 is connected, the output suppression control is performed according to the system configuration by adding or eliminating the reverse power flow to the grid 4 for the output suppression reason. Can be optimized.
　以上、本発明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発明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 invention has been described based on the embodiments. The embodiments are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are within the scope of the present invention. .
　図１では、インバータ制御回路１４とシステム制御回路１５を分離して描いているが、それぞれが別のマイクロコンピュータで実現されてもよいし、１つのマイクロコンピュータで実現されてもよい。また上述の実施の形態では、第１電力変換装置１０と第２電力変換装置２０が別の筐体に設置される例を説明した。この点、第１電力変換装置１０と第２電力変換装置２０が１つの筐体に設置されつつ、システム制御回路１５とコンバータ制御回路２２が通信線４２で接続される構成例も本発明の一実施の形態に含まれる。 In FIG. 1, the inverter control circuit 14 and the system control circuit 15 are depicted separately, but each may be realized by a separate microcomputer or may be realized by a single microcomputer. Moreover, in the above-described embodiment, the example in which the first power conversion device 10 and the second power conversion device 20 are installed in different cases has been described. In this regard, a configuration example in which the system control circuit 15 and the converter control circuit 22 are connected by the communication line 42 while the first power conversion device 10 and the second power conversion device 20 are installed in one housing is also an example of the present invention. It is included in the embodiment.
　また上記実施の形態では、第１電力変換装置１０に太陽電池２が接続される例を説明した。この点、太陽電池２の代わりに、風力発電装置、マイクロ水力発電装置など、再生可能エネルギーを用いた他の発電装置が接続されてもよい。 In the above embodiment, an example in which the solar cell 2 is connected to the first power conversion device 10 has been described. In this respect, instead of the solar battery 2, another power generation device using renewable energy, such as a wind power generation device or a micro hydraulic power generation device, may be connected.
　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。 Note that the embodiment may be specified by the following items.
［項目１］
　再生可能エネルギーをもとに発電する発電装置（２）の出力する直流電力の電圧を変換し、変換した直流電力を直流バス（４０）に出力する第１ＤＣ－ＤＣコンバータ（１１）と、
　前記第１ＤＣ－ＤＣコンバータ（１１）と前記直流バス（４０）を介して接続され、前記直流バス（４０）の直流電力を交流電力に変換し、変換した交流電力を負荷（５）または電力系統（４）に供給するインバータ（１３）と、
　前記インバータ（１３）を制御する制御回路（１４、１５）と、を備え、
　前記制御回路（１４、１５）は、本電力変換装置（１０）の出力抑制事由の種別に応じて、前記インバータ（１３）の出力の抑制量を変えることを特徴とする電力変換装置（１０）。
　これによれば、出力抑制事由の種別に応じた応答性を確保することができる。
［項目２］
　前記制御回路（１４、１５）は、本電力変換装置（１０）の複数種別の出力抑制事由の内、２つの種別以上の出力抑制事由が発生した場合、最も優先度の高い出力抑制事由に対する抑制量および応答時間で前記インバータ（１４）の出力を抑制することを特徴とする項目１に記載の電力変換装置（１０）。
　これによれば、複数種別の出力抑制事由が同時に発生しても、要求される出力抑制を実現することができる。
［項目３］
　蓄電部（３）の入出力を制御する第２ＤＣ－ＤＣコンバータ（２１）が、前記直流バス（４０）に接続可能な構成であり、
　前記第２ＤＣ－ＤＣコンバータ（２１）が前記直流バス（４０）に接続された状態では、前記複数種別の出力抑制事由に、前記電力系統（４）への逆潮流が最も高い優先度で含まれており、前記第２ＤＣ－ＤＣコンバータ（２１）が前記直流バス（４０）に非接続の状態では、前記複数種別の出力抑制事由に、前記電力系統（４）への逆潮流が含まれないことを特徴とする項目１または２に記載の電力変換装置（１０）。
　これによれば、第２ＤＣ－ＤＣコンバータ（２１）の直流バス（４０）への接続の有無に応じて、出力抑制事由を最適化することができる。
［項目４］
　前記制御回路（１４、１５）は、前記系統４への逆潮流発生時、前記複数種別の出力抑制事由の内、最も速い応答速度で前記インバータ（１３）の出力を抑制することを特徴とする項目３に記載の電力変換装置（１０）。
　これによれば、系統連系規程を満たすことができる。
［項目５］
　前記複数種別の出力抑制事由には、前記インバータ出力電力の定格電力を超える上昇、前記インバータ出力電流の定格電流を超える上昇、前記インバータ出力電圧の所定値を超える上昇、遠隔出力指令の受信、及び本電力変換装置（１０）内の温度の所定値を超える上昇が含まれ、これらの内で、前記インバータ出力電力の定格電力を超える上昇、及び前記インバータ出力電流の定格電流を超える上昇が優先度が最も高く、前記インバータ出力電圧の所定値を超える上昇が次に優先度が高く、前記遠隔出力指令の受信が次に優先度が高く、前記温度の所定値を超える上昇が最も優先度が低いことを特徴とする項目１から４のいずれかに記載の電力変換装置（１０）。
　これによれば、各出力抑制事由の優先度に応じた抑制制御が可能になり、各出力抑制事由に対する応答性を確保することができる。
［項目６］
　第１電力変換装置（１０）と第２電力変換装置（２０）を備える電力変換システム（１）であって、
　前記第１電力変換装置（１０）は、
　再生可能エネルギーをもとに発電する発電装置（２）の出力する直流電力の電圧を変換し、変換した直流電力を直流バス（４０）に出力する第１ＤＣ－ＤＣコンバータ（１１）と、
　前記第１ＤＣ－ＤＣコンバータ（１１）と前記直流バス（４０）を介して接続され、前記直流バス（４０）の直流電力を交流電力に変換し、変換した交流電力を負荷（５）または電力系統（４）に供給するインバータ（１３）と、
　前記インバータ（１３）を制御する第１制御回路（１４、１５）と、を有し、
　前記第２電力変換装置（２０）は、
　蓄電部（３）の入出力を制御する第２ＤＣ－ＤＣコンバータ（２１）と、
　前記第２ＤＣ－ＤＣコンバータ（２１）を制御する第２制御回路（２２）と、を有し、
　前記第１制御回路（１４、１５）は、前記第１電力変換装置（１０）の出力抑制事由の種別に応じて、前記インバータ（１３）の出力の抑制量を変えることを特徴とする電力変換システム（１）。
　これによれば、出力抑制事由の種別に応じた応答性を確保することができる。 [Item 1]
A first DC-DC converter (11) for converting the voltage of the DC power output from the power generator (2) that generates power based on renewable energy, and outputting the converted DC power to the DC bus (40);
Connected to the first DC-DC converter (11) via the DC bus (40), converts the DC power of the DC bus (40) into AC power, and converts the converted AC power into a load (5) or a power system An inverter (13) to be supplied to (4);
A control circuit (14, 15) for controlling the inverter (13),
The said control circuit (14,15) changes the amount of suppression of the output of the said inverter (13) according to the classification of the output suppression reason of this power converter device (10), The power converter device (10) characterized by the above-mentioned. .
According to this, the responsiveness according to the classification of the output suppression reason can be ensured.
[Item 2]
The control circuit (14, 15) suppresses an output suppression reason with the highest priority when two or more types of output suppression reasons occur among a plurality of types of output suppression reasons of the power conversion device (10). The power conversion device (10) according to item 1, wherein the output of the inverter (14) is suppressed by the amount and the response time.
According to this, even if multiple types of output suppression reasons occur at the same time, the required output suppression can be realized.
[Item 3]
A second DC-DC converter (21) for controlling input / output of the power storage unit (3) is connectable to the DC bus (40);
In the state where the second DC-DC converter (21) is connected to the DC bus (40), the reverse flow to the power system (4) is included with the highest priority in the multiple types of output suppression reasons. When the second DC-DC converter (21) is not connected to the DC bus (40), the plurality of types of output suppression reasons do not include reverse power flow to the power system (4). Item 3. The power conversion device (10) according to item 1 or 2,
According to this, an output suppression reason can be optimized according to whether or not the second DC-DC converter (21) is connected to the DC bus (40).
[Item 4]
The control circuit (14, 15) suppresses the output of the inverter (13) at the fastest response speed among the plurality of types of output suppression reasons when a reverse power flow to the system 4 occurs. Item 4. The power conversion device (10) according to item 3.
According to this, the grid connection regulations can be satisfied.
[Item 5]
The multiple types of output suppression reasons include an increase exceeding the rated power of the inverter output power, an increase exceeding the rated current of the inverter output current, an increase exceeding the predetermined value of the inverter output voltage, reception of a remote output command, and An increase exceeding a predetermined value of the temperature in the power converter (10) is included, and among these, an increase exceeding the rated power of the inverter output power and an increase exceeding the rated current of the inverter output current are priorities. Is the highest, the increase of the inverter output voltage exceeding the predetermined value is the next highest priority, the reception of the remote output command is the next highest priority, and the increase of the temperature exceeding the predetermined value is the lowest priority The power converter device (10) according to any one of items 1 to 4, characterized in that:
According to this, suppression control according to the priority of each output suppression reason is attained, and the responsiveness with respect to each output suppression reason can be ensured.
[Item 6]
A power conversion system (1) comprising a first power conversion device (10) and a second power conversion device (20),
The first power converter (10)
A first DC-DC converter (11) for converting the voltage of the DC power output from the power generator (2) that generates power based on renewable energy, and outputting the converted DC power to the DC bus (40);
Connected to the first DC-DC converter (11) via the DC bus (40), converts the DC power of the DC bus (40) into AC power, and converts the converted AC power into a load (5) or a power system An inverter (13) to be supplied to (4);
A first control circuit (14, 15) for controlling the inverter (13),
The second power converter (20)
A second DC-DC converter (21) for controlling input / output of the power storage unit (3);
A second control circuit (22) for controlling the second DC-DC converter (21),
The first control circuit (14, 15) changes an output suppression amount of the inverter (13) according to a type of an output suppression reason of the first power converter (10). System (1).
According to this, the responsiveness according to the classification of the output suppression reason can be ensured.
　１　電力変換システム、　Ｔ１　温度センサ、　２　太陽電池、　３　蓄電部、　４　系統、　５　負荷、　１０　第１電力変換装置、　１１　ＤＣ－ＤＣコンバータ、　１２　コンバータ制御回路、　１３　インバータ、　１４　インバータ制御回路、　１５　システム制御回路、　１５ａ　出力抑制制御部、　１５ｂ　指令値生成部、　２０　第２電力変換装置、　２１　ＤＣ－ＤＣコンバータ、　２２　コンバータ制御回路、　３０　操作表示装置、　４０　直流バス、　４１，４２，４３　通信線、　５０　配電線。 1 power conversion system, T1 temperature sensor, 2 solar battery, 3 power storage unit, 4 systems, 5 loads, 10 1st power converter, 11 DC-DC converter, 12 converter control circuit, 13 inverter, 14 inverter control circuit, 15 System control circuit, 15a Output suppression control unit, 15b Command value generation unit, 20 Second power conversion device, 21 DC-DC converter, 22 Converter control circuit, 30 Operation display device, 40 DC bus, 41, 42, 43 Communication line 50 distribution lines.
　本発明は、太陽電池と定置型蓄電池を組み合わせた分散型電源システムに利用可能である。 The present invention can be used for a distributed power supply system in which a solar battery and a stationary storage battery are combined.

Claims (6)

  1. 　再生可能エネルギーをもとに発電する発電装置の出力する直流電力の電圧を変換し、変換した直流電力を直流バスに出力する第１ＤＣ－ＤＣコンバータと、
    　前記第１ＤＣ－ＤＣコンバータと前記直流バスを介して接続され、前記直流バスの直流電力を交流電力に変換し、変換した交流電力を負荷または電力系統に供給するインバータと、
    　前記インバータを制御する制御回路と、を備え、
    　前記制御回路は、本電力変換装置の出力抑制事由の種別に応じて、前記インバータの出力の抑制量を変えることを特徴とする電力変換装置。     A first DC-DC converter that converts the voltage of DC power output from a power generator that generates power based on renewable energy, and outputs the converted DC power to a DC bus;
    An inverter connected to the first DC-DC converter via the DC bus, converting DC power of the DC bus into AC power, and supplying the converted AC power to a load or a power system;
    A control circuit for controlling the inverter,
    The said control circuit changes the amount of suppression of the output of the said inverter according to the classification of the output suppression reason of this power converter device, The power converter device characterized by the above-mentioned.
  2. 　前記制御回路は、本電力変換装置の複数種別の出力抑制事由の内、２つの種別以上の出力抑制事由が発生した場合、最も優先度の高い出力抑制事由に対する抑制量および応答時間で前記インバータの出力を抑制することを特徴とする請求項１に記載の電力変換装置。 When two or more types of output suppression reasons occur among the plurality of types of output suppression reasons of the power conversion device, the control circuit uses the amount of suppression and the response time for the highest priority output suppression reason. The power converter according to claim 1, wherein output is suppressed.
  3. 　蓄電部の入出力を制御する第２ＤＣ－ＤＣコンバータが、前記直流バスに接続可能な構成であり、
    　前記第２ＤＣ－ＤＣコンバータが前記直流バスに接続された状態では、前記複数種別の出力抑制事由に、前記電力系統への逆潮流が最も高い優先度で含まれており、前記第２ＤＣ－ＤＣコンバータが前記直流バスに非接続の状態では、前記複数種別の出力抑制事由に、前記電力系統への逆潮流が含まれないことを特徴とする請求項１または２に記載の電力変換装置。     A second DC-DC converter for controlling input / output of the power storage unit is connectable to the DC bus;
    In a state where the second DC-DC converter is connected to the DC bus, reverse flow to the power system is included with the highest priority for the plurality of types of output suppression reasons, and the second DC-DC converter 3. The power conversion device according to claim 1, wherein in a state in which the power source is not connected to the DC bus, the plurality of types of output suppression reasons do not include reverse power flow to the power system.
  4. 　前記制御回路は、前記系統への逆潮流発生時、前記複数種別の出力抑制事由の内、最も速い応答速度で前記インバータの出力を抑制することを特徴とする請求項３に記載の電力変換装置。 4. The power conversion device according to claim 3, wherein the control circuit suppresses the output of the inverter at the fastest response speed among the plurality of types of output suppression reasons when a reverse power flow to the system occurs. .
  5. 　前記複数種別の出力抑制事由には、前記インバータ出力電力の定格電力を超える上昇、前記インバータ出力電流の定格電流を超える上昇、前記インバータ出力電圧の所定値を超える上昇、遠隔出力指令の受信、及び本電力変換装置内の温度の所定値を超える上昇が含まれ、これらの内で、前記インバータ出力電力の定格電力を超える上昇、及び前記インバータ出力電流の定格電流を超える上昇が優先度が最も高く、前記インバータ出力電圧の所定値を超える上昇が次に優先度が高く、前記遠隔出力指令の受信が次に優先度が高く、前記温度の所定値を超える上昇が最も優先度が低いことを特徴とする請求項１から４のいずれかに記載の電力変換装置。 The multiple types of output suppression reasons include an increase exceeding the rated power of the inverter output power, an increase exceeding the rated current of the inverter output current, an increase exceeding the predetermined value of the inverter output voltage, reception of a remote output command, and An increase exceeding a predetermined value of the temperature in the power converter is included, and among these, an increase exceeding the rated power of the inverter output power and an increase exceeding the rated current of the inverter output current have the highest priority. An increase of the inverter output voltage exceeding a predetermined value has the next highest priority, reception of the remote output command has the next highest priority, and an increase of the temperature exceeding the predetermined value has the lowest priority. The power converter according to any one of claims 1 to 4.
  6. 　第１電力変換装置と第２電力変換装置を備える電力変換システムであって、
    　前記第１電力変換装置は、
    　再生可能エネルギーをもとに発電する発電装置の出力する直流電力の電圧を変換し、変換した直流電力を直流バスに出力する第１ＤＣ－ＤＣコンバータと、
    　前記第１ＤＣ－ＤＣコンバータと前記直流バスを介して接続され、前記直流バスの直流電力を交流電力に変換し、変換した交流電力を負荷または電力系統に供給するインバータと、
    　前記インバータを制御する第１制御回路と、を有し、
    　前記第２電力変換装置は、
    　蓄電部の入出力を制御する第２ＤＣ－ＤＣコンバータと、
    　前記第２ＤＣ－ＤＣコンバータを制御する第２制御回路と、を有し、
    　前記第１制御回路は、前記第１電力変換装置の出力抑制事由の種別に応じて、前記インバータの出力の抑制量を変えることを特徴とする電力変換システム。     A power conversion system comprising a first power conversion device and a second power conversion device,
    The first power converter is
    A first DC-DC converter that converts the voltage of DC power output from a power generator that generates power based on renewable energy, and outputs the converted DC power to a DC bus;
    An inverter connected to the first DC-DC converter via the DC bus, converting DC power of the DC bus into AC power, and supplying the converted AC power to a load or a power system;
    A first control circuit for controlling the inverter;
    The second power converter is
    A second DC-DC converter for controlling input / output of the power storage unit;
    A second control circuit for controlling the second DC-DC converter,
    The said 1st control circuit changes the amount of suppression of the output of the said inverter according to the classification of the output suppression reason of a said 1st power converter device, The power conversion system characterized by the above-mentioned.
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