WO2020255624A1 - Power conditioner - Google Patents

Power conditioner Download PDF

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Publication number
WO2020255624A1
WO2020255624A1 PCT/JP2020/020332 JP2020020332W WO2020255624A1 WO 2020255624 A1 WO2020255624 A1 WO 2020255624A1 JP 2020020332 W JP2020020332 W JP 2020020332W WO 2020255624 A1 WO2020255624 A1 WO 2020255624A1
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WO
WIPO (PCT)
Prior art keywords
value
command value
storage batteries
bidirectional
power command
Prior art date
Application number
PCT/JP2020/020332
Other languages
French (fr)
Japanese (ja)
Inventor
淳志 吉村
裕太 山本
Original Assignee
株式会社村田製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 株式会社村田製作所 filed Critical 株式会社村田製作所
Priority to JP2021527492A priority Critical patent/JP7211509B2/en
Publication of WO2020255624A1 publication Critical patent/WO2020255624A1/en

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • 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
    • H02J7/02—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
    • 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
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a power conditioner.
  • a power conversion device that converts and outputs the power output from each of a plurality of storage batteries and performs charge / discharge control so as to maximize the capacity of each of the plurality of storage batteries has been proposed (for example, see Patent Document 1).
  • This power conversion device compares the voltage average value of the voltage value of each of the plurality of storage batteries with the voltage value of each of the plurality of storage batteries. Then, the voltage converter increases the discharge power of the storage battery whose voltage value is larger than the voltage average value among the plurality of storage batteries when operating in the discharge operation mode, and the voltage value is higher than the voltage average value described above. Also controls to reduce the discharge power for small batteries.
  • the voltage converter reduces the charging power of a storage battery whose voltage value is larger than the voltage average value among a plurality of storage batteries when operating in the charging operation mode, and the voltage value is larger than the voltage average value described above. Also controls to increase the charging power for small batteries.
  • the present invention has been made in view of the above reasons, and provides a power conditioner capable of effectively utilizing the electricity stored in all of the plurality of storage batteries by equalizing the SOC values of the plurality of storage batteries.
  • the purpose is to do.
  • the power conditioner according to the present invention With multiple storage batteries DC bus line and One is provided between each of the plurality of storage batteries and the DC bus line, and the DC power output from any one of the plurality of storage batteries is converted and output to the DC bus line.
  • One of the plurality of storage batteries by executing the discharge from the storage batteries of the above or by converting the DC power supplied from the DC bus line and outputting it to any one of the plurality of storage batteries.
  • bidirectional DC-DC converters that operate in charge mode to charge one, For each of the plurality of bidirectional DC-DC converters, the discharge power command value when operating in the discharge mode or the charge power command value when operating in the charge mode is calculated, and the calculated discharge power command value or the said A command unit that outputs command value information indicating the charging power command value, and A DC-DC converter control unit that separately controls the plurality of bidirectional DC-DC converters based on the command value information output from the command unit is provided.
  • the command unit is based on the ratio of the total capacity of the plurality of storage batteries to the capacity of each of the plurality of storage batteries and the difference value of the SOC values of the plurality of storage batteries.
  • the discharge power command value or the charge power command value of each DC converter is calculated.
  • the power conditioner according to the present invention is The plurality of storage batteries are two storage batteries.
  • the command unit of the two storage batteries is based on a value obtained based on the ratio of the total capacity of the two storage batteries to the capacity of each of the two storage batteries and the SOC value of each of the two storage batteries.
  • the power conditioner according to the present invention is The command unit is the command value of the discharge power or the charge power from all of the two storage batteries to the ratio of the total capacity, which is the sum of the capacities of the two storage batteries, to the capacity of one of the two storage batteries.
  • a preset offset power command set to a value obtained by multiplying a certain total power command value by a SOC difference value obtained by subtracting the SOC value of the other storage battery from the SOC value of the one storage battery of the two storage batteries.
  • the discharge power command value or the charge power command value is calculated, and the ratio of the capacity of the other storage battery to the total capacity is multiplied by the total power command value.
  • the discharge power command value or the charge power command value may be calculated by subtracting the value obtained by multiplying the SOC difference value by the offset power command value from the value.
  • the power conditioner according to the present invention is When the calculated discharge power command value or the charge power command value is negative, the command unit may set the discharge power command value or the charge power command value to zero.
  • the power conditioner according to the present invention is When the calculated discharge power command value or the charge power command value exceeds the total power command value, the command unit sets the discharge power command value or the charge power command value to the total power command value. It may be.
  • the power conditioner according to the present invention is A voltage measuring unit for measuring the output voltage of each of the plurality of storage batteries is further provided.
  • the command unit calculates the SOC value of each of the plurality of storage batteries based on the output voltage of each of the plurality of storage batteries measured by the voltage measuring unit.
  • the offset power command value may be determined based on the measurement error of the output power of each of the plurality of storage batteries by the voltage measuring unit.
  • the power conditioner according to the present invention from another viewpoint is Two storage batteries and DC bus line and One is provided between each of the two storage batteries and the DC bus line, and the DC power output from any one of the two storage batteries is converted and output to the DC bus line.
  • One of the two storage batteries by performing a discharge mode for executing discharge from the two storage batteries or by converting the DC power supplied from the DC bus line and outputting it to any one of the two storage batteries.
  • Two bidirectional DC-DC converters that operate in charge mode to charge one, For each of the two bidirectional DC-DC converters, the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode is calculated, and the calculated discharge power command value or the said A command unit that outputs command value information indicating the charging power command value, and A DC-DC converter control unit that separately controls the two bidirectional DC-DC converters based on the command value information output from the command unit is provided.
  • the command unit When the two bidirectional DC-DC converters are operated in the discharge mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery
  • the discharge power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is larger than the gradient of the SOC value fluctuation with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery.
  • the bidirectional DC-DC converter corresponding to the one storage battery The charging power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is smaller than the gradient of the SOC value fluctuation with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery.
  • the power conditioner according to the present invention is The command unit When the two bidirectional DC-DC converters are operated in the discharge mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the other storage battery The discharge power command value is calculated so that the gradient of the fluctuation of the SOC value with respect to time becomes zero.
  • the bidirectional DC-DC converter corresponding to the one storage battery When the two bidirectional DC-DC converters are operated in the charging mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery
  • the charging power command value may be calculated so that the gradient of the fluctuation of the SOC value with respect to time becomes zero.
  • the power conditioner according to the present invention from another viewpoint is Two storage batteries and DC bus line and One is provided between each of the two storage batteries and the DC bus line, and the DC power output from any one of the two storage batteries is converted and output to the DC bus line.
  • One of the two storage batteries by performing a discharge mode for executing discharge from the two storage batteries or by converting the DC power supplied from the DC bus line and outputting it to any one of the two storage batteries.
  • Two bidirectional DC-DC converters that operate in charge mode to charge one, A DC-DC converter control unit that controls the two bidirectional DC-DC converters is provided.
  • the control unit Until the SOC value of one of the two storage batteries exceeds the SOC value of the other, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the one storage battery is determined.
  • the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the other storage battery is determined by the one storage battery.
  • the command unit uses a plurality of bidirectional DCs based on the ratio of the total capacity of the plurality of storage batteries to the capacity of each of the plurality of storage batteries and the difference value of the SOC values of the plurality of storage batteries. -Calculate the discharge power command value or charge power command value for each DC converter.
  • the SOC values of each of the plurality of storage batteries can be made closer to each other, so that the electricity stored in the storage batteries can be effectively used over the entire range from the fully charged state to the end of discharge state for all of the plurality of storage batteries. It can be used.
  • the power conversion device includes a plurality of storage batteries, a DC bus line, a plurality of bidirectional DC-DC converters, a command unit, and a DC-DC converter control unit.
  • the plurality of bidirectional DC-DC converters are provided between each of the plurality of storage batteries and the DC bus line, and convert the DC power output from the storage batteries and output the DC power to the DC bus line from the plurality of storage batteries. It operates in the discharge mode for executing the discharge of the above, or in the charge mode for charging the storage battery by converting the DC power supplied from the DC bus line and outputting it to the storage battery.
  • the command unit calculates the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode for each of the plurality of bidirectional DC-DC converters, and calculates the discharged power command value or charging. Outputs command value information indicating the power command value.
  • the DC-DC converter control unit controls a plurality of bidirectional DC-DC converters separately based on the command value information output from the command unit. Then, the command unit receives the discharge power command value of each of the plurality of bidirectional DC-DC converters based on the ratio of the capacities of the plurality of storage batteries to their total and the difference value of the SOC values of the plurality of storage batteries. Alternatively, the charging power command value is calculated.
  • the configuration of the power supply system including the power conversion device according to the present embodiment will be described.
  • the power supply system includes a solar cell 1, storage batteries 21, 22 and a power conditioner 3 connected to the solar cells 1, 2 storage batteries 21, 22 and a system power supply 4. And.
  • the grid power supply 4 supplies AC power to the power conditioner 3 in a single-phase three-wire system, for example.
  • the storage batteries 21 and 22, respectively are secondary batteries capable of extracting the stored electricity by electric discharge, and are lead storage batteries, nickel hydrogen batteries, lithium ion secondary batteries, lithium ion capacitors, and the like.
  • the storage batteries 21 and 22 may be a single battery as long as they output a preset electric power, or may be an assembled battery in which a plurality of single batteries are connected in series or in parallel.
  • the power conditioner 3 includes a PV converter 31, an inverter 32, two DC-DC converters 331 and 332, and a control circuit 39.
  • the PV converter 31, the inverter 32, and the DC-DC converters 331 and 332 are connected via the HVDC bus L3, which is a DC bus line.
  • a capacitor (not shown) for suppressing voltage fluctuations of the HVDC bus L3 is connected to the HVDC bus L3.
  • a line filter (not shown) that includes an inductor and a capacitor between the inverter 32 and the system power supply 4 and removes high-frequency switching noise components from the AC power output from the inverter 32. Is intervening.
  • the PV converter 31 is a DC-DC converter that boosts and outputs the DC voltage input from the solar cell 1. Even if the PV converter 31 has a function of adjusting the input voltage from the solar cell 1 by executing MPPT (Maximum Power Point Tracking) control based on the control signal input from the control circuit 39. Good.
  • the inverter 32 is a bidirectional DC-AC inverter, and has a plurality of switching elements (not shown) that are switched by a PWM (Pulse Width Modulation) signal input from the control circuit 39.
  • the inverter 32 converts the DC voltage input from the HVDC bus L3 into an AC voltage and outputs it, and also converts the AC voltage supplied from the system power supply 4 into a DC voltage and outputs it to the HVDC bus L3.
  • the DC-DC converters 331 and 332 are bidirectional DC-DC converters, respectively, and are provided between each of the two storage batteries 21 and 22 and the HVDC bus L3.
  • the DC-DC converters 331 and 332 are bidirectional chopper circuits as shown in FIG. 2, for example.
  • the DC-DC converters 331 and 332 have an inductor L3313 whose one end is connected to the terminal BH, a switching element Q1 which is connected between the other end of the inductor L3313 and the terminals BL and DL, and the other end and the terminal of the inductor L3313. It has a switching element Q2 connected to and from a DH. Further, a capacitor C1 is connected between the terminals DH and DL.
  • the switching elements Q1 and Q2 are each driven by a PWM (Pulse Width Modulation) signal input from the control circuit 39.
  • the terminal BL of the DC-DC converters 331 and 332 is connected to the negative electrode side of the storage batteries 21 and 22, and the terminal BH is connected to the positive electrode side of the storage batteries 21 and 22.
  • the terminal DL of the DC-DC converters 331 and 332 is connected to the negative side of the HVDC bus L3.
  • the terminal DH of the DC-DC converters 331 and 332 is connected to the positive side of the HVDC bus L3.
  • MOSFETs, IGBTs, etc. are used for the switching elements Q1 and Q2 of the DC-DC converters 331 and 332.
  • the DC-DC converters 331 and 332 use the voltage measuring unit 3311 for measuring the voltage between the terminals BH and BL, that is, the output voltage Vc of the storage batteries 21 and 22, and the voltage between the terminals DH and DL, that is, DC-. It has a voltage measuring unit 3312 for measuring the output voltage Vd of the DC converter.
  • the voltage measuring units 3311 and 3312 output measurement signals indicating the measured voltage values to the control circuit 39, respectively.
  • the DC-DC converters 331 and 332 convert the DC power output from the storage batteries 21 and 22, respectively, and output the DC power to the HVDC bus L3 to execute the discharge from the storage batteries 21 and 22, respectively, from the discharge mode or the HVDC bus L3. It operates in a charging mode in which the storage batteries 21 and 22 are charged by converting the supplied DC power and outputting it to the storage batteries 21 and 22.
  • the control circuit 39 has, for example, a DSP (Digital Signal Processor) and a memory.
  • the control circuit 39 includes a PV converter control unit 391, an inverter control unit 392, a DC-DC converter control units 3931 and 3932, and a command unit 394.
  • the memory of the control circuit 39 includes an SOC correlation storage unit 3951, a capacitance storage unit 3952, a reference command value storage unit 3953, and a command value storage unit 3954.
  • the PV converter control unit 391 generates a control signal for controlling the PV converter 31 so that its output voltage becomes constant, and outputs the control signal to the PV converter 31.
  • the inverter control unit 392 generates a control signal for operating the inverter 32 and outputs the control signal to the inverter 32.
  • the DC-DC converter control units 3931 and 3932 generate PWM signals for operating the DC-DC converters 331 and 332 in either the charge mode or the discharge mode, respectively, to generate the DC-DC converters 331 and 332, respectively. Output to each.
  • the DC-DC converter control units 3931 and 3932 are based on the measurement signals input from the voltage measurement units 3312 of the DC-DC converters 331 and 332, respectively, when the DC-DC converters 331 and 332 are operated in the discharge mode. Therefore, the duty ratio in the on / off operation of the switching element Q1 is controlled so that the output voltage Vd of the DC-DC converters 331 and 332 becomes constant.
  • the DC-DC converter control units 3931 and 3932 use the command value information output from the command unit 394 to indicate the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode. Based on this, the DC-DC converters 331 and 332 are controlled separately.
  • the SOC correlation storage unit 3951 stores correlation information indicating a correlation between the output voltage of the storage batteries 21 and 22 and the SOC value.
  • the command unit 394 acquires the voltage value of the output voltage Vc of the storage batteries 21 and 22 from the measurement signal input from the voltage measurement unit 3311, and calculates the SOC value of the storage batteries 21 and 22 based on the acquired voltage value. ..
  • the command unit 394 calculates the SOC value from the output voltages Vc of the storage batteries 21 and 22 with reference to the correlation information stored in the SOC correlation storage unit 3951. Further, the command unit 394 calculates the discharge power command value or the charge power command value for each of the two DC-DC converters 331 and 332, and generates command value information indicating the calculated discharge power command value or the charge power command value. And output.
  • the command unit 394 discharges the DC-DC converters 331 and 332, respectively, based on the ratio of the capacities of the storage batteries 21 and 22 to their total and the difference value of the SOC values of the storage batteries 21 and 22 respectively. Calculate the power command value or the charging power command value.
  • the command unit 394 calculates the discharge power command value or the charge power command value by using the relational expressions shown in the following equations (1) and (2).
  • PtA ⁇ PA / (PA + PB) ⁇ x K1 x Pt + (Sa-Sb) x k2 ... Equation (1)
  • PtB ⁇ PB / (PA + PB) ⁇ x K1 x Pt- (Sa-Sb) x k2 ...
  • PtA indicates, for example, the discharge power command value or the charge power command value of the DC-DC converter 331 corresponding to the storage battery 21
  • PtB is, for example, the discharge power command value or the discharge power command value of the DC-DC converter 332 corresponding to the storage battery 22.
  • PA and PB indicate the rated capacities of the storage batteries 21 and 22, respectively
  • Sa and Sb indicate the SOC values of the storage batteries 21 and 22, respectively.
  • Pt is a total power command value which is a command value of discharge power or charge power from all the storage batteries 21 and 22, and K1 is a coefficient based on the deterioration state of the storage battery and the cumulative number of charge / discharge cycles.
  • the offset power command value k2 is a preset offset power command value. For example, when charging the storage batteries 21 and 22 by 2 [kW] or discharging the storage batteries 21 and 22 by 2 [kW], the total power command value Pt is set to 2 [kW].
  • the offset power command value k2 is determined based on the measurement error of the output voltage of each of the storage batteries 21 and 22 by the voltage measuring unit 3311. Specifically, the offset power command value k2 is set to a value equal to or higher than a value obtained by multiplying the measurement error of the output power of each of the storage batteries 21 and 22 by the voltage measuring unit 3311 by a preset current value, for example. .. Further, the upper limit of the offset power command value k2 is determined based on, for example, the time required for the SOC values of the storage batteries 21 and 22 to become equal. This offset power command value k2 is set to, for example, 0.1 [kW].
  • the command unit 394 sets the offset power command value k2 to the SOC difference value (Sa-Sb) to the value obtained by multiplying the ratio of the rated capacity PA of the storage battery 21 to the total capacity (PA + PB) by the total power command value Pt. By adding the value obtained by multiplying, the discharge power command value or the charge power command value of the DC-DC converter 331 is calculated.
  • the total capacity (PA + PB) is the sum of the rated capacities PA and PB of the storage batteries 21 and 22
  • the SOC difference value (Sa-Sb) is the SOC value Sa of the storage battery 21 minus the SOC value Sb of the storage battery 22. Sa and Sb are expressed as percentages (%).
  • the command unit 394 issues an offset power command to the SOC difference value (Sa-Sb) from a value obtained by multiplying the ratio of the rated capacity PB of the storage battery 22 to the total capacity (PA + PB) by the coefficient K1 and the total power command value Pt. By multiplying the value k2 and subtracting the obtained value, the discharge power command value or the charge power command value of the DC-DC converter 332 is calculated. Then, the command unit 394 stores the calculated discharge power command value or information indicating the charge power command value in the command value storage unit 3954.
  • the command unit 394 sets the information indicating the discharge power command value or charge power command value stored in the command value storage unit 3954 to "0". To do. Further, when the calculated discharge power command value or charge power command value exceeds the above-mentioned total power command value Pt, the command unit 394 forcibly sets the discharge power command value or charge power command value to the total power command value Pt. To do.
  • the reason why the information stored in the command value storage unit 3954 is set to "0" when the calculated discharge power command value or the charge power command value is negative is to prevent the acceleration of battery deterioration.
  • the operation is such that one storage battery is discharged and the other storage battery is charged, so that the deterioration of the storage battery is accelerated.
  • the capacity storage unit 3952 stores capacity information indicating the rated capacity of each of the storage batteries 21 and 22.
  • the command value storage unit 3954 stores information indicating the discharge power command value or the charge power command value calculated by the command unit 394.
  • the reference command value storage unit 3953 has the coefficient K1 in the above equations (1) and (2), the total power command value information indicating the total power command value Pt, and the offset power command value information indicating the offset power command value k2. And remember.
  • the reference command value storage unit 3953 stores one type of total power command value information and offset power command value information indicating two types of positive and negative offset power command values k2.
  • the command unit 394 uses the relational expressions shown in the following equations (1) and (2) to calculate the discharge power command value or the charge power command value, and the capacity information and the reference command value stored in the capacity storage unit 3952.
  • the total power command value information and the offset power command value information stored in the storage unit 3953 are referred to.
  • This power command value setting process is started when the power conditioner 3 is activated.
  • the control circuit 39 controls the operation of the PV converter 31, the operation of the inverter 32, and the operation of the DC-DC converters 331 and 332 in parallel with the execution of the power command value setting process. Execute the process to be performed.
  • the command unit 394 acquires the voltage value of the output voltage of the storage batteries 21 and 22 from the measurement signal input from the voltage measurement unit 3311 (step S101). Next, the command unit 394 calculates the SOC values of the storage batteries 21 and 22 based on the acquired voltage value and the SOC correlation table (step S102).
  • the command unit 394 determines whether or not the DC-DC converters 331 and 332 are operating in the charging mode (step S103). It is assumed that the command unit 394 determines that the DC-DC converters 331 and 332 are operating in the charging mode (step S103: Yes). In this case, the command unit 394 refers to the offset power command value information stored in the reference command value storage unit 3953, and sets a negative offset power command as the offset power command value k2 in the above equations (1) and (2). The value k2 is adopted (step S104). On the other hand, it is assumed that the command unit 394 determines that the DC-DC converters 3931 and 3932 are operating in the discharge mode (step S103: No).
  • the command unit 394 refers to the offset power command value information stored in the reference command value storage unit 3953, and sets a positive offset power command as the offset power command value k2 in the above equations (1) and (2).
  • the value k2 is adopted (step S105).
  • the command unit 394 uses the rated capacities of the storage batteries 21 and 22, the coefficient K1, the above-mentioned total power command value Pt, the offset power command value k2 adopted in the above-mentioned step S104 or step S105, and the above-mentioned formula.
  • the command unit 394 stores the calculated discharge power command value or information indicating the charge power command value in the command value storage unit 3954 (step S106).
  • the command unit 394 acquires the rated capacity of each of the storage batteries 21 and 22 by referring to the capacity information indicating the rated capacity of each of the storage batteries 21 and 22 stored in the capacity storage unit 3952.
  • step S107 the command unit 394 determines whether or not any of the calculated discharge power command value or charge power command value PtA and PtB is less than 0 (step S107).
  • step S107: No the command unit 394 directly executes the process of step S109 described later.
  • step S109: Yes it is assumed that the command unit 394 determines that either the calculated discharge power command value or the charge power command value PtA or PtB is less than 0, that is, negative (step S107: Yes).
  • the command unit 394 updates the information indicating the negative discharge power command value or the charge power command value PtA, PtB stored in the command value storage unit 3945 to the information indicating "0" (step S108). .. That is, when the calculated discharge power command value or the charge power command value is negative, the command unit 394 sets the discharge power command value or the charge power command value to zero.
  • the command unit 394 determines whether or not any of the calculated discharge power command value or charge power command value PtA or PtB is larger than the total power command value Pt (step S109).
  • the command unit 394 determines that the calculated discharge power command value or charge power command value PtA or PtB is equal to or less than the total power command value Pt (step S109: No)
  • the command unit 394 directly executes the process of step S111 described later.
  • the command unit 394 stores information indicating the discharge power command value or the charge power command value PtA, PtB, which is larger than the total power command value Pt, stored in the command value storage unit 3945, and information indicating the total power command value Pt. Update to (step S110). That is, when the calculated discharge power command value or charge power command value exceeds the above-mentioned total power command value Pt, the command unit 394 sets the discharge power command value or charge power command value to the total power command value Pt.
  • the command unit 394 outputs command value information indicating the discharge power command value or the charge power command values PtA and PtB stored in the command value storage unit 3945 to the DC-DC converter control units 3931 and 3932 (step S111). .. At this time, the DC-DC converter control units 3931 and 3932 separately control the DC-DC converters 331 and 332 based on the discharge power command value or the charge power command value indicating the discharge power command value output from the command unit 394. To do. Next, the process of step S101 is executed again.
  • the power conditioner according to the comparative example has the same configuration as the power conditioner 3 according to the present embodiment, and only the calculation method of the discharge power command value or the charge power command value of the command unit 394 is the same as that of the present embodiment. It's different.
  • the command unit 394 according to the comparative example calculates the discharge power command value or the charge power command value by using the relational expressions shown in the following formulas (3) and (4).
  • PtA [PA ⁇ (1-Sa) / ⁇ (PA ⁇ (1-Sa) + PB ⁇ (1-Sb) ⁇ ] ⁇ 2 ⁇ ⁇ ⁇ Equation (3)
  • PtB [PB ⁇ (1-Sb) / ⁇ (PA ⁇ (1-Sa) + PB ⁇ (1-Sb) ⁇ ] ⁇ 2 ⁇ ⁇ ⁇ Equation (4)
  • PtA, PtB, PA, PB, Sa, and Sb are the same as those in the above formulas (1) and (2), respectively.
  • the command unit 394 For example, the rated capacity of the storage battery 21 is 4 [kWh], the rated capacity of the storage battery 22 is 2 [kWh], the SOC value of the storage battery 21 is "0.5 (50%)”, and the SOC value of the storage battery 22 is "0. 4 (40%) ”.
  • the command unit 394 sets the charge power command value to the storage battery 21 to [4 ⁇ (1-0.5) / ⁇ 4 ⁇ (1-0.5) by using the relational expression shown in the equation (3).
  • FIG. 5 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 after the DC-DC converters 331 and 332 are started to operate in the charging mode.
  • the difference value of the SOC values of the storage batteries 21 and 22 is measured over time for about 10 minutes after the DC-DC converters 331 and 332 start operating in the charging mode. Decrease. However, when 10 minutes or more have passed, it can be seen that the difference value of the SOC values of the storage batteries 21 and 22 is almost constant. Therefore, the SOC values of the storage batteries 21 and 22 cannot be made equal.
  • the SOC value of the storage battery 21 is 0.9 (90%) and the SOC value of the storage battery 22 is 0.1 (10%).
  • the time required to reduce the difference value of the SOC values of the storage batteries 21 and 22 to some extent may become long.
  • the command unit 394 uses the relational expressions shown in the above equations (1) and (2) to generate a discharge power command value or a charge power command value. Is calculated. For example, the rated capacity of the storage battery 21 is 4 [kWh], the rated capacity of the storage battery 22 is 2 [kWh], the SOC value of the storage battery 21 is "0.5 (50%)", and the SOC value of the storage battery 22 is "0 (" 0%) ”. Then, it is assumed that the command unit 394 operates the DC-DC converters 331 and 332 in the charging mode and sets the above-mentioned total power command value Pt to 2 [kW]. Further, it is assumed that the offset power command value is set to 0.1 [kW].
  • the command unit 394 when the command unit 394 operates the DC-DC converters 331 and 332 in the charging mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the bidirectional DC-DC converter 331 corresponding to the storage battery 21 The charging power command value for is set to "0" so that the storage battery 21 is not charged.
  • the command unit 394 sets the charging power command value for the bidirectional DC-DC converter 332 corresponding to the storage battery 22 to a value larger than "0" to charge the storage battery 22.
  • the command unit 394 when the command unit 394 operates the DC-DC converters 331 and 332 in the charging mode and the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the command unit 394 relates to the DC-DC converter 331 corresponding to the storage battery 21.
  • the charging power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is smaller than the gradient of the SOC value fluctuation with respect to time for the DC-DC converter 332 corresponding to the storage battery 22.
  • the charging power command value for each of the DC-DC converters 331 and 332 is not limited to the above.
  • FIG. 6 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 after the DC-DC converters 331 and 332 are started to operate in the charging mode for the power conditioner 3 according to the present embodiment. ..
  • the SOC value of the storage battery 21 is approximately "0.5 (50%)" for about 20 minutes after the DC-DC converters 331 and 332 start operating in the charging mode. Be maintained.
  • the SOC value of the storage battery 22 continues to increase. Along with this, the difference value of the SOC values of the storage batteries 21 and 22 decreases.
  • FIG. 7 shows an enlarged view of the portion of the storage batteries 21 and 22 in FIG. 6 in which the SOC values are finally equalized (the portion surrounded by the broken line A1 in FIG. 6).
  • the curve S11 corresponding to the storage battery 21 and the curve S12 corresponding to the storage battery 22 are not completely overlapped with each other, and the magnitude relations are always alternately alternated. Converges with. That is, at the beginning of charging, the slope of the curve S11 corresponding to the storage battery 21 is gentle and the slope of the curve S12 corresponding to the storage battery 22 is relatively steep depending on the offset power command value. As a result, the curve S11 corresponding to the storage battery 21 and the curve S12 corresponding to the storage battery 22 intersect each other at a certain SOC value, and then the magnitude relationship of the curves S11 and S12 is reversed.
  • the command unit 394 gives a charging command so that the curve S11 corresponding to the storage battery 21 becomes steep and the curve S12 corresponding to the storage battery 22 becomes relatively gentle. Since the value is set, the magnitude relationship of the curves S11 and S12 is reversed again. Then, as this process is repeated, the curve S11 corresponding to the storage battery 21 and the curve S12 corresponding to the storage battery 22 converge in a state in which they appear to overlap when viewed macroscopically. This means that the SOC values of the storage batteries 21 and 22 are "equal". This phenomenon is the same not only when operating in the charging mode but also when operating in the discharging mode described later.
  • the rated capacity of the storage battery 21 is 4 [kWh]
  • the rated capacity of the storage battery 22 is 2 [kWh]
  • the SOC value of the storage battery 21 is "1.0 (100%)”
  • the SOC value of the storage battery 22 is "1.0 (100%)”. It is assumed that it is "0.5 (50%)”.
  • the command unit 394 operates the DC-DC converters 331 and 332 in the discharge mode and sets the above-mentioned total power command value Pt to 2 [kW]. Further, it is assumed that the offset power command value is set to 0.1 [kW].
  • the command unit 394 when the command unit 394 operates the DC-DC converters 331 and 332 in the discharge mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the command unit 394 relates to the DC-DC converter 331 corresponding to the storage battery 21.
  • the discharge power command value is set to a value larger than "0" to discharge the storage battery 21.
  • the command unit 394 does not discharge the storage battery 22 by setting the discharge power command value for the DC-DC converter 332 corresponding to the storage battery 22 to “0”.
  • the command unit 394 operates the DC-DC converters 331 and 332 in the discharge mode
  • the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22
  • the DC-DC converter 331 corresponding to the storage battery 21 The discharge power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is larger than the gradient of the SOC value fluctuation with respect to time for the DC-DC converter 332 corresponding to the storage battery 22.
  • the discharge power command values for the DC-DC converters 331 and 332 are not limited to the above.
  • FIG. 8 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 after the DC-DC converters 331 and 332 are started to operate in the discharge mode for the power conditioner 3 according to the present embodiment. ..
  • the SOC value of the storage battery 22 is approximately "50% (0.5)" for about 45 minutes after the DC-DC converters 331 and 332 start operating in the discharge mode. Be maintained.
  • the SOC value of the storage battery 21 continues to decrease. Along with this, the difference value of the SOC values of the storage batteries 21 and 22 decreases.
  • the storage battery 22 started to be discharged, and the SOC value of the storage battery 22 gradually decreased.
  • the rate of decrease in the SOC value of the storage battery 22 also becomes gradual.
  • the SOC values of the storage batteries 21 and 22 are finally equal due to the offset power command values in the above equations (1) and (2).
  • FIG. 9 shows an enlarged view of the portion (the portion surrounded by the broken line A2 in FIG. 6) in which the SOC values of the storage batteries 21 and 22 are finally equal in FIG.
  • the command unit 394 operates the DC-DC converters 331 and 332 in the discharge mode
  • the command unit 394 relates to the time for the DC-DC converter 331 corresponding to the storage battery 21.
  • the charging power command value is calculated so that the absolute value of the slope of the fluctuation of the SOC value becomes a value larger than the absolute value of the slope of the fluctuation of the SOC value with respect to the time of the DC-DC converter 332 corresponding to the storage battery 22. Therefore, as shown in FIG.
  • the curve S21 corresponding to the storage battery 21 and the curve S22 corresponding to the storage battery 22 are not completely overlapped with each other, and the magnitude relations are always alternately alternated. Converges with. That is, at the beginning of discharge, the slope of the curve S21 corresponding to the storage battery 21 is steep and the slope of the curve S22 corresponding to the storage battery 22 is relatively gentle due to the offset power command value. As a result, the curve S21 corresponding to the storage battery 21 and the curve S22 corresponding to the storage battery 22 intersect each other at a certain SOC value, and then the magnitude relationship of the curves S21 and S22 is reversed.
  • the command unit 394 makes the slope of the curve S21 corresponding to the storage battery 21 gentle and the slope of the curve S22 corresponding to the storage battery 22 relatively steep. Since the charging command value is set as described above, the magnitude relationship of the curves S21 and S22 is reversed again. Then, as this process is repeated, the curve S21 corresponding to the storage battery 21 and the curve S22 corresponding to the storage battery 22 converge in a state in which they appear to overlap when viewed macroscopically. This means that the SOC values of the storage batteries 21 and 22 are "equal".
  • the storage batteries 21 and 22 are charged with 2 [kW] and the storage batteries 21 and 22 are charged. It is assumed that the discharge of 2 [kW] from the above is repeated alternately at intervals of 10 minutes.
  • the rated capacity of the storage battery 21 is 4 [kWh]
  • the rated capacity of the storage battery 22 is 2 [kWh]
  • the SOC value of the storage battery 21 is "1.0 (100%)”
  • the SOC value of the storage battery 22 is. It is assumed to be "0.5 (50%)”.
  • FIG. 10 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 in this case. As shown in the curves S31 and S32 of FIG.
  • the period during which the DC-DC converters 331 and 332 are operating in the discharge mode (for example, a period between the start and 10 minutes or 20 to 30 minutes after the start).
  • the time transition of the SOC values of the storage batteries 21 and 22 is the same as the time transition described with reference to FIG. 8 described above.
  • the time transition of the SOC values of the storage batteries 21 and 22 is described above. The time transition is the same as that described with reference to FIG. Even in this case, the SOC values of the storage batteries 21 and 22 are finally equal due to the offset power command values in the above equations (1) and (2).
  • the charging power command value or the discharge corresponding to the storage batteries 21 and 22 is used by using the equations (1) and (2) including the offset power command value term. Calculate the power command value. As a result, even if there is a large deviation in the SOC values of the storage batteries 21 and 22, the SOC values of the storage batteries 21 and 22 can be made equal quickly and surely.
  • the command unit 394 determines the ratio of the rated capacities of the storage batteries 21 and 22 to the total of them and the SOC value of each of the storage batteries 21 and 22. Based on the difference value, the discharge power command value or the charge power command value of each of the DC-DC converters 331 and 332 is calculated. As a result, the SOC values of the storage batteries 21 and 22 can be set to be equal to each other, so that the electricity stored in the storage batteries can be stored in the entire range from the fully charged state to the end-discharged state of all the storage batteries 21 and 22. It can be used effectively.
  • the difference between the SOC values of the storage batteries 21 and 22 becomes large for example, when the DC-DC converters 331 and 332 are operated in the charging mode, for example, when the storage battery 21 is fully charged, the other storage battery 22 cannot be charged. Things can happen. In order to prevent such a situation, it is preferable to adjust the SOC values of the storage batteries 21 and 22 so as to be as equal as possible.
  • the charging power to the storage values 21 and 22 or the discharging power from the storage batteries 21 and 22 is distributed in consideration of the SOC values and the rated capacities of the storage batteries 21 and 22 respectively. However, the SOC values of the storage batteries 21 and 22 cannot be equalized.
  • the discharge power command is performed by using the relational expression including the term related to the offset power command value as in the relational expression shown in the above equations (1) and (2). Calculate the value or the charge power command value.
  • the SOC values of the storage batteries 21 and 22 can be made equal.
  • the two lines do not intersect because the amount of distribution changes in real time. This tendency is remarkable when a storage battery is added because the current capacity is different. If it remains misaligned, the battery life will be shortened.
  • the command unit 394 when the calculated discharge power command value or charge power command value is negative, the command unit 394 according to the present embodiment forcibly sets the discharge power command value or the charge power command value to zero. As a result, during the operating period of the power conditioner 3, the ratio of the period during which the storage batteries 21 and 22 are discharged or the ratio of the period during which the storage batteries 21 and 22 are charged can be reduced. Deterioration can be suppressed.
  • the command unit 394 sets the discharge power command value or the charge power command value as the total power command value when the calculated discharge power command value or the charge power command value exceeds the total power command value. ..
  • the occurrence of over-discharging or over-charging of the storage batteries 21 and 22 can be suppressed, so that damage to the storage batteries 21 and 22 can be suppressed.
  • the power conditioner 3 may include three or more storage batteries.
  • the command unit 394 when the DC-DC converter corresponding to each of the three or more storage batteries operates in the discharge mode, the command unit 394 has the lowest SOC value among the SOC values of the three or more storage batteries and the other storage batteries. Based on the value obtained by multiplying the difference value from each SOC value by the offset power command value, the discharge command value is calculated from the storage battery with the highest SOC value, and if the total power command value is reached in the middle, the rest. The storage battery should not be discharged.
  • the charging command value is calculated from the storage battery having the lowest SOC value, and if the total power command value is reached in the middle, the remaining storage batteries may not be charged.
  • the present invention is suitable as a power conditioner including a plurality of storage batteries.

Abstract

A power conditioner comprising: two storage batteries; an HVDC bus; DC–DC converters (331, 332) that operate in a discharge mode or a charge mode; a command unit (394) that outputs command value information; and DC–DC converter control units (3931, 3932) that individually control the DC–DC converters (331, 332), on the basis of the command value information. The command unit 394 calculates the discharge power command value or charge power command value for each of the DC–DC converters (3931, 3932), on the basis of: the ratio between the total capacity of the two storage batteries to the capacity of each of the two storage batteries; and the difference between the SOC values for each of the two storage batteries.

Description

パワーコンディショナPower conditioner
　本発明は、パワーコンディショナに関する。 The present invention relates to a power conditioner.
　複数の蓄電池それぞれから出力される電力を変換して出力する電力変換装置であって、複数の蓄電池それぞれの容量を最大限に利用できるように充放電制御を行う電力変換装置が提案されている（例えば特許文献１参照）。この電力変換装置は、複数の蓄電池それぞれの電圧値の電圧平均値と、複数の蓄電池それぞれの電圧値とを比較する。そして、電圧変換装置は、放電運転モードでの動作時において、複数の蓄電池のうち、その電圧値が電圧平均値よりも大きい蓄電池について放電電力を増加させ、その電圧値が前述の電圧平均値よりも小さい蓄電池について放電電力を減少させるように制御する。また、電圧変換装置は、充電運転モードでの動作時において、複数の蓄電池のうち、その電圧値が電圧平均値よりも大きい蓄電池について充電電力を減少させ、その電圧値が前述の電圧平均値よりも小さい蓄電池について充電電力を増加させるように制御する。 A power conversion device that converts and outputs the power output from each of a plurality of storage batteries and performs charge / discharge control so as to maximize the capacity of each of the plurality of storage batteries has been proposed ( For example, see Patent Document 1). This power conversion device compares the voltage average value of the voltage value of each of the plurality of storage batteries with the voltage value of each of the plurality of storage batteries. Then, the voltage converter increases the discharge power of the storage battery whose voltage value is larger than the voltage average value among the plurality of storage batteries when operating in the discharge operation mode, and the voltage value is higher than the voltage average value described above. Also controls to reduce the discharge power for small batteries. Further, the voltage converter reduces the charging power of a storage battery whose voltage value is larger than the voltage average value among a plurality of storage batteries when operating in the charging operation mode, and the voltage value is larger than the voltage average value described above. Also controls to increase the charging power for small batteries.
特開２０１０－１４８２４２号公報JP-A-2010-148242
　しかしながら、特許文献１に記載された電力変換装置では、複数の蓄電池それぞれのＳＯＣ（State of Charge）値を互いにある程度近づけることができるが、複数の蓄電池それぞれのＳＯＣ値を互いに等しい値にすることができず、複数の蓄電池間でＳＯＣ値の偏りが発生してしまう。この場合、複数の蓄電池の全てについて満充電状態から放電終止状態までの全範囲に亘って蓄電池に蓄えられた電気を利用することができない虞がある。また、複数の蓄電池それぞれのＳＯＣ値に乖離があると、ある程度のＳＯＣ値に近づくまでに長時間がかかってしまう。なお、放電終止とは、ＳＯＣ＝０の状態を示す。 However, in the power conversion device described in Patent Document 1, although the SOC (State of Charge) values of the plurality of storage batteries can be brought close to each other to some extent, the SOC values of the plurality of storage batteries can be set to be equal to each other. This is not possible, and the SOC value is biased among a plurality of storage batteries. In this case, there is a possibility that the electricity stored in the storage batteries cannot be used over the entire range from the fully charged state to the end of discharge state for all of the plurality of storage batteries. Further, if there is a discrepancy in the SOC values of each of the plurality of storage batteries, it takes a long time to approach a certain SOC value. Note that the discharge termination indicates a state of SOC = 0.
　本発明は、上記事由に鑑みてなされたものであり、複数の蓄電池それぞれのＳＯＣ値を等しくすることにより複数の蓄電池の全てについて蓄えられた電気を有効に利用することができるパワーコンディショナを提供することを目的とする。 The present invention has been made in view of the above reasons, and provides a power conditioner capable of effectively utilizing the electricity stored in all of the plurality of storage batteries by equalizing the SOC values of the plurality of storage batteries. The purpose is to do.
　上記目的を達成するために、本発明に係るパワーコンディショナは、
　複数の蓄電池と、
　直流バスラインと、
　前記複数の蓄電池それぞれと前記直流バスラインとの間に１つずつ設けられ、前記複数の蓄電池のいずれか１つから出力される直流電力を変換して前記直流バスラインへ出力することにより前記複数の蓄電池からの放電を実行する放電モードまたは前記直流バスラインから供給される直流電力を変換して前記複数の蓄電池のうちのいずれか１つへ出力することにより前記複数の蓄電池のうちのいずれか１つを充電する充電モードで動作する複数の双方向ＤＣ－ＤＣコンバータと、
　前記複数の双方向ＤＣ－ＤＣコンバータそれぞれについて、前記放電モードで動作する場合の放電電力指令値または前記充電モードで動作する場合の充電電力指令値を算出し、算出した前記放電電力指令値または前記充電電力指令値を示す指令値情報を出力する指令部と、
　前記指令部から出力される前記指令値情報に基づいて、前記複数の双方向ＤＣ－ＤＣコンバータを各別に制御するＤＣ－ＤＣコンバータ制御部と、を備え、
　前記指令部は、前記複数の蓄電池それぞれの容量に対する、前記複数の蓄電池の容量の総和の比率と、前記複数の蓄電池それぞれのＳＯＣ値の差分値と、に基づいて、前記複数の双方向ＤＣ－ＤＣコンバータそれぞれの前記放電電力指令値または前記充電電力指令値を算出する。 In order to achieve the above object, the power conditioner according to the present invention
With multiple storage batteries
DC bus line and
One is provided between each of the plurality of storage batteries and the DC bus line, and the DC power output from any one of the plurality of storage batteries is converted and output to the DC bus line. One of the plurality of storage batteries by executing the discharge from the storage batteries of the above or by converting the DC power supplied from the DC bus line and outputting it to any one of the plurality of storage batteries. Multiple bidirectional DC-DC converters that operate in charge mode to charge one,
For each of the plurality of bidirectional DC-DC converters, the discharge power command value when operating in the discharge mode or the charge power command value when operating in the charge mode is calculated, and the calculated discharge power command value or the said A command unit that outputs command value information indicating the charging power command value, and
A DC-DC converter control unit that separately controls the plurality of bidirectional DC-DC converters based on the command value information output from the command unit is provided.
The command unit is based on the ratio of the total capacity of the plurality of storage batteries to the capacity of each of the plurality of storage batteries and the difference value of the SOC values of the plurality of storage batteries. The discharge power command value or the charge power command value of each DC converter is calculated.
　また、本発明に係るパワーコンディショナは、
　前記複数の蓄電池は、２つの蓄電池であり、
　前記指令部は、２つの蓄電池それぞれの容量に対する、前記２つの蓄電池の容量の総和の比率に基づいて得られる値と、前記２つの蓄電池それぞれのＳＯＣ値と、に基づいて、前記２つの蓄電池のうちのいずれか一方に対応する双方向ＤＣ－ＤＣコンバータについての前記放電電力指令値または前記充電電力指令値と、前記２つの蓄電池のうちの他方に対応する双方向ＤＣ－ＤＣコンバータについての前記放電電力指令値または前記充電電力指令値と、を算出する、ものであってもよい。 The power conditioner according to the present invention is
The plurality of storage batteries are two storage batteries.
The command unit of the two storage batteries is based on a value obtained based on the ratio of the total capacity of the two storage batteries to the capacity of each of the two storage batteries and the SOC value of each of the two storage batteries. The discharge power command value or the charge power command value for the bidirectional DC-DC converter corresponding to any one of them, and the discharge for the bidirectional DC-DC converter corresponding to the other of the two storage batteries. It may be the one that calculates the power command value or the charging power command value.
　また、本発明に係るパワーコンディショナは、
　前記指令部は、２つの蓄電池のうちのいずれか一方の容量に対する、前記２つの蓄電池の容量の総和である総容量の比率に前記２つの蓄電池の全てからの放電電力または充電電力の指令値である総電力指令値を乗じて得られる値に、前記２つの蓄電池のうちの前記一方の蓄電池のＳＯＣ値から他方の蓄電池のＳＯＣ値を差し引いて得られるＳＯＣ差分値に予め設定されたオフセット電力指令値を乗じて得られる値を加えることにより、前記放電電力指令値または前記充電電力指令値を算出し、前記他方の蓄電池の容量の前記総容量に対する比率に前記総電力指令値を乗じて得られる値から、前記ＳＯＣ差分値に前記オフセット電力指令値を乗じて得られる値を差し引くことにより、前記放電電力指令値または前記充電電力指令値を算出する、ものであってもよい。 The power conditioner according to the present invention is
The command unit is the command value of the discharge power or the charge power from all of the two storage batteries to the ratio of the total capacity, which is the sum of the capacities of the two storage batteries, to the capacity of one of the two storage batteries. A preset offset power command set to a value obtained by multiplying a certain total power command value by a SOC difference value obtained by subtracting the SOC value of the other storage battery from the SOC value of the one storage battery of the two storage batteries. By adding a value obtained by multiplying the value, the discharge power command value or the charge power command value is calculated, and the ratio of the capacity of the other storage battery to the total capacity is multiplied by the total power command value. The discharge power command value or the charge power command value may be calculated by subtracting the value obtained by multiplying the SOC difference value by the offset power command value from the value.
　また、本発明に係るパワーコンディショナは、
　前記指令部は、算出した前記放電電力指令値または前記充電電力指令値が負である場合、前記放電電力指令値または前記充電電力指令値をゼロに設定する、ものであってもよい。 The power conditioner according to the present invention is
When the calculated discharge power command value or the charge power command value is negative, the command unit may set the discharge power command value or the charge power command value to zero.
　また、本発明に係るパワーコンディショナは、
　前記指令部は、算出した前記放電電力指令値または前記充電電力指令値が前記総電力指令値を超える場合、前記放電電力指令値または前記充電電力指令値を前記総電力指令値に設定する、ものであってもよい。 The power conditioner according to the present invention is
When the calculated discharge power command value or the charge power command value exceeds the total power command value, the command unit sets the discharge power command value or the charge power command value to the total power command value. It may be.
　また、本発明に係るパワーコンディショナは、
　前記複数の蓄電池それぞれの出力電圧を計測する電圧計測部を更に備え、
　前記指令部は、前記電圧計測部により計測された前記複数の蓄電池それぞれの出力電圧に基づいて、前記複数の蓄電池それぞれのＳＯＣ値を算出し、
　前記オフセット電力指令値は、前記電圧計測部による前記複数の蓄電池それぞれの出力電力の計測誤差に基づいて決定される、ものであってもよい。 The power conditioner according to the present invention is
A voltage measuring unit for measuring the output voltage of each of the plurality of storage batteries is further provided.
The command unit calculates the SOC value of each of the plurality of storage batteries based on the output voltage of each of the plurality of storage batteries measured by the voltage measuring unit.
The offset power command value may be determined based on the measurement error of the output power of each of the plurality of storage batteries by the voltage measuring unit.
　他の観点から見た本発明に係るパワーコンディショナは、
　２つの蓄電池と、
　直流バスラインと、
　前記２つの蓄電池それぞれと前記直流バスラインとの間に１つずつ設けられ、前記２つの蓄電池のいずれか１つから出力される直流電力を変換して前記直流バスラインへ出力することにより前記２つの蓄電池からの放電を実行する放電モードまたは前記直流バスラインから供給される直流電力を変換して前記２つの蓄電池のうちのいずれか１つへ出力することにより前記２つの蓄電池のうちのいずれか１つを充電する充電モードで動作する２つの双方向ＤＣ－ＤＣコンバータと、
　前記２つの双方向ＤＣ－ＤＣコンバータそれぞれについて、前記放電モードで動作させる場合の放電電力指令値または前記充電モードで動作させる場合の充電電力指令値を算出し、算出した前記放電電力指令値または前記充電電力指令値を示す指令値情報を出力する指令部と、
　前記指令部から出力される前記指令値情報に基づいて、前記２つの双方向ＤＣ－ＤＣコンバータを各別に制御するＤＣ－ＤＣコンバータ制御部と、を備え、
　前記指令部は、
　前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように前記放電電力指令値を算出し、
　前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように前記充電電力指令値を算出する。 The power conditioner according to the present invention from another viewpoint is
Two storage batteries and
DC bus line and
One is provided between each of the two storage batteries and the DC bus line, and the DC power output from any one of the two storage batteries is converted and output to the DC bus line. One of the two storage batteries by performing a discharge mode for executing discharge from the two storage batteries or by converting the DC power supplied from the DC bus line and outputting it to any one of the two storage batteries. Two bidirectional DC-DC converters that operate in charge mode to charge one,
For each of the two bidirectional DC-DC converters, the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode is calculated, and the calculated discharge power command value or the said A command unit that outputs command value information indicating the charging power command value, and
A DC-DC converter control unit that separately controls the two bidirectional DC-DC converters based on the command value information output from the command unit is provided.
The command unit
When the two bidirectional DC-DC converters are operated in the discharge mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery The discharge power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is larger than the gradient of the SOC value fluctuation with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery. And
When the two bidirectional DC-DC converters are operated in the charging mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery The charging power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is smaller than the gradient of the SOC value fluctuation with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery. To do.
　また、本発明に係るパワーコンディショナは、
　前記指令部は、
　前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きがゼロとなるように前記放電電力指令値を算出し、
　前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きがゼロとなるように前記充電電力指令値を算出する、ものであってもよい。 The power conditioner according to the present invention is
The command unit
When the two bidirectional DC-DC converters are operated in the discharge mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the other storage battery The discharge power command value is calculated so that the gradient of the fluctuation of the SOC value with respect to time becomes zero.
When the two bidirectional DC-DC converters are operated in the charging mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery The charging power command value may be calculated so that the gradient of the fluctuation of the SOC value with respect to time becomes zero.
　他の観点から見た本発明に係るパワーコンディショナは、
　２つの蓄電池と、
　直流バスラインと、
　前記２つの蓄電池それぞれと前記直流バスラインとの間に１つずつ設けられ、前記２つの蓄電池のいずれか１つから出力される直流電力を変換して前記直流バスラインへ出力することにより前記２つの蓄電池からの放電を実行する放電モードまたは前記直流バスラインから供給される直流電力を変換して前記２つの蓄電池のうちのいずれか１つへ出力することにより前記２つの蓄電池のうちのいずれか１つを充電する充電モードで動作する２つの双方向ＤＣ－ＤＣコンバータと、
　前記２つの双方向ＤＣ－ＤＣコンバータを制御するＤＣ－ＤＣコンバータ制御部と、を備え、
　前記制御部は、
　前記２つの蓄電池のうちの一方の蓄電池のＳＯＣ値が他方のＳＯＣ値を超えるまでの間、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる第１制御と、前記他方の蓄電池のＳＯＣ値が前記一方のＳＯＣ値を超えるまでの間、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる第２制御と、前記一方の蓄電池のＳＯＣ値が前記他方のＳＯＣ値を超えるまでの間、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる第３制御と、前記他方の蓄電池のＳＯＣ値が前記一方のＳＯＣ値を超えるまでの間、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる第４制御と、のうちのいずれ１つを選択して、前記２つの双方向ＤＣ－ＤＣコンバータを制御することが可能であり、前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる場合、前記第１制御と前記第２制御とを交互に実行し、前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる場合、前記第３制御と前記第４制御とを交互に実行する。 The power conditioner according to the present invention from another viewpoint is
Two storage batteries and
DC bus line and
One is provided between each of the two storage batteries and the DC bus line, and the DC power output from any one of the two storage batteries is converted and output to the DC bus line. One of the two storage batteries by performing a discharge mode for executing discharge from the two storage batteries or by converting the DC power supplied from the DC bus line and outputting it to any one of the two storage batteries. Two bidirectional DC-DC converters that operate in charge mode to charge one,
A DC-DC converter control unit that controls the two bidirectional DC-DC converters is provided.
The control unit
Until the SOC value of one of the two storage batteries exceeds the SOC value of the other, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the one storage battery is determined. The first control for operating the two bidirectional DC-DC converters in the discharge mode so that the value is larger than the gradient of the fluctuation of the SOC value with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery. And, until the SOC value of the other storage battery exceeds the SOC value of the one, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the other storage battery is determined by the one storage battery. The second control for operating the two bidirectional DC-DC converters in the discharge mode so that the value becomes larger than the gradient of the fluctuation of the SOC value with respect to time for the bidirectional DC-DC converter corresponding to the above. Until the SOC value of one storage battery exceeds the SOC value of the other storage battery, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the other storage battery corresponds to the one storage battery. A third control for operating the two bidirectional DC-DC converters in the charging mode and the other storage battery so that the value becomes smaller than the gradient of the fluctuation of the SOC value with respect to time for the bidirectional DC-DC converter. The slope of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the one storage battery until the SOC value of the above exceeds the SOC value of the other storage battery. Any one of the fourth control for operating the two bidirectional DC-DC converters in the charging mode so that the value is smaller than the gradient of the fluctuation of the SOC value with respect to the time for the -DC converter. When the two bidirectional DC-DC converters can be selectively controlled and the two bidirectional DC-DC converters are operated in the discharge mode, the first control and the second control When the two bidirectional DC-DC converters are operated in the charging mode, the third control and the fourth control are alternately executed.
　本発明によれば、指令部が、複数の蓄電池それぞれの容量に対する、複数の蓄電池の容量の総和の比率と、複数の蓄電池それぞれのＳＯＣ値の差分値と、に基づいて、複数の双方向ＤＣ－ＤＣコンバータそれぞれの放電電力指令値または充電電力指令値を算出する。これにより、複数の蓄電池それぞれのＳＯＣ値をより近い値にすることができるので、複数の蓄電池の全てについて満充電状態から放電終止状態までの全範囲に亘って蓄電池に蓄えられた電気を有効に利用することができる。 According to the present invention, the command unit uses a plurality of bidirectional DCs based on the ratio of the total capacity of the plurality of storage batteries to the capacity of each of the plurality of storage batteries and the difference value of the SOC values of the plurality of storage batteries. -Calculate the discharge power command value or charge power command value for each DC converter. As a result, the SOC values of each of the plurality of storage batteries can be made closer to each other, so that the electricity stored in the storage batteries can be effectively used over the entire range from the fully charged state to the end of discharge state for all of the plurality of storage batteries. It can be used.
本発明の実施の形態に係る電源システムの構成を示す図である。It is a figure which shows the structure of the power-source system which concerns on embodiment of this invention. 実施の形態に係るＤＣ－ＤＣコンバータの回路図である。It is a circuit diagram of the DC-DC converter which concerns on embodiment. 実施の形態に係る制御回路のブロック図である。It is a block diagram of the control circuit which concerns on embodiment. 実施の形態に係る制御回路が実行する電力指令値設定処理の流れの一例を示すフローチャートである。It is a flowchart which shows an example of the flow of the power command value setting process executed by the control circuit which concerns on embodiment. 比較例に係るパワーコンディショナにおける蓄電池のＳＯＣ値の推移を示す図である。It is a figure which shows the transition of the SOC value of the storage battery in the power conditioner which concerns on a comparative example. 実施の形態に係るパワーコンディショナにおける蓄電池のＳＯＣ値の推移を示す図である。It is a figure which shows the transition of the SOC value of the storage battery in the power conditioner which concerns on embodiment. 図６の破線Ａ１で囲んだ部分の拡大図である。It is an enlarged view of the part surrounded by the broken line A1 of FIG. 実施の形態に係るパワーコンディショナにおける蓄電池のＳＯＣ値の推移を示す図である。It is a figure which shows the transition of the SOC value of the storage battery in the power conditioner which concerns on embodiment. 図８の破線Ａ２で囲んだ部分の拡大図である。It is an enlarged view of the part surrounded by the broken line A2 of FIG. 実施の形態に係るパワーコンディショナにおける蓄電池のＳＯＣ値の推移を示す図である。It is a figure which shows the transition of the SOC value of the storage battery in the power conditioner which concerns on embodiment.
　以下、本発明の実施の形態について図面を参照して詳細に説明する。本実施の形態に係る電力変換装置は、複数の蓄電池と、直流バスラインと、複数の双方向ＤＣ－ＤＣコンバータと、指令部と、ＤＣ－ＤＣコンバータ制御部と、を備える。複数の双方向ＤＣ－ＤＣコンバータは、それぞれ、複数の蓄電池それぞれと直流バスラインとの間に設けられ、蓄電池から出力される直流電力を変換して直流バスラインへ出力することにより複数の蓄電池からの放電を実行する放電モードまたは直流バスラインから供給される直流電力を変換して蓄電池へ出力することにより蓄電池を充電する充電モードで動作する。指令部は、複数の双方向ＤＣ－ＤＣコンバータそれぞれについて、放電モードで動作する場合の放電電力指令値または充電モードで動作する場合の充電電力指令値を算出し、算出した放電電力指令値または充電電力指令値を示す指令値情報を出力する。ＤＣ－ＤＣコンバータ制御部は、指令部から出力される指令値情報に基づいて、複数の双方向ＤＣ－ＤＣコンバータを各別に制御する。そして、指令部は、複数の蓄電池それぞれの容量のそれらの総和に対する比率と、複数の蓄電池それぞれのＳＯＣ値の差分値と、に基づいて、複数の双方向ＤＣ－ＤＣコンバータそれぞれの放電電力指令値または充電電力指令値を算出する。ここで、本実施の形態に係る電力変換装置を含む電源システムの構成について説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The power conversion device according to the present embodiment includes a plurality of storage batteries, a DC bus line, a plurality of bidirectional DC-DC converters, a command unit, and a DC-DC converter control unit. The plurality of bidirectional DC-DC converters are provided between each of the plurality of storage batteries and the DC bus line, and convert the DC power output from the storage batteries and output the DC power to the DC bus line from the plurality of storage batteries. It operates in the discharge mode for executing the discharge of the above, or in the charge mode for charging the storage battery by converting the DC power supplied from the DC bus line and outputting it to the storage battery. The command unit calculates the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode for each of the plurality of bidirectional DC-DC converters, and calculates the discharged power command value or charging. Outputs command value information indicating the power command value. The DC-DC converter control unit controls a plurality of bidirectional DC-DC converters separately based on the command value information output from the command unit. Then, the command unit receives the discharge power command value of each of the plurality of bidirectional DC-DC converters based on the ratio of the capacities of the plurality of storage batteries to their total and the difference value of the SOC values of the plurality of storage batteries. Alternatively, the charging power command value is calculated. Here, the configuration of the power supply system including the power conversion device according to the present embodiment will be described.
　本実施の形態に係る電源システムは、図１に示すように、太陽電池１と、蓄電池２１、２２と、太陽電池１、２つの蓄電池２１、２２および系統電源４に接続されたパワーコンディショナ３と、を備える。系統電源４は、例えば単相三線式でパワーコンディショナ３へ交流電力を供給する。蓄電池２１、２２は、それぞれ、蓄えられた電気を放電により取り出すことができる二次電池であり、鉛蓄電池、ニッケル水素電池、リチウムイオン二次電池、リチウムイオンキャパシタ等である。また、蓄電池２１、２２は、予め設定された電力を出力するものであれば、単電池であってもよいし、複数の単電池を直列または並列に接続した組電池であってもよい。 As shown in FIG. 1, the power supply system according to the present embodiment includes a solar cell 1, storage batteries 21, 22 and a power conditioner 3 connected to the solar cells 1, 2 storage batteries 21, 22 and a system power supply 4. And. The grid power supply 4 supplies AC power to the power conditioner 3 in a single-phase three-wire system, for example. The storage batteries 21 and 22, respectively, are secondary batteries capable of extracting the stored electricity by electric discharge, and are lead storage batteries, nickel hydrogen batteries, lithium ion secondary batteries, lithium ion capacitors, and the like. Further, the storage batteries 21 and 22 may be a single battery as long as they output a preset electric power, or may be an assembled battery in which a plurality of single batteries are connected in series or in parallel.
　パワーコンディショナ３は、ＰＶコンバータ３１と、インバータ３２と、２つのＤＣ－ＤＣコンバータ３３１、３３２と、制御回路３９と、を備える。ＰＶコンバータ３１と、インバータ３２と、ＤＣ－ＤＣコンバータ３３１、３３２とは、直流バスラインであるＨＶＤＣバスＬ３を介して接続されている。また、ＨＶＤＣバスＬ３には、ＨＶＤＣバスＬ３の電圧変動を抑制するためのコンデンサ（図示せず）が接続されている。また、インバータ３２と系統電源４との間には、インダクタとコンデンサとを含んで構成され、インバータ３２から出力される交流電力から、高周波数のスイッチングノイズ成分を除去するラインフィルタ（図示せず）が介在している。 The power conditioner 3 includes a PV converter 31, an inverter 32, two DC- DC converters 331 and 332, and a control circuit 39. The PV converter 31, the inverter 32, and the DC- DC converters 331 and 332 are connected via the HVDC bus L3, which is a DC bus line. Further, a capacitor (not shown) for suppressing voltage fluctuations of the HVDC bus L3 is connected to the HVDC bus L3. A line filter (not shown) that includes an inductor and a capacitor between the inverter 32 and the system power supply 4 and removes high-frequency switching noise components from the AC power output from the inverter 32. Is intervening.
　ＰＶコンバータ３１は、太陽電池１から入力される直流電圧を昇圧して出力するＤＣ－ＤＣコンバータである。ＰＶコンバータ３１は、制御回路３９から入力される制御信号に基づいて、ＭＰＰＴ（Maximum Power Point Tracking）制御を実行することにより、太陽電池１からの入力電圧を調整する機能を有するものであってもよい。インバータ３２は、双方向型ＤＣ－ＡＣインバータであり、制御回路３９から入力されるＰＷＭ（Pulse Width Modulation）信号によりスイッチングされる複数のスイッチング素子（図示せず）を有する。このインバータ３２は、ＨＶＤＣバスＬ３から入力される直流電圧を交流電圧に変換して出力するとともに、系統電源４から供給される交流電圧を直流電圧に変換してＨＶＤＣバスＬ３へ出力する。 The PV converter 31 is a DC-DC converter that boosts and outputs the DC voltage input from the solar cell 1. Even if the PV converter 31 has a function of adjusting the input voltage from the solar cell 1 by executing MPPT (Maximum Power Point Tracking) control based on the control signal input from the control circuit 39. Good. The inverter 32 is a bidirectional DC-AC inverter, and has a plurality of switching elements (not shown) that are switched by a PWM (Pulse Width Modulation) signal input from the control circuit 39. The inverter 32 converts the DC voltage input from the HVDC bus L3 into an AC voltage and outputs it, and also converts the AC voltage supplied from the system power supply 4 into a DC voltage and outputs it to the HVDC bus L3.
　ＤＣ－ＤＣコンバータ３３１、３３２は、それぞれ、双方向ＤＣ－ＤＣコンバータであり、２つの蓄電池２１、２２それぞれとＨＶＤＣバスＬ３との間に１つずつ設けられている。ＤＣ－ＤＣコンバータ３３１、３３２は、例えば図２に示すような双方向チョッパ回路である。ＤＣ－ＤＣコンバータ３３１、３３２は、一端が端子ＢＨに接続されたインダクタＬ３３１３と、インダクタＬ３３１３の他端と端子ＢＬ、ＤＬとの間に接続されたスイッチング素子Ｑ１と、インダクタＬ３３１３の他端と端子ＤＨとの間に接続されたスイッチング素子Ｑ２と、を有する。また、端子ＤＨ、ＤＬ間には、コンデンサＣ１が接続されている。スイッチング素子Ｑ１、Ｑ２は、それぞれ、制御回路３９から入力されるＰＷＭ（Pulse Width Modulation）信号により駆動される。ＤＣ―ＤＣコンバータ３３１、３３２の端子ＢＬは蓄電池２１、２２の負極側に接続され、端子ＢＨは蓄電池２１、２２の正極側に接続される。また、ＤＣ－ＤＣコンバータ３３１、３３２の端子ＤＬはＨＶＤＣバスＬ３の負側に接続される。ＤＣ－ＤＣコンバータ３３１、３３２の端子ＤＨはＨＶＤＣバスＬ３の正側に接続される。ＤＣ－ＤＣコンバータ３３１、３３２のスイッチング素子Ｑ１、Ｑ２には、ＭＯＳＦＥＴ、ＩＧＢＴ等が採用される。また、ＤＣ―ＤＣコンバータ３３１、３３２は、端子ＢＨ、ＢＬ間の電圧、即ち、蓄電池２１、２２の出力電圧Ｖｃを計測する電圧計測部３３１１と、端子ＤＨ、ＤＬ間の電圧、即ち、ＤＣ－ＤＣコンバータの出力電圧Ｖｄを計測する電圧計測部３３１２と、を有する。電圧計測部３３１１、３３１２は、それぞれ、計測した電圧値を示す計測信号を制御回路３９へ出力する。 The DC- DC converters 331 and 332 are bidirectional DC-DC converters, respectively, and are provided between each of the two storage batteries 21 and 22 and the HVDC bus L3. The DC- DC converters 331 and 332 are bidirectional chopper circuits as shown in FIG. 2, for example. The DC- DC converters 331 and 332 have an inductor L3313 whose one end is connected to the terminal BH, a switching element Q1 which is connected between the other end of the inductor L3313 and the terminals BL and DL, and the other end and the terminal of the inductor L3313. It has a switching element Q2 connected to and from a DH. Further, a capacitor C1 is connected between the terminals DH and DL. The switching elements Q1 and Q2 are each driven by a PWM (Pulse Width Modulation) signal input from the control circuit 39. The terminal BL of the DC- DC converters 331 and 332 is connected to the negative electrode side of the storage batteries 21 and 22, and the terminal BH is connected to the positive electrode side of the storage batteries 21 and 22. Further, the terminal DL of the DC- DC converters 331 and 332 is connected to the negative side of the HVDC bus L3. The terminal DH of the DC- DC converters 331 and 332 is connected to the positive side of the HVDC bus L3. MOSFETs, IGBTs, etc. are used for the switching elements Q1 and Q2 of the DC- DC converters 331 and 332. Further, the DC- DC converters 331 and 332 use the voltage measuring unit 3311 for measuring the voltage between the terminals BH and BL, that is, the output voltage Vc of the storage batteries 21 and 22, and the voltage between the terminals DH and DL, that is, DC-. It has a voltage measuring unit 3312 for measuring the output voltage Vd of the DC converter. The voltage measuring units 3311 and 3312 output measurement signals indicating the measured voltage values to the control circuit 39, respectively.
　ＤＣ－ＤＣコンバータ３３１、３３２は、それぞれ、蓄電池２１、２２から出力される直流電力を変換してＨＶＤＣバスＬ３へ出力することにより蓄電池２１、２２からの放電を実行する放電モードまたはＨＶＤＣバスＬ３から供給される直流電力を変換して蓄電池２１、２２へ出力することにより蓄電池２１、２２を充電する充電モードで動作する。 The DC- DC converters 331 and 332 convert the DC power output from the storage batteries 21 and 22, respectively, and output the DC power to the HVDC bus L3 to execute the discharge from the storage batteries 21 and 22, respectively, from the discharge mode or the HVDC bus L3. It operates in a charging mode in which the storage batteries 21 and 22 are charged by converting the supplied DC power and outputting it to the storage batteries 21 and 22.
　図１に戻って、制御回路３９は、例えばＤＳＰ（Digital Signal Processor）とメモリとを有する。制御回路３９は、図３に示すように、ＰＶコンバータ制御部３９１と、インバータ制御部３９２と、ＤＣ－ＤＣコンバータ制御部３９３１、３９３２と、指令部３９４と、を有する。制御回路３９のメモリは、ＳＯＣ相関記憶部３９５１と、容量記憶部３９５２と、基準指令値記憶部３９５３と、指令値記憶部３９５４と、を有する。ＰＶコンバータ制御部３９１は、ＰＶコンバータ３１をその出力電圧が一定になるように制御するための制御信号を生成してＰＶコンバータ３１へ出力する。インバータ制御部３９２は、インバータ３２を動作させるための制御信号を生成してインバータ３２へ出力する。 Returning to FIG. 1, the control circuit 39 has, for example, a DSP (Digital Signal Processor) and a memory. As shown in FIG. 3, the control circuit 39 includes a PV converter control unit 391, an inverter control unit 392, a DC-DC converter control units 3931 and 3932, and a command unit 394. The memory of the control circuit 39 includes an SOC correlation storage unit 3951, a capacitance storage unit 3952, a reference command value storage unit 3953, and a command value storage unit 3954. The PV converter control unit 391 generates a control signal for controlling the PV converter 31 so that its output voltage becomes constant, and outputs the control signal to the PV converter 31. The inverter control unit 392 generates a control signal for operating the inverter 32 and outputs the control signal to the inverter 32.
　ＤＣ－ＤＣコンバータ制御部３９３１、３９３２は、それぞれ、ＤＣ－ＤＣコンバータ３３１、３３２を充電モードまたは放電モードのいずれかの動作モードで動作させるためのＰＷＭ信号を生成してＤＣ－ＤＣコンバータ３３１、３３２それぞれへ出力する。ここで、ＤＣ―ＤＣコンバータ制御部３９３１、３９３２は、ＤＣ―ＤＣコンバータ３３１、３３２を放電モードで動作させる場合、ＤＣ―ＤＣコンバータ３３１、３３２それぞれの電圧計測部３３１２から入力される計測信号に基づいて、ＤＣ―ＤＣコンバータ３３１、３３２の出力電圧Ｖｄが一定となるようにスイッチング素子Ｑ１のオンオフ動作におけるデューティ比を制御する。また、ＤＣ－ＤＣコンバータ制御部３９３１、３９３２は、指令部３９４から出力される、放電モードで動作する場合の放電電力指令値または充電モードで動作する場合の充電電力指令値を示す指令値情報に基づいて、ＤＣ―ＤＣコンバータ３３１、３３２を各別に制御する。 The DC-DC converter control units 3931 and 3932 generate PWM signals for operating the DC- DC converters 331 and 332 in either the charge mode or the discharge mode, respectively, to generate the DC- DC converters 331 and 332, respectively. Output to each. Here, the DC-DC converter control units 3931 and 3932 are based on the measurement signals input from the voltage measurement units 3312 of the DC- DC converters 331 and 332, respectively, when the DC- DC converters 331 and 332 are operated in the discharge mode. Therefore, the duty ratio in the on / off operation of the switching element Q1 is controlled so that the output voltage Vd of the DC- DC converters 331 and 332 becomes constant. Further, the DC-DC converter control units 3931 and 3932 use the command value information output from the command unit 394 to indicate the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode. Based on this, the DC- DC converters 331 and 332 are controlled separately.
　ＳＯＣ相関記憶部３９５１は、蓄電池２１、２２の出力電圧とＳＯＣ値と相関関係を示す相関情報を記憶する。 The SOC correlation storage unit 3951 stores correlation information indicating a correlation between the output voltage of the storage batteries 21 and 22 and the SOC value.
　指令部３９４は、電圧計測部３３１１から入力される計測信号から、蓄電池２１、２２の出力電圧Ｖｃの電圧値を取得し、取得した電圧値に基づいて、蓄電池２１、２２のＳＯＣ値を算出する。ここで、指令部３９４は、ＳＯＣ相関記憶部３９５１が記憶する相関情報を参照して、蓄電池２１、２２の出力電圧ＶｃからＳＯＣ値を算出する。また、指令部３９４は、２つのＤＣ―ＤＣコンバータ３３１、３３２それぞれについて、放電電力指令値または充電電力指令値を算出し、算出した放電電力指令値または充電電力指令値を示す指令値情報を生成して出力する。ここで、指令部３９４は、蓄電池２１、２２それぞれの容量のそれらの総和に対する比率と、蓄電池２１、２２それぞれのＳＯＣ値の差分値と、に基づいて、ＤＣ―ＤＣコンバータ３３１、３３２それぞれの放電電力指令値または充電電力指令値を算出する。 The command unit 394 acquires the voltage value of the output voltage Vc of the storage batteries 21 and 22 from the measurement signal input from the voltage measurement unit 3311, and calculates the SOC value of the storage batteries 21 and 22 based on the acquired voltage value. .. Here, the command unit 394 calculates the SOC value from the output voltages Vc of the storage batteries 21 and 22 with reference to the correlation information stored in the SOC correlation storage unit 3951. Further, the command unit 394 calculates the discharge power command value or the charge power command value for each of the two DC- DC converters 331 and 332, and generates command value information indicating the calculated discharge power command value or the charge power command value. And output. Here, the command unit 394 discharges the DC- DC converters 331 and 332, respectively, based on the ratio of the capacities of the storage batteries 21 and 22 to their total and the difference value of the SOC values of the storage batteries 21 and 22 respectively. Calculate the power command value or the charging power command value.
　具体的には、指令部３９４は、下記式（１）および式（２）に示す関係式を用いて、放電電力指令値または充電電力指令値を算出する。
ＰｔＡ＝｛ＰＡ／（ＰＡ＋ＰＢ）｝×Ｋ１×Ｐｔ＋（Ｓａ－Ｓｂ）×ｋ２　　　・・・式（１）
ＰｔＢ＝｛ＰＢ／（ＰＡ＋ＰＢ）｝×Ｋ１×Ｐｔ－（Ｓａ－Ｓｂ）×ｋ２　　　・・・式（２）
　ここで、ＰｔＡは、例えば蓄電池２１に対応するＤＣ―ＤＣコンバータ３３１の放電電力指令値または充電電力指令値を示し、ＰｔＢは、例えば蓄電池２２に対応するＤＣ―ＤＣコンバータ３３２の放電電力指令値または充電電力指令値を示す。この場合、ＰＡ、ＰＢは、それぞれ、蓄電池２１、２２の定格容量を示し、Ｓａ、Ｓｂは、それぞれ、蓄電池２１、２２のＳＯＣ値を示す。また、Ｐｔは、蓄電池２１、２２全てからの放電電力または充電電力の指令値である総電力指令値であり、Ｋ１は、蓄電池の劣化状態や累積充放電回数などを基にした係数であり、ｋ２は、予め設定されたオフセット電力指令値である。例えば蓄電池２１、２２へ２［ｋＷ］充電する場合または蓄電池２１、２２から２［ｋＷ］放電する場合、総電力指令値Ｐｔは、２［ｋＷ］に設定される。オフセット電力指令値ｋ２は、電圧計測部３３１１による蓄電池２１、２２それぞれの出力電圧の計測誤差に基づいて決定される。具体的には、オフセット電力指令値ｋ２は、例えば、電圧計測部３３１１による蓄電池２１、２２それぞれの出力電力の計測誤差に予め設定された電流値を乗じて得られる値以上の値に設定される。また、オフセット電力指令値ｋ２の上限は、例えば蓄電池２１、２２のＳＯＣ値が等しくなるまでに要する時間に基づいて決定される。このオフセット電力指令値ｋ２は、例えば０．１［ｋＷ］に設定される。 Specifically, the command unit 394 calculates the discharge power command value or the charge power command value by using the relational expressions shown in the following equations (1) and (2).
PtA = {PA / (PA + PB)} x K1 x Pt + (Sa-Sb) x k2 ... Equation (1)
PtB = {PB / (PA + PB)} x K1 x Pt- (Sa-Sb) x k2 ... Equation (2)
Here, PtA indicates, for example, the discharge power command value or the charge power command value of the DC-DC converter 331 corresponding to the storage battery 21, and PtB is, for example, the discharge power command value or the discharge power command value of the DC-DC converter 332 corresponding to the storage battery 22. Indicates the charging power command value. In this case, PA and PB indicate the rated capacities of the storage batteries 21 and 22, respectively, and Sa and Sb indicate the SOC values of the storage batteries 21 and 22, respectively. Further, Pt is a total power command value which is a command value of discharge power or charge power from all the storage batteries 21 and 22, and K1 is a coefficient based on the deterioration state of the storage battery and the cumulative number of charge / discharge cycles. k2 is a preset offset power command value. For example, when charging the storage batteries 21 and 22 by 2 [kW] or discharging the storage batteries 21 and 22 by 2 [kW], the total power command value Pt is set to 2 [kW]. The offset power command value k2 is determined based on the measurement error of the output voltage of each of the storage batteries 21 and 22 by the voltage measuring unit 3311. Specifically, the offset power command value k2 is set to a value equal to or higher than a value obtained by multiplying the measurement error of the output power of each of the storage batteries 21 and 22 by the voltage measuring unit 3311 by a preset current value, for example. .. Further, the upper limit of the offset power command value k2 is determined based on, for example, the time required for the SOC values of the storage batteries 21 and 22 to become equal. This offset power command value k2 is set to, for example, 0.1 [kW].
　即ち、指令部３９４は、蓄電池２１の定格容量ＰＡの総容量（ＰＡ＋ＰＢ）に対する比率に総電力指令値Ｐｔを乗じて得られる値に、ＳＯＣ差分値（Ｓａ－Ｓｂ）にオフセット電力指令値ｋ２を乗じて得られる値を加えることにより、ＤＣ―ＤＣコンバータ３３１の放電電力指令値または充電電力指令値を算出する。ここで、総容量（ＰＡ＋ＰＢ）は、蓄電池２１、２２の定格容量ＰＡ、ＰＢの総和であり、ＳＯＣ差分値（Ｓａ－Ｓｂ）は、蓄電池２１のＳＯＣ値Ｓａから蓄電池２２のＳＯＣ値Ｓｂを差し引いて得られる値であり、ＳａおよびＳｂは百分率（％）で表記される。また、指令部３９４は、蓄電池２２の定格容量ＰＢの総容量（ＰＡ＋ＰＢ）に対する比率に係数Ｋ１と総電力指令値Ｐｔを乗じて得られる値から、ＳＯＣ差分値（Ｓａ－Ｓｂ）にオフセット電力指令値ｋ２を乗じて得られる値を差し引くことにより、ＤＣ―ＤＣコンバータ３３２の放電電力指令値または充電電力指令値を算出する。そして、指令部３９４は、算出した放電電力指令値または充電電力指令値を示す情報を指令値記憶部３９５４に記憶させる。 That is, the command unit 394 sets the offset power command value k2 to the SOC difference value (Sa-Sb) to the value obtained by multiplying the ratio of the rated capacity PA of the storage battery 21 to the total capacity (PA + PB) by the total power command value Pt. By adding the value obtained by multiplying, the discharge power command value or the charge power command value of the DC-DC converter 331 is calculated. Here, the total capacity (PA + PB) is the sum of the rated capacities PA and PB of the storage batteries 21 and 22, and the SOC difference value (Sa-Sb) is the SOC value Sa of the storage battery 21 minus the SOC value Sb of the storage battery 22. Sa and Sb are expressed as percentages (%). Further, the command unit 394 issues an offset power command to the SOC difference value (Sa-Sb) from a value obtained by multiplying the ratio of the rated capacity PB of the storage battery 22 to the total capacity (PA + PB) by the coefficient K1 and the total power command value Pt. By multiplying the value k2 and subtracting the obtained value, the discharge power command value or the charge power command value of the DC-DC converter 332 is calculated. Then, the command unit 394 stores the calculated discharge power command value or information indicating the charge power command value in the command value storage unit 3954.
　また、指令部３９４は、算出した放電電力指令値または充電電力指令値が負である場合、指令値記憶部３９５４が記憶する放電電力指令値または充電電力指令値を示す情報を「０」に設定する。更に、指令部３９４は、算出した放電電力指令値または充電電力指令値が前述の総電力指令値Ｐｔを超える場合、放電電力指令値または充電電力指令値を強制的に総電力指令値Ｐｔに設定する。ここで、算出した放電電力指令値または充電電力指令値が負である場合に、指令値記憶部３９５４が記憶する情報を「０」にする理由は、電池の劣化の加速を防ぐためである。指令値記憶部３９５４が記憶する情報を「０」にしない場合、一方の蓄電池を放電させ、他方の蓄電池を充電させるような動作になるため蓄電池の劣化を加速させる。 Further, when the calculated discharge power command value or charge power command value is negative, the command unit 394 sets the information indicating the discharge power command value or charge power command value stored in the command value storage unit 3954 to "0". To do. Further, when the calculated discharge power command value or charge power command value exceeds the above-mentioned total power command value Pt, the command unit 394 forcibly sets the discharge power command value or charge power command value to the total power command value Pt. To do. Here, the reason why the information stored in the command value storage unit 3954 is set to "0" when the calculated discharge power command value or the charge power command value is negative is to prevent the acceleration of battery deterioration. When the information stored in the command value storage unit 3954 is not set to "0", the operation is such that one storage battery is discharged and the other storage battery is charged, so that the deterioration of the storage battery is accelerated.
　容量記憶部３９５２は、蓄電池２１、２２それぞれの定格容量を示す容量情報を記憶する。指令値記憶部３９５４は、指令部３９４により算出された放電電力指令値または充電電力指令値を示す情報を記憶する。 The capacity storage unit 3952 stores capacity information indicating the rated capacity of each of the storage batteries 21 and 22. The command value storage unit 3954 stores information indicating the discharge power command value or the charge power command value calculated by the command unit 394.
　基準指令値記憶部３９５３は、前述の式（１）および式（２）における係数Ｋ１と、総電力指令値Ｐｔを示す総電力指令値情報と、オフセット電力指令値ｋ２を示すオフセット電力指令値情報と、を記憶する。ここで、基準指令値記憶部３９５３は、１種類の総電力指令値情報と、正負の２種類のオフセット電力指令値ｋ２を示すオフセット電力指令値情報と、を記憶する。指令部３９４は、下記式（１）および式（２）に示す関係式を用いて、放電電力指令値または充電電力指令値を算出する際、容量記憶部３９５２が記憶する容量情報と基準指令値記憶部３９５３が記憶する総電力指令値情報およびオフセット電力指令値情報とを参照する。 The reference command value storage unit 3953 has the coefficient K1 in the above equations (1) and (2), the total power command value information indicating the total power command value Pt, and the offset power command value information indicating the offset power command value k2. And remember. Here, the reference command value storage unit 3953 stores one type of total power command value information and offset power command value information indicating two types of positive and negative offset power command values k2. The command unit 394 uses the relational expressions shown in the following equations (1) and (2) to calculate the discharge power command value or the charge power command value, and the capacity information and the reference command value stored in the capacity storage unit 3952. The total power command value information and the offset power command value information stored in the storage unit 3953 are referred to.
　次に、本実施の形態に係る制御回路３９の指令部３９４が実行する電力指令値設定処理について、図４を参照しながら説明する。この電力指令値設定処理は、パワーコンディショナ３が起動したことを契機として開始される。なお、制御回路３９は、この電力指令値設定処理の実行と並行して、ＰＶコンバータ３１の動作を制御する処理、インバータ３２の動作を制御する処理およびＤＣ－ＤＣコンバータ３３１、３３２の動作を制御する処理を実行する。 Next, the power command value setting process executed by the command unit 394 of the control circuit 39 according to the present embodiment will be described with reference to FIG. This power command value setting process is started when the power conditioner 3 is activated. The control circuit 39 controls the operation of the PV converter 31, the operation of the inverter 32, and the operation of the DC- DC converters 331 and 332 in parallel with the execution of the power command value setting process. Execute the process to be performed.
　まず、指令部３９４は、電圧計測部３３１１から入力される計測信号から、蓄電池２１、２２の出力電圧の電圧値を取得する（ステップＳ１０１）。次に、指令部３９４は、取得した電圧値とＳＯＣ相関テーブルとに基づいて、蓄電池２１、２２のＳＯＣ値を算出する（ステップＳ１０２）。 First, the command unit 394 acquires the voltage value of the output voltage of the storage batteries 21 and 22 from the measurement signal input from the voltage measurement unit 3311 (step S101). Next, the command unit 394 calculates the SOC values of the storage batteries 21 and 22 based on the acquired voltage value and the SOC correlation table (step S102).
　続いて、指令部３９４は、ＤＣ―ＤＣコンバータ３３１、３３２が充電モードで動作しているか否かを判定する（ステップＳ１０３）。指令部３９４が、ＤＣ―ＤＣコンバータ３３１、３３２が充電モードで動作していると判定したとする（ステップＳ１０３：Ｙｅｓ）。この場合、指令部３９４は、基準指令値記憶部３９５３が記憶するオフセット電力指令値情報を参照して、前述の式（１）および式（２）におけるオフセット電力指令値ｋ２として負のオフセット電力指令値ｋ２を採用する（ステップＳ１０４）。一方、指令部３９４が、ＤＣ―ＤＣコンバータ３９３１、３９３２が放電モードで動作していると判定したとする（ステップＳ１０３：Ｎｏ）。この場合、指令部３９４は、基準指令値記憶部３９５３が記憶するオフセット電力指令値情報を参照して、前述の式（１）および式（２）におけるオフセット電力指令値ｋ２として正のオフセット電力指令値ｋ２を採用する（ステップＳ１０５）。 Subsequently, the command unit 394 determines whether or not the DC- DC converters 331 and 332 are operating in the charging mode (step S103). It is assumed that the command unit 394 determines that the DC- DC converters 331 and 332 are operating in the charging mode (step S103: Yes). In this case, the command unit 394 refers to the offset power command value information stored in the reference command value storage unit 3953, and sets a negative offset power command as the offset power command value k2 in the above equations (1) and (2). The value k2 is adopted (step S104). On the other hand, it is assumed that the command unit 394 determines that the DC- DC converters 3931 and 3932 are operating in the discharge mode (step S103: No). In this case, the command unit 394 refers to the offset power command value information stored in the reference command value storage unit 3953, and sets a positive offset power command as the offset power command value k2 in the above equations (1) and (2). The value k2 is adopted (step S105).
　その後、指令部３９４は、蓄電池２１、２２それぞれの定格容量と、係数Ｋ１と、前述の総電力指令値Ｐｔと、前述のステップＳ１０４またはステップＳ１０５で採用したオフセット電力指令値ｋ２と、前述の式（１）および式（２）の関係式とを用いて、放電電力指令値または充電電力指令値を算出するが、簡略化のために、以降ではＫ１＝１として説明する。そして、指令部３９４は、算出した放電電力指令値または充電電力指令値を示す情報を指令値記憶部３９５４に記憶させる（ステップＳ１０６）。ここで、指令部３９４は、容量記憶部３９５２が記憶する蓄電池２１、２２それぞれの定格容量を示す容量情報を参照して、蓄電池２１、２２それぞれの定格容量を取得する。 After that, the command unit 394 uses the rated capacities of the storage batteries 21 and 22, the coefficient K1, the above-mentioned total power command value Pt, the offset power command value k2 adopted in the above-mentioned step S104 or step S105, and the above-mentioned formula. The discharge power command value or the charge power command value is calculated by using the relational expressions of (1) and (2), but for the sake of simplicity, K1 = 1 will be described below. Then, the command unit 394 stores the calculated discharge power command value or information indicating the charge power command value in the command value storage unit 3954 (step S106). Here, the command unit 394 acquires the rated capacity of each of the storage batteries 21 and 22 by referring to the capacity information indicating the rated capacity of each of the storage batteries 21 and 22 stored in the capacity storage unit 3952.
　次に、指令部３９４は、算出した放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢのうちのいずれかが０未満であるか否かを判定する（ステップＳ１０７）。指令部３９４は、算出した放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢが０以上であると判定すると（ステップＳ１０７：Ｎｏ）、そのまま後述のステップＳ１０９の処理を実行する。一方、指令部３９４が、算出した放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢのいずれかが０未満、即ち、負であると判定したとする（ステップＳ１０７：Ｙｅｓ）。この場合、指令部３９４は、指令値記憶部３９４５が記憶する、負である放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢを示す情報を、「０」を示す情報に更新する（ステップＳ１０８）。即ち、指令部３９４は、算出した放電電力指令値または前記充電電力指令値が負である場合、放電電力指令値または前記充電電力指令値をゼロに設定する。 Next, the command unit 394 determines whether or not any of the calculated discharge power command value or charge power command value PtA and PtB is less than 0 (step S107). When the command unit 394 determines that the calculated discharge power command value or charge power command value PtA or PtB is 0 or more (step S107: No), the command unit 394 directly executes the process of step S109 described later. On the other hand, it is assumed that the command unit 394 determines that either the calculated discharge power command value or the charge power command value PtA or PtB is less than 0, that is, negative (step S107: Yes). In this case, the command unit 394 updates the information indicating the negative discharge power command value or the charge power command value PtA, PtB stored in the command value storage unit 3945 to the information indicating "0" (step S108). .. That is, when the calculated discharge power command value or the charge power command value is negative, the command unit 394 sets the discharge power command value or the charge power command value to zero.
　続いて、指令部３９４は、算出した放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢのうちのいずれかが総電力指令値Ｐｔよりも大きいか否かを判定する（ステップＳ１０９）。指令部３９４は、算出した放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢが総電力指令値Ｐｔ以下であると判定すると（ステップＳ１０９：Ｎｏ）、そのまま後述のステップＳ１１１の処理を実行する。一方、指令部３９４が、算出した放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢのいずれかが総電力指令値Ｐｔよりも大きいと判定したとする（ステップＳ１０７：Ｙｅｓ）。この場合、指令部３９４は、指令値記憶部３９４５が記憶する、総電力指令値Ｐｔよりも大きい放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢを示す情報を、総電力指令値Ｐｔを示す情報に更新する（ステップＳ１１０）。即ち、指令部３９４は、算出した放電電力指令値または充電電力指令値が前述の総電力指令値Ｐｔを超える場合、放電電力指令値または充電電力指令値を総電力指令値Ｐｔに設定する。 Subsequently, the command unit 394 determines whether or not any of the calculated discharge power command value or charge power command value PtA or PtB is larger than the total power command value Pt (step S109). When the command unit 394 determines that the calculated discharge power command value or charge power command value PtA or PtB is equal to or less than the total power command value Pt (step S109: No), the command unit 394 directly executes the process of step S111 described later. On the other hand, it is assumed that the command unit 394 determines that either the calculated discharge power command value or the charge power command value PtA or PtB is larger than the total power command value Pt (step S107: Yes). In this case, the command unit 394 stores information indicating the discharge power command value or the charge power command value PtA, PtB, which is larger than the total power command value Pt, stored in the command value storage unit 3945, and information indicating the total power command value Pt. Update to (step S110). That is, when the calculated discharge power command value or charge power command value exceeds the above-mentioned total power command value Pt, the command unit 394 sets the discharge power command value or charge power command value to the total power command value Pt.
　その後、指令部３９４は、指令値記憶部３９４５が記憶する放電電力指令値または充電電力指令値ＰｔＡ、ＰｔＢを示す指令値情報を、ＤＣ－ＤＣコンバータ制御部３９３１、３９３２へ出力する（ステップＳ１１１）。このとき、ＤＣ－ＤＣコンバータ制御部３９３１、３９３２は、指令部３９４から出力される放電電力指令値または充電電力指令値を示す指令値情報に基づいて、ＤＣ―ＤＣコンバータ３３１、３３２を各別に制御する。次に、再びステップＳ１０１の処理が実行される。 After that, the command unit 394 outputs command value information indicating the discharge power command value or the charge power command values PtA and PtB stored in the command value storage unit 3945 to the DC-DC converter control units 3931 and 3932 (step S111). .. At this time, the DC-DC converter control units 3931 and 3932 separately control the DC- DC converters 331 and 332 based on the discharge power command value or the charge power command value indicating the discharge power command value output from the command unit 394. To do. Next, the process of step S101 is executed again.
　次に、本実施の形態に係るパワーコンディショナ３の動作について、比較例に係るパワーコンディショナの動作と比較しながら説明する。比較例に係るパワーコンディショナは、本実施の形態に係るパワーコンディショナ３と同様の構成を有し、指令部３９４の放電電力指令値または充電電力指令値の算出方法のみが本実施の形態と相違する。比較例に係る指令部３９４は、下記式（３）および式（４）に示す関係式を用いて、放電電力指令値または充電電力指令値を算出する。
ＰｔＡ＝［ＰＡ×（１－Ｓａ）／｛（ＰＡ×（１－Ｓａ）＋ＰＢ×（１－Ｓｂ）｝］×２　　　・・・式（３）
ＰｔＢ＝［ＰＢ×（１－Ｓｂ）／｛（ＰＡ×（１－Ｓａ）＋ＰＢ×（１－Ｓｂ）｝］×２　　　・・・式（４）
　ここで、ＰｔＡ、ＰｔＢ、ＰＡ、ＰＢ、Ｓａ、Ｓｂは、それぞれ、前述の式（１）および式（２）におけるそれらと同様である。 Next, the operation of the power conditioner 3 according to the present embodiment will be described while comparing with the operation of the power conditioner according to the comparative example. The power conditioner according to the comparative example has the same configuration as the power conditioner 3 according to the present embodiment, and only the calculation method of the discharge power command value or the charge power command value of the command unit 394 is the same as that of the present embodiment. It's different. The command unit 394 according to the comparative example calculates the discharge power command value or the charge power command value by using the relational expressions shown in the following formulas (3) and (4).
PtA = [PA × (1-Sa) / {(PA × (1-Sa) + PB × (1-Sb)}] × 2 ・ ・ ・ Equation (3)
PtB = [PB × (1-Sb) / {(PA × (1-Sa) + PB × (1-Sb)}] × 2 ・ ・ ・ Equation (4)
Here, PtA, PtB, PA, PB, Sa, and Sb are the same as those in the above formulas (1) and (2), respectively.
　例えば蓄電池２１の定格容量を４［ｋＷｈ］、蓄電池２２の定格容量を２［ｋＷｈ］であり、蓄電池２１のＳＯＣ値が「０．５（５０％）」、蓄電池２２のＳＯＣ値が「０．４（４０％）」であるとする。そして、比較例に係る指令部３９４が、ＤＣ－ＤＣコンバータ３３１、３３２を充電モードで動作させるとともに、前述の総電力指令値Ｐｔを２［ｋＷ］に設定したとする。この場合、指令部３９４は、式（３）に示す関係式を用いて、蓄電池２１への充電電力指令値を、［４×（１－０．５）／｛４×（１－０．５）＋２×（１－０．４）｝］×２＝１．２５［ｋＷ］と算出する。また、指令部３９４は、式（４）に示す関係式を用いて、蓄電池２２への充電電力指令値を、［２×（１－０．４）／｛４×（１－０．５）＋２×（１－０．４）｝］×２＝０．７５［ｋＷ］と算出する。このように、蓄電池２１、２２の定格容量の比が、２：１であるにも関わらず、ＳＯＣ値の違いを考慮した式（３）および式（４）に示す関係式を用いて算出される蓄電池２１、２２に対応する充電電力指令値の比は、５：３となる。 For example, the rated capacity of the storage battery 21 is 4 [kWh], the rated capacity of the storage battery 22 is 2 [kWh], the SOC value of the storage battery 21 is "0.5 (50%)", and the SOC value of the storage battery 22 is "0. 4 (40%) ”. Then, it is assumed that the command unit 394 according to the comparative example operates the DC- DC converters 331 and 332 in the charging mode and sets the above-mentioned total power command value Pt to 2 [kW]. In this case, the command unit 394 sets the charge power command value to the storage battery 21 to [4 × (1-0.5) / {4 × (1-0.5) by using the relational expression shown in the equation (3). ) + 2 × (1-0.4)}] × 2 = 1.25 [kW]. Further, the command unit 394 sets the charge power command value to the storage battery 22 to [2 × (1-0.4) / {4 × (1-0.5)) by using the relational expression shown in the equation (4). It is calculated as +2 × (1-0.4)}] × 2 = 0.75 [kW]. In this way, even though the ratio of the rated capacities of the storage batteries 21 and 22 is 2: 1, it is calculated using the relational expressions shown in the equations (3) and (4) in consideration of the difference in SOC values. The ratio of the charging power command values corresponding to the storage batteries 21 and 22 is 5: 3.
　ここで、比較例に係るパワーコンディショナについて、ＤＣ－ＤＣコンバータ３３１、３３２を充電モードで動作を開始させた後における蓄電池２１、２２のＳＯＣ値の時間推移の一例を図５に示す。図５の曲線Ｓ９１、Ｓ９２に示すように、蓄電池２１、２２のＳＯＣ値の差分値は、ＤＣ－ＤＣコンバータ３３１、３３２が充電モードで動作を開始してから１０分程度の間、経時的に減少する。但し、１０分以上経過した時点においては、蓄電池２１、２２のＳＯＣ値の差分値はほとんど一定であることが判る。このため、蓄電池２１、２２のＳＯＣ値を等しくすることができない。また、蓄電池２１、２２のＳＯＣ値の差分値が比較的大きい場合、例えば、蓄電池２１のＳＯＣ値が０．９（９０％）であり、蓄電池２２のＳＯＣ値が０．１（１０％）である場合、蓄電池２１、２２のＳＯＣ値の差分値をある程度小さくするまでに要する時間が長くなってしまう虞がある。 Here, regarding the power conditioner according to the comparative example, FIG. 5 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 after the DC- DC converters 331 and 332 are started to operate in the charging mode. As shown in the curves S91 and S92 of FIG. 5, the difference value of the SOC values of the storage batteries 21 and 22 is measured over time for about 10 minutes after the DC- DC converters 331 and 332 start operating in the charging mode. Decrease. However, when 10 minutes or more have passed, it can be seen that the difference value of the SOC values of the storage batteries 21 and 22 is almost constant. Therefore, the SOC values of the storage batteries 21 and 22 cannot be made equal. When the difference value of the SOC values of the storage batteries 21 and 22 is relatively large, for example, the SOC value of the storage battery 21 is 0.9 (90%) and the SOC value of the storage battery 22 is 0.1 (10%). In some cases, the time required to reduce the difference value of the SOC values of the storage batteries 21 and 22 to some extent may become long.
　これに対して、本実施の形態に係るパワーコンディショナ３では、指令部３９４が、前述の式（１）および式（２）に示す関係式を用いて、放電電力指令値または充電電力指令値を算出する。例えば蓄電池２１の定格容量を４［ｋＷｈ］、蓄電池２２の定格容量を２［ｋＷｈ］であり、蓄電池２１のＳＯＣ値が「０．５（５０％）」、蓄電池２２のＳＯＣ値が「０（０％）」であるとする。そして、指令部３９４が、ＤＣ－ＤＣコンバータ３３１、３３２を充電モードで動作させるとともに、前述の総電力指令値Ｐｔを２［ｋＷ］に設定したとする。また、オフセット電力指令値が、０．１［ｋＷ］に設定されているとする。この場合、指令部３９４は、式（１）に示す関係式を用いて、蓄電池２１に対応する充電電力指令値を、｛４／（２＋４）｝×２－（５０－０）×０．１＝－３．６６［ｋＷ］と算出する。また、指令部３９４は、式（２）に示す関係式を用いて、蓄電池２２に対応する充電電力指令値を、｛２／（２＋４）｝×２＋（５０－０）×０．１＝５．６６［ｋＷ］と算出される。そして、指令部３９４は、算出した蓄電池２１の充電電力指令値が０未満であるため、蓄電池２１の充電電力指令値を「０」に更新する。これにより、指令部３９４は、蓄電池２１を充電せずに、蓄電池２２のみに２［ｋＷ］充電させるための指令値情報を、ＤＣ－ＤＣコンバータ制御部３９３１、３９３２へ出力する。 On the other hand, in the power conditioner 3 according to the present embodiment, the command unit 394 uses the relational expressions shown in the above equations (1) and (2) to generate a discharge power command value or a charge power command value. Is calculated. For example, the rated capacity of the storage battery 21 is 4 [kWh], the rated capacity of the storage battery 22 is 2 [kWh], the SOC value of the storage battery 21 is "0.5 (50%)", and the SOC value of the storage battery 22 is "0 (" 0%) ”. Then, it is assumed that the command unit 394 operates the DC- DC converters 331 and 332 in the charging mode and sets the above-mentioned total power command value Pt to 2 [kW]. Further, it is assumed that the offset power command value is set to 0.1 [kW]. In this case, the command unit 394 sets the charging power command value corresponding to the storage battery 21 to {4 / (2 + 4)} × 2- (50-0) × 0.1 by using the relational expression shown in the equation (1). = -3.66 [kW] is calculated. Further, the command unit 394 sets the charging power command value corresponding to the storage battery 22 to {2 / (2 + 4)} × 2 + (50-0) × 0.1 = 5 by using the relational expression shown in the equation (2). It is calculated as .66 [kW]. Then, since the calculated charging power command value of the storage battery 21 is less than 0, the command unit 394 updates the charging power command value of the storage battery 21 to "0". As a result, the command unit 394 outputs command value information for charging only the storage battery 22 by 2 [kW] without charging the storage battery 21 to the DC-DC converter control units 3931 and 3932.
　つまり、指令部３９４は、ＤＣ―ＤＣコンバータ３３１、３３２を充電モードで動作させる場合、蓄電池２１のＳＯＣ値が蓄電池２２のＳＯＣ値よりも大きいとき、蓄電池２１に対応する双方向ＤＣ―ＤＣコンバータ３３１についての充電電力指令値を「０」に設定して蓄電池２１を充電させない。一方、指令部３９４は、蓄電池２２に対応する双方向ＤＣ―ＤＣコンバータ３３２についての充電電力指令値を「０」よりも大きい値に設定して蓄電池２２を充電させる。言い換えると、指令部３９４は、ＤＣ―ＤＣコンバータ３３１、３３２を充電モードで動作させる場合、蓄電池２１のＳＯＣ値が蓄電池２２のＳＯＣ値よりも大きいとき、蓄電池２１に対応するＤＣ－ＤＣコンバータ３３１についての時間に対するＳＯＣ値の変動の傾きを、蓄電池２２に対応するＤＣ－ＤＣコンバータ３３２についての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように充電電力指令値を算出する。なお、ＤＣ－ＤＣコンバータ３３１、３３２それぞれについての充電電力指令値は上記に限定されない。 That is, when the command unit 394 operates the DC- DC converters 331 and 332 in the charging mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the bidirectional DC-DC converter 331 corresponding to the storage battery 21 The charging power command value for is set to "0" so that the storage battery 21 is not charged. On the other hand, the command unit 394 sets the charging power command value for the bidirectional DC-DC converter 332 corresponding to the storage battery 22 to a value larger than "0" to charge the storage battery 22. In other words, when the command unit 394 operates the DC- DC converters 331 and 332 in the charging mode and the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the command unit 394 relates to the DC-DC converter 331 corresponding to the storage battery 21. The charging power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is smaller than the gradient of the SOC value fluctuation with respect to time for the DC-DC converter 332 corresponding to the storage battery 22. The charging power command value for each of the DC- DC converters 331 and 332 is not limited to the above.
　ここで、本実施の形態に係るパワーコンディショナ３について、ＤＣ－ＤＣコンバータ３３１、３３２を充電モードで動作を開始させた後における蓄電池２１、２２のＳＯＣ値の時間推移の一例を図６に示す。図６の曲線Ｓ１１に示すように、ＤＣ－ＤＣコンバータ３３１、３３２が充電モードで動作を開始してから２０分程度の間、蓄電池２１のＳＯＣ値は略「０．５（５０％）」で維持される。一方、図６の曲線Ｓ１２に示すように、蓄電池２２のＳＯＣ値は上昇し続ける。これに伴い、蓄電池２１、２２のＳＯＣ値の差分値が減少していく。そして、ＤＣ－ＤＣコンバータ３３１、３３２が充電モードで動作を開始してから２０分以上経過すると、蓄電池２１への充電が開始され、蓄電池２１のＳＯＣ値も漸増していく。一方、蓄電池２２のＳＯＣ値の上昇率も緩やかになる。ここで、蓄電池２１、２２のＳＯＣ値は、前述の式（１）および式（２）におけるオフセット電力指令値に起因して最終的に等しくなる。 Here, FIG. 6 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 after the DC- DC converters 331 and 332 are started to operate in the charging mode for the power conditioner 3 according to the present embodiment. .. As shown in the curve S11 of FIG. 6, the SOC value of the storage battery 21 is approximately "0.5 (50%)" for about 20 minutes after the DC- DC converters 331 and 332 start operating in the charging mode. Be maintained. On the other hand, as shown in the curve S12 of FIG. 6, the SOC value of the storage battery 22 continues to increase. Along with this, the difference value of the SOC values of the storage batteries 21 and 22 decreases. Then, when 20 minutes or more have passed since the DC- DC converters 331 and 332 started operating in the charging mode, charging of the storage battery 21 is started, and the SOC value of the storage battery 21 is gradually increased. On the other hand, the rate of increase in the SOC value of the storage battery 22 also slows down. Here, the SOC values of the storage batteries 21 and 22 are finally equal due to the offset power command values in the above equations (1) and (2).
　ここで、図６における、蓄電池２１、２２のＳＯＣ値が最終的に等しくなった部分（図６の破線Ａ１で囲んだ部分）を拡大した図を図７に示す。指令部３９４は、ＤＣ―ＤＣコンバータ３３１、３３２を充電モードで動作させる場合、蓄電池２１のＳＯＣ値が蓄電池２２のＳＯＣ値よりも大きいとき、蓄電池２１に対応するＤＣ－ＤＣコンバータ３３１についての時間に対するＳＯＣ値の変動の傾きが、蓄電池２２に対応するＤＣ－ＤＣコンバータ３３２についての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように充電電力指令値を算出する。このため、図７に示すように、実際には蓄電池２１に対応する曲線Ｓ１１と蓄電池２２に対応する曲線Ｓ１２とは、完全に重なっている訳ではなく、常に大小関係が交互に入れ替わるような形で収束していく。即ち、充電開始当初は、オフセット電力指令値によって、蓄電池２１に対応する曲線Ｓ１１の傾きが緩やかであり、蓄電池２２に対応する曲線Ｓ１２の傾きが比較的急峻である。これにより、蓄電池２１に対応する曲線Ｓ１１と蓄電池２２に対応する曲線Ｓ１２とがあるＳＯＣ値において互いに交わり、その後、曲線Ｓ１１、Ｓ１２の大小関係が逆転する。そして、曲線Ｓ１１、Ｓ１２の大小関係が逆転した直後は、指令部３９４が、蓄電池２１に対応する曲線Ｓ１１が急峻になるとともに、蓄電池２２に対応する曲線Ｓ１２が比較的緩やかになるように充電指令値を設定するので、曲線Ｓ１１、Ｓ１２の大小関係が再び逆転する。そして、これを繰り返すうちに、蓄電池２１に対応する曲線Ｓ１１と蓄電池２２に対応する曲線Ｓ１２とが、マクロ的に見ると重なったように見える状態で収束する。このことを、蓄電池２１、２２のＳＯＣ値が「等しくなる」としている。この現象は、充電モードでの動作時に限らず、後述の放電モードでの動作時においても同様である。 Here, FIG. 7 shows an enlarged view of the portion of the storage batteries 21 and 22 in FIG. 6 in which the SOC values are finally equalized (the portion surrounded by the broken line A1 in FIG. 6). When the command unit 394 operates the DC- DC converters 331 and 332 in the charging mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the command unit 394 relates to the time for the DC-DC converter 331 corresponding to the storage battery 21. The charging power command value is calculated so that the slope of the fluctuation of the SOC value is smaller than the slope of the fluctuation of the SOC value with respect to time for the DC-DC converter 332 corresponding to the storage battery 22. Therefore, as shown in FIG. 7, the curve S11 corresponding to the storage battery 21 and the curve S12 corresponding to the storage battery 22 are not completely overlapped with each other, and the magnitude relations are always alternately alternated. Converges with. That is, at the beginning of charging, the slope of the curve S11 corresponding to the storage battery 21 is gentle and the slope of the curve S12 corresponding to the storage battery 22 is relatively steep depending on the offset power command value. As a result, the curve S11 corresponding to the storage battery 21 and the curve S12 corresponding to the storage battery 22 intersect each other at a certain SOC value, and then the magnitude relationship of the curves S11 and S12 is reversed. Immediately after the magnitude relationship between the curves S11 and S12 is reversed, the command unit 394 gives a charging command so that the curve S11 corresponding to the storage battery 21 becomes steep and the curve S12 corresponding to the storage battery 22 becomes relatively gentle. Since the value is set, the magnitude relationship of the curves S11 and S12 is reversed again. Then, as this process is repeated, the curve S11 corresponding to the storage battery 21 and the curve S12 corresponding to the storage battery 22 converge in a state in which they appear to overlap when viewed macroscopically. This means that the SOC values of the storage batteries 21 and 22 are "equal". This phenomenon is the same not only when operating in the charging mode but also when operating in the discharging mode described later.
　また、例えば蓄電池２１の定格容量を４［ｋＷｈ］、蓄電池２２の定格容量を２［ｋＷｈ］であり、蓄電池２１のＳＯＣ値が「１．０（１００％）」、蓄電池２２のＳＯＣ値が「０．５（５０％）」であるとする。そして、指令部３９４が、ＤＣ－ＤＣコンバータ３３１、３３２を放電モードで動作させるとともに、前述の総電力指令値Ｐｔを２［ｋＷ］に設定したとする。また、オフセット電力指令値が、０．１［ｋＷ］に設定されているとする。この場合、指令部３９４は、式（１）に示す関係式を用いて、蓄電池２１に対応する放電電力指令値を、｛４／（２＋４）｝×２＋（１００－５０）×０．１＝６．３３［ｋＷ］と算出する。また、指令部３９４は、式（２）に示す関係式を用いて、蓄電池２２に対応する放電電力指令値を、｛２／（２＋４）｝×２－（１００－５０）×０．１＝－４．３３［ｋＷ］と算出する。そして、指令部３９４は、算出した蓄電池２２の放電電力指令値が０未満であるため、蓄電池２２に対応する放電電力指令値を「０」に更新する。これにより、指令部３９４は、蓄電池２２を放電させず、蓄電池２１のみに２［ｋＷ］を放電させるための指令値情報を、ＤＣ－ＤＣコンバータ制御部３９３１、３９３２へ出力する。 Further, for example, the rated capacity of the storage battery 21 is 4 [kWh], the rated capacity of the storage battery 22 is 2 [kWh], the SOC value of the storage battery 21 is "1.0 (100%)", and the SOC value of the storage battery 22 is "1.0 (100%)". It is assumed that it is "0.5 (50%)". Then, it is assumed that the command unit 394 operates the DC- DC converters 331 and 332 in the discharge mode and sets the above-mentioned total power command value Pt to 2 [kW]. Further, it is assumed that the offset power command value is set to 0.1 [kW]. In this case, the command unit 394 sets the discharge power command value corresponding to the storage battery 21 to {4 / (2 + 4)} × 2 + (100-50) × 0.1 = by using the relational expression shown in the equation (1). It is calculated as 6.33 [kW]. Further, the command unit 394 sets the discharge power command value corresponding to the storage battery 22 to {2 / (2 + 4)} × 2- (100-50) × 0.1 = by using the relational expression shown in the equation (2). -4.33 [kW] is calculated. Then, since the calculated discharge power command value of the storage battery 22 is less than 0, the command unit 394 updates the discharge power command value corresponding to the storage battery 22 to “0”. As a result, the command unit 394 outputs command value information for discharging 2 [kW] only to the storage battery 21 without discharging the storage battery 22 to the DC-DC converter control units 3931 and 3932.
　つまり、指令部３９４は、ＤＣ―ＤＣコンバータ３３１、３３２を放電モードで動作させる場合、蓄電池２１のＳＯＣ値が蓄電池２２のＳＯＣ値よりも大きいとき、蓄電池２１に対応するＤＣ―ＤＣコンバータ３３１についての放電電力指令値を「０」よりも大きい値に設定して蓄電池２１を放電させる。一方、指令部３９４は、蓄電池２２に対応するＤＣ―ＤＣコンバータ３３２についての放電電力指令値を「０」に設定して蓄電池２２を放電させない。言い換えると、指令部３９４は、ＤＣ－ＤＣコンバータ３３１、３３２を放電モードで動作させる場合、蓄電池２１のＳＯＣ値が蓄電池２２のＳＯＣ値よりも大きいとき、蓄電池２１に対応するＤＣ－ＤＣコンバータ３３１についての時間に対するＳＯＣ値の変動の傾きを、蓄電池２２に対応するＤＣ－ＤＣコンバータ３３２についての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように放電電力指令値を算出する。なお、ＤＣ－ＤＣコンバータ３３１、３３２についての放電電力指令値は上記に限定されない。 That is, when the command unit 394 operates the DC- DC converters 331 and 332 in the discharge mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the command unit 394 relates to the DC-DC converter 331 corresponding to the storage battery 21. The discharge power command value is set to a value larger than "0" to discharge the storage battery 21. On the other hand, the command unit 394 does not discharge the storage battery 22 by setting the discharge power command value for the DC-DC converter 332 corresponding to the storage battery 22 to “0”. In other words, when the command unit 394 operates the DC- DC converters 331 and 332 in the discharge mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the DC-DC converter 331 corresponding to the storage battery 21 The discharge power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is larger than the gradient of the SOC value fluctuation with respect to time for the DC-DC converter 332 corresponding to the storage battery 22. The discharge power command values for the DC- DC converters 331 and 332 are not limited to the above.
　ここで、本実施の形態に係るパワーコンディショナ３について、ＤＣ－ＤＣコンバータ３３１、３３２を放電モードで動作を開始させた後における蓄電池２１、２２のＳＯＣ値の時間推移の一例を図８に示す。図８の曲線Ｓ２２に示すように、ＤＣ－ＤＣコンバータ３３１、３３２が放電モードで動作を開始してから４５分程度の間、蓄電池２２のＳＯＣ値は略「５０％（０．５）」で維持される。一方、図８の曲線Ｓ２１に示すように、蓄電池２１のＳＯＣ値は下降し続ける。これに伴い、蓄電池２１、２２のＳＯＣ値の差分値が減少していく。そして、ＤＣ－ＤＣコンバータ３３１、３３２が放電モードで動作を開始してから４５分以上経過すると、蓄電池２２の放電が開始され、蓄電池２２のＳＯＣ値も漸減していく。一方、蓄電池２２のＳＯＣ値の下降率も緩やかになる。ここで、蓄電池２１、２２のＳＯＣ値は、前述の式（１）および式（２）におけるオフセット電力指令値に起因して最終的に等しくなる。 Here, FIG. 8 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 after the DC- DC converters 331 and 332 are started to operate in the discharge mode for the power conditioner 3 according to the present embodiment. .. As shown in the curve S22 of FIG. 8, the SOC value of the storage battery 22 is approximately "50% (0.5)" for about 45 minutes after the DC- DC converters 331 and 332 start operating in the discharge mode. Be maintained. On the other hand, as shown in the curve S21 of FIG. 8, the SOC value of the storage battery 21 continues to decrease. Along with this, the difference value of the SOC values of the storage batteries 21 and 22 decreases. Then, when 45 minutes or more have passed since the DC- DC converters 331 and 332 started operation in the discharge mode, the storage battery 22 started to be discharged, and the SOC value of the storage battery 22 gradually decreased. On the other hand, the rate of decrease in the SOC value of the storage battery 22 also becomes gradual. Here, the SOC values of the storage batteries 21 and 22 are finally equal due to the offset power command values in the above equations (1) and (2).
　ここで、図８における、蓄電池２１、２２のＳＯＣ値が最終的に等しくなった部分（図６の破線Ａ２で囲んだ部分）を拡大した図を図９に示す。指令部３９４は、ＤＣ―ＤＣコンバータ３３１、３３２を放電モードで動作させる場合、蓄電池２１のＳＯＣ値が蓄電池２２のＳＯＣ値よりも大きいとき、蓄電池２１に対応するＤＣ－ＤＣコンバータ３３１についての時間に対するＳＯＣ値の変動の傾きの絶対値が、蓄電池２２に対応するＤＣ－ＤＣコンバータ３３２についての時間に対するＳＯＣ値の変動の傾きの絶対値よりも大きい値となるように充電電力指令値を算出する。このため、図９に示すように、実際には蓄電池２１に対応する曲線Ｓ２１と蓄電池２２に対応する曲線Ｓ２２とは、完全に重なっている訳ではなく、常に大小関係が交互に入れ替わるような形で収束していく。即ち、放電開始当初は、オフセット電力指令値により、蓄電池２１に対応する曲線Ｓ２１の傾きが急峻であり、蓄電池２２に対応する曲線Ｓ２２の傾きが比較的緩やかである。これにより、蓄電池２１に対応する曲線Ｓ２１と蓄電池２２に対応する曲線Ｓ２２とがあるＳＯＣ値において互いに交わり、その後、曲線Ｓ２１、Ｓ２２の大小関係が逆転する。そして、曲線Ｓ２１、Ｓ２２の大小関係が逆転した直後は、指令部３９４が、蓄電池２１に対応する曲線Ｓ２１の傾きが緩やかになるとともに、蓄電池２２に対応する曲線Ｓ２２の傾きが比較的急峻になるように充電指令値を設定するので、曲線Ｓ２１、Ｓ２２の大小関係が再び逆転する。そして、これを繰り返すうちに、蓄電池２１に対応する曲線Ｓ２１と蓄電池２２に対応する曲線Ｓ２２とが、マクロ的に見ると重なったように見える状態で収束する。このことを、蓄電池２１、２２のＳＯＣ値が「等しくなる」としている。 Here, FIG. 9 shows an enlarged view of the portion (the portion surrounded by the broken line A2 in FIG. 6) in which the SOC values of the storage batteries 21 and 22 are finally equal in FIG. When the command unit 394 operates the DC- DC converters 331 and 332 in the discharge mode, when the SOC value of the storage battery 21 is larger than the SOC value of the storage battery 22, the command unit 394 relates to the time for the DC-DC converter 331 corresponding to the storage battery 21. The charging power command value is calculated so that the absolute value of the slope of the fluctuation of the SOC value becomes a value larger than the absolute value of the slope of the fluctuation of the SOC value with respect to the time of the DC-DC converter 332 corresponding to the storage battery 22. Therefore, as shown in FIG. 9, the curve S21 corresponding to the storage battery 21 and the curve S22 corresponding to the storage battery 22 are not completely overlapped with each other, and the magnitude relations are always alternately alternated. Converges with. That is, at the beginning of discharge, the slope of the curve S21 corresponding to the storage battery 21 is steep and the slope of the curve S22 corresponding to the storage battery 22 is relatively gentle due to the offset power command value. As a result, the curve S21 corresponding to the storage battery 21 and the curve S22 corresponding to the storage battery 22 intersect each other at a certain SOC value, and then the magnitude relationship of the curves S21 and S22 is reversed. Immediately after the magnitude relationship between the curves S21 and S22 is reversed, the command unit 394 makes the slope of the curve S21 corresponding to the storage battery 21 gentle and the slope of the curve S22 corresponding to the storage battery 22 relatively steep. Since the charging command value is set as described above, the magnitude relationship of the curves S21 and S22 is reversed again. Then, as this process is repeated, the curve S21 corresponding to the storage battery 21 and the curve S22 corresponding to the storage battery 22 converge in a state in which they appear to overlap when viewed macroscopically. This means that the SOC values of the storage batteries 21 and 22 are "equal".
　また、本実施の形態に係るパワーコンディショナ３において、蓄電池２１、２２からの２［ｋＷ］の放電を１０分間行った後、蓄電池２１、２２への２［ｋＷ］の充電と蓄電池２１、２２からの２［ｋＷ］の放電とを、１０分間隔で交互に繰り返したとする。ここで、例えば蓄電池２１の定格容量を４［ｋＷｈ］、蓄電池２２の定格容量を２［ｋＷｈ］であり、蓄電池２１のＳＯＣ値が「１．０（１００％）」、蓄電池２２のＳＯＣ値が「０．５（５０％）」であるとする。この場合の蓄電池２１、２２のＳＯＣ値の時間推移の一例を図１０に示す。図１０の曲線Ｓ３１、Ｓ３２に示すように、ＤＣ－ＤＣコンバータ３３１、３３２が放電モードで動作している期間（例えば開始から１０分後までの間の期間または開始から２０後から３０分後までの間の期間）では、蓄電池２１、２２のＳＯＣ値の時間推移は、前述の図８を用いて説明した時間推移と同様になる。一方、ＤＣ－ＤＣコンバータ３３１、３３２が充電モードで動作している期間（例えば開始から１０後から２０分後までの間の期間）では、蓄電池２１、２２のＳＯＣ値の時間推移は、前述の図６を用いて説明した時間推移と同様になる。この場合でも、蓄電池２１、２２のＳＯＣ値は、前述の式（１）および式（２）におけるオフセット電力指令値に起因して最終的に等しくなる。 Further, in the power conditioner 3 according to the present embodiment, after discharging 2 [kW] from the storage batteries 21 and 22 for 10 minutes, the storage batteries 21 and 22 are charged with 2 [kW] and the storage batteries 21 and 22 are charged. It is assumed that the discharge of 2 [kW] from the above is repeated alternately at intervals of 10 minutes. Here, for example, the rated capacity of the storage battery 21 is 4 [kWh], the rated capacity of the storage battery 22 is 2 [kWh], the SOC value of the storage battery 21 is "1.0 (100%)", and the SOC value of the storage battery 22 is. It is assumed to be "0.5 (50%)". FIG. 10 shows an example of the time transition of the SOC values of the storage batteries 21 and 22 in this case. As shown in the curves S31 and S32 of FIG. 10, the period during which the DC- DC converters 331 and 332 are operating in the discharge mode (for example, a period between the start and 10 minutes or 20 to 30 minutes after the start). During the period), the time transition of the SOC values of the storage batteries 21 and 22 is the same as the time transition described with reference to FIG. 8 described above. On the other hand, during the period when the DC- DC converters 331 and 332 are operating in the charging mode (for example, the period from 10 to 20 minutes after the start), the time transition of the SOC values of the storage batteries 21 and 22 is described above. The time transition is the same as that described with reference to FIG. Even in this case, the SOC values of the storage batteries 21 and 22 are finally equal due to the offset power command values in the above equations (1) and (2).
　このように、本実施の形態に係るパワーコンディショナ３では、オフセット電力指令値の項を含む式（１）および式（２）を用いて、蓄電池２１、２２に対応する充電電力指令値または放電電力指令値を算出する。これにより、蓄電池２１、２２のＳＯＣ値に大きな乖離がある場合であっても迅速かつ確実に蓄電池２１、２２のＳＯＣ値を等しくすることができる。 As described above, in the power conditioner 3 according to the present embodiment, the charging power command value or the discharge corresponding to the storage batteries 21 and 22 is used by using the equations (1) and (2) including the offset power command value term. Calculate the power command value. As a result, even if there is a large deviation in the SOC values of the storage batteries 21 and 22, the SOC values of the storage batteries 21 and 22 can be made equal quickly and surely.
　以上説明したように、本実施の形態に係るパワーコンディショナ３によれば、指令部３９４が、蓄電池２１、２２それぞれの定格容量のそれらの総和に対する比率と、蓄電池２１、２２それぞれのＳＯＣ値の差分値と、に基づいて、ＤＣ―ＤＣコンバータ３３１、３３２それぞれの放電電力指令値または充電電力指令値を算出する。これにより、蓄電池２１、２２それぞれのＳＯＣ値を互いに等しい値にすることができるので、蓄電池２１、２２の全てについて満充電状態から放電終止状態までの全範囲に亘って蓄電池に蓄えられた電気を有効に利用することができる。 As described above, according to the power conditioner 3 according to the present embodiment, the command unit 394 determines the ratio of the rated capacities of the storage batteries 21 and 22 to the total of them and the SOC value of each of the storage batteries 21 and 22. Based on the difference value, the discharge power command value or the charge power command value of each of the DC- DC converters 331 and 332 is calculated. As a result, the SOC values of the storage batteries 21 and 22 can be set to be equal to each other, so that the electricity stored in the storage batteries can be stored in the entire range from the fully charged state to the end-discharged state of all the storage batteries 21 and 22. It can be used effectively.
　ところで、蓄電池２１、２２のＳＯＣ値の差異が大きくなると、例えばＤＣ－ＤＣコンバータ３３１、３３２を充電モードで動作させる場合、例えば蓄電池２１が満充電状態になると、他方の蓄電池２２が充電できなくなるといった事態が生じうる。このような事態を防ぐため、蓄電池２１、２２のＳＯＣ値はなるべく等しい値になるように調整することが好ましい。但し、前述の比較例のように、蓄電池２１、２２それぞれのＳＯＣ値と定格容量とを加味して蓄電値２１、２２への充電電力または蓄電池２１、２２からの放電電力を分配するようにしても蓄電池２１、２２それぞれのＳＯＣ値を等しくすることができない。特に、蓄電池２１、２２の定格容量の差異が大きい場合、蓄電池２１、２２のＳＯＣ値の差異が顕著になる。これに対して、本実施の形態に係るパワーコンディショナでは、前述の式（１）および式（２）に示す関係式のようにオフセット電力指令値に関する項を含む関係式を用いて放電電力指令値または充電電力指令値を算出する。これにより、蓄電池２１、２２のＳＯＣ値を等しくすることができる。分配量がリアルタイムで変わっていくので、２つの線は交わらない。蓄電池を増設した場合、電流容量が異なるため、この傾向が顕著である。ずれたままだと、電池の寿命が縮まってしまう。 By the way, when the difference between the SOC values of the storage batteries 21 and 22 becomes large, for example, when the DC- DC converters 331 and 332 are operated in the charging mode, for example, when the storage battery 21 is fully charged, the other storage battery 22 cannot be charged. Things can happen. In order to prevent such a situation, it is preferable to adjust the SOC values of the storage batteries 21 and 22 so as to be as equal as possible. However, as in the above-mentioned comparative example, the charging power to the storage values 21 and 22 or the discharging power from the storage batteries 21 and 22 is distributed in consideration of the SOC values and the rated capacities of the storage batteries 21 and 22 respectively. However, the SOC values of the storage batteries 21 and 22 cannot be equalized. In particular, when the difference in the rated capacities of the storage batteries 21 and 22 is large, the difference in the SOC values of the storage batteries 21 and 22 becomes remarkable. On the other hand, in the power conditioner according to the present embodiment, the discharge power command is performed by using the relational expression including the term related to the offset power command value as in the relational expression shown in the above equations (1) and (2). Calculate the value or the charge power command value. As a result, the SOC values of the storage batteries 21 and 22 can be made equal. The two lines do not intersect because the amount of distribution changes in real time. This tendency is remarkable when a storage battery is added because the current capacity is different. If it remains misaligned, the battery life will be shortened.
　また、本実施の形態に係る指令部３９４は、算出した放電電力指令値または充電電力指令値が負である場合、放電電力指令値または充電電力指令値を強制的にゼロに設定する。これにより、パワーコンディショナ３の動作期間中において、蓄電池２１、２２が放電する期間の割合または蓄電池２１、２２が充電される期間の割合を低減することができるので、その分、蓄電池２１、２２の劣化を抑制することができる。 Further, when the calculated discharge power command value or charge power command value is negative, the command unit 394 according to the present embodiment forcibly sets the discharge power command value or the charge power command value to zero. As a result, during the operating period of the power conditioner 3, the ratio of the period during which the storage batteries 21 and 22 are discharged or the ratio of the period during which the storage batteries 21 and 22 are charged can be reduced. Deterioration can be suppressed.
　更に、本実施の形態に係る指令部３９４は、算出した放電電力指令値または充電電力指令値が総電力指令値を超える場合、放電電力指令値または充電電力指令値を総電力指令値に設定する。これにより、蓄電池２１、２２の過放電または過充電の発生を抑制することができるので、蓄電池２１、２２の損傷を抑制することができる。 Further, the command unit 394 according to the present embodiment sets the discharge power command value or the charge power command value as the total power command value when the calculated discharge power command value or the charge power command value exceeds the total power command value. .. As a result, the occurrence of over-discharging or over-charging of the storage batteries 21 and 22 can be suppressed, so that damage to the storage batteries 21 and 22 can be suppressed.
　以上、本発明の実施の形態について説明したが、本発明は前述の実施の形態の構成に限定されるものではない。例えば、パワーコンディショナ３が、３つ以上の蓄電池を備えるものであってもよい。ここで、３つ以上の蓄電池それぞれに対応するＤＣ－ＤＣコンバータが放電モードで動作する場合、指令部３９４は、３つ以上の蓄電池それぞれのＳＯＣ値のうち最も低いＳＯＣ値と、それ以外の蓄電池それぞれのＳＯＣ値との差分値にオフセット電力指令値を乗じて得られる値に基づいて、最も高いＳＯＣ値の蓄電池から放電指令値を算出していき、途中で総電力指令値に達すれば、残りの蓄電池は放電させないようにすればよい。一方、充電モードで動作する場合は、３つ以上の蓄電池それぞれのＳＯＣ値のうち最も高いＳＯＣ値と、それ以外の蓄電池それぞれのＳＯＣ値との差分地にオフセット電力指令値を乗じて得られる値に基づいて、最も低いＳＯＣ値の蓄電池から充電指令値を算出していき、途中で総電力指令値に達すれば、残りの蓄電池は充電させないようにすればよい。 Although the embodiments of the present invention have been described above, the present invention is not limited to the configuration of the above-described embodiments. For example, the power conditioner 3 may include three or more storage batteries. Here, when the DC-DC converter corresponding to each of the three or more storage batteries operates in the discharge mode, the command unit 394 has the lowest SOC value among the SOC values of the three or more storage batteries and the other storage batteries. Based on the value obtained by multiplying the difference value from each SOC value by the offset power command value, the discharge command value is calculated from the storage battery with the highest SOC value, and if the total power command value is reached in the middle, the rest. The storage battery should not be discharged. On the other hand, when operating in the charging mode, the value obtained by multiplying the difference between the highest SOC value among the SOC values of each of the three or more storage batteries and the SOC value of each of the other storage batteries by the offset power command value. Based on the above, the charging command value is calculated from the storage battery having the lowest SOC value, and if the total power command value is reached in the middle, the remaining storage batteries may not be charged.
　以上、本発明の実施の形態および変形例について説明したが、本発明はこれらに限定されるものではない。本発明は、実施の形態および変形例が適宜組み合わされたもの、それに適宜変更が加えられたものを含む。 Although the embodiments and modifications of the present invention have been described above, the present invention is not limited thereto. The present invention includes an appropriate combination of embodiments and modifications, and an appropriate modification.
　本出願は、２０１９年６月２１日に出願された日本国特許出願特願２０１９－１１５９２１号に基づく。本明細書中に日本国特許出願特願２０１９－１１５９２１号の明細書、特許請求の範囲および図面全体を参照として取り込むものとする。 This application is based on Japanese Patent Application No. 2019-115921 filed on June 21, 2019. The specification, claims and the entire drawings of Japanese Patent Application No. 2019-115921 shall be incorporated into this specification as a reference.
　本発明は、複数の蓄電池を備えるパワーコンディショナとして好適である。 The present invention is suitable as a power conditioner including a plurality of storage batteries.
１：太陽電池、３：パワーコンディショナ、４：系統電源、２１，２２：蓄電池、３１：ＰＶコンバータ、３２：インバータ、３９：制御回路、３３１，３３２：ＤＣ－ＤＣコンバータ、３９１：ＰＶコンバータ制御部、３９２：インバータ制御部、３９４：指令部、３３１１，３３１２：電圧計測部、３９３１，３９３２：ＤＣ－ＤＣコンバータ制御部、３９５１：ＳＯＣ相関記憶部、３９５２：容量記憶部、３９５３：基準指令値記憶部、３９５４：指令値記憶部、ＢＨ，ＢＬ，ＤＨ，ＤＬ：端子、Ｃ１：コンデンサ、ｋ２：オフセット電力指令値、Ｌ３：ＨＶＤＣバス、Ｌ３３１３：インダクタ、Ｑ１，Ｑ２：スイッチング素子 1: Solar battery, 3: Power conditioner, 4: System power supply, 21,22: Storage battery, 31: PV converter, 32: Inverter, 39: Control circuit, 331, 332: DC-DC converter, 391: PV converter control Unit, 392: Inverter control unit, 394: Command unit, 3311, 3312: Voltage measurement unit, 3931, 3932: DC-DC converter control unit, 3951: SOC correlation storage unit, 3952: Capacitor storage unit, 3953: Reference command value Storage unit, 3954: Command value storage unit, BH, BL, DH, DL: Terminal, C1: Capacitor, k2: Offset power command value, L3: HVDC bus, L3313: Inverter, Q1, Q2: Switching element

Claims (9)

  1. 　複数の蓄電池と、
    　直流バスラインと、
    　前記複数の蓄電池それぞれと前記直流バスラインとの間に１つずつ設けられ、前記複数の蓄電池のいずれか１つから出力される直流電力を変換して前記直流バスラインへ出力することにより前記複数の蓄電池からの放電を実行する放電モードまたは前記直流バスラインから供給される直流電力を変換して前記複数の蓄電池のうちのいずれか１つへ出力することにより前記複数の蓄電池のうちのいずれか１つを充電する充電モードで動作する複数の双方向ＤＣ－ＤＣコンバータと、
    　前記複数の双方向ＤＣ－ＤＣコンバータそれぞれについて、前記放電モードで動作する場合の放電電力指令値または前記充電モードで動作する場合の充電電力指令値を算出し、算出した前記放電電力指令値または前記充電電力指令値を示す指令値情報を出力する指令部と、
    　前記指令部から出力される前記指令値情報に基づいて、前記複数の双方向ＤＣ－ＤＣコンバータを各別に制御するＤＣ－ＤＣコンバータ制御部と、を備え、
    　前記指令部は、前記複数の蓄電池それぞれの容量に対する、前記複数の蓄電池の容量の総和の比率と、前記複数の蓄電池それぞれのＳＯＣ値の差分値と、に基づいて、前記複数の双方向ＤＣ－ＤＣコンバータそれぞれの前記放電電力指令値または前記充電電力指令値を算出する、
    　パワーコンディショナ。     With multiple storage batteries
    DC bus line and
    One is provided between each of the plurality of storage batteries and the DC bus line, and the DC power output from any one of the plurality of storage batteries is converted and output to the DC bus line. One of the plurality of storage batteries by executing the discharge from the storage batteries of the above or by converting the DC power supplied from the DC bus line and outputting it to any one of the plurality of storage batteries. Multiple bidirectional DC-DC converters that operate in charge mode to charge one,
    For each of the plurality of bidirectional DC-DC converters, the discharge power command value when operating in the discharge mode or the charge power command value when operating in the charge mode is calculated, and the calculated discharge power command value or the said A command unit that outputs command value information indicating the charging power command value, and
    A DC-DC converter control unit that separately controls the plurality of bidirectional DC-DC converters based on the command value information output from the command unit is provided.
    The command unit is based on the ratio of the total capacity of the plurality of storage batteries to the capacity of each of the plurality of storage batteries and the difference value of the SOC values of the plurality of storage batteries. Calculate the discharge power command value or the charge power command value of each DC converter.
    Power conditioner.
  2. 　前記複数の蓄電池は、２つの蓄電池であり、
    　前記指令部は、２つの蓄電池それぞれの容量に対する、前記２つの蓄電池の容量の総和の比率に基づいて得られる値と、前記２つの蓄電池それぞれのＳＯＣ値と、に基づいて、前記２つの蓄電池のうちのいずれか一方に対応する双方向ＤＣ－ＤＣコンバータについての前記放電電力指令値または前記充電電力指令値と、前記２つの蓄電池のうちの他方に対応する双方向ＤＣ－ＤＣコンバータについての前記放電電力指令値または前記充電電力指令値と、を算出する、
    　請求項１に記載のパワーコンディショナ。     The plurality of storage batteries are two storage batteries.
    The command unit of the two storage batteries is based on a value obtained based on the ratio of the total capacity of the two storage batteries to the capacity of each of the two storage batteries and the SOC value of each of the two storage batteries. The discharge power command value or the charge power command value for the bidirectional DC-DC converter corresponding to any one of them, and the discharge for the bidirectional DC-DC converter corresponding to the other of the two storage batteries. Calculate the power command value or the charging power command value.
    The power conditioner according to claim 1.
  3. 　前記指令部は、２つの蓄電池のうちのいずれか一方の容量に対する、前記２つの蓄電池の容量の総和である総容量の比率に前記２つの蓄電池の全てからの放電電力または充電電力の指令値である総電力指令値を乗じて得られる値に、前記２つの蓄電池のうちの前記一方の蓄電池のＳＯＣ値から他方の蓄電池のＳＯＣ値を差し引いて得られるＳＯＣ差分値に予め設定されたオフセット電力指令値を乗じて得られる値を加えることにより、前記放電電力指令値または前記充電電力指令値を算出し、前記他方の蓄電池の容量の前記総容量に対する比率に前記総電力指令値を乗じて得られる値から、前記ＳＯＣ差分値に前記オフセット電力指令値を乗じて得られる値を差し引くことにより、前記放電電力指令値または前記充電電力指令値を算出する、
    　請求項２に記載のパワーコンディショナ。     The command unit is the command value of the discharge power or the charge power from all of the two storage batteries to the ratio of the total capacity, which is the sum of the capacities of the two storage batteries, to the capacity of one of the two storage batteries. A preset offset power command set to a value obtained by multiplying a certain total power command value by a SOC difference value obtained by subtracting the SOC value of the other storage battery from the SOC value of the one storage battery of the two storage batteries. By adding a value obtained by multiplying the value, the discharge power command value or the charge power command value is calculated, and the ratio of the capacity of the other storage battery to the total capacity is multiplied by the total power command value. The discharge power command value or the charge power command value is calculated by subtracting the value obtained by multiplying the SOC difference value by the offset power command value from the value.
    The power conditioner according to claim 2.
  4. 　前記指令部は、算出した前記放電電力指令値または前記充電電力指令値が負である場合、前記放電電力指令値または前記充電電力指令値をゼロに設定する、
    　請求項３に記載のパワーコンディショナ。     When the calculated discharge power command value or the charge power command value is negative, the command unit sets the discharge power command value or the charge power command value to zero.
    The power conditioner according to claim 3.
  5. 　前記指令部は、算出した前記放電電力指令値または前記充電電力指令値が前記総電力指令値を超える場合、前記放電電力指令値または前記充電電力指令値を前記総電力指令値に設定する、
    　請求項３に記載のパワーコンディショナ。     When the calculated discharge power command value or the charge power command value exceeds the total power command value, the command unit sets the discharge power command value or the charge power command value to the total power command value.
    The power conditioner according to claim 3.
  6. 　前記複数の蓄電池それぞれの出力電圧を計測する電圧計測部を更に備え、
    　前記指令部は、前記電圧計測部により計測された前記複数の蓄電池それぞれの出力電圧に基づいて、前記複数の蓄電池それぞれのＳＯＣ値を算出し、
    　前記オフセット電力指令値は、前記電圧計測部による前記複数の蓄電池それぞれの出力電力の計測誤差に基づいて決定される、
    　請求項３から５のいずれか１項に記載のパワーコンディショナ。     A voltage measuring unit for measuring the output voltage of each of the plurality of storage batteries is further provided.
    The command unit calculates the SOC value of each of the plurality of storage batteries based on the output voltage of each of the plurality of storage batteries measured by the voltage measuring unit.
    The offset power command value is determined based on the measurement error of the output power of each of the plurality of storage batteries by the voltage measuring unit.
    The power conditioner according to any one of claims 3 to 5.
  7. 　２つの蓄電池と、
    　直流バスラインと、
    　前記２つの蓄電池それぞれと前記直流バスラインとの間に１つずつ設けられ、前記２つの蓄電池のいずれか１つから出力される直流電力を変換して前記直流バスラインへ出力することにより前記２つの蓄電池からの放電を実行する放電モードまたは前記直流バスラインから供給される直流電力を変換して前記２つの蓄電池のうちのいずれか１つへ出力することにより前記２つの蓄電池のうちのいずれか１つを充電する充電モードで動作する２つの双方向ＤＣ－ＤＣコンバータと、
    　前記２つの双方向ＤＣ－ＤＣコンバータそれぞれについて、前記放電モードで動作させる場合の放電電力指令値または前記充電モードで動作させる場合の充電電力指令値を算出し、算出した前記放電電力指令値または前記充電電力指令値を示す指令値情報を出力する指令部と、
    　前記指令部から出力される前記指令値情報に基づいて、前記２つの双方向ＤＣ－ＤＣコンバータを各別に制御するＤＣ－ＤＣコンバータ制御部と、を備え、
    　前記指令部は、
    　前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように前記放電電力指令値を算出し、
    　前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように前記充電電力指令値を算出する、
    　パワーコンディショナ。     Two storage batteries and
    DC bus line and
    One is provided between each of the two storage batteries and the DC bus line, and the DC power output from any one of the two storage batteries is converted and output to the DC bus line. One of the two storage batteries by performing a discharge mode for executing discharge from the two storage batteries or by converting the DC power supplied from the DC bus line and outputting it to any one of the two storage batteries. Two bidirectional DC-DC converters that operate in charge mode to charge one,
    For each of the two bidirectional DC-DC converters, the discharge power command value when operating in the discharge mode or the charging power command value when operating in the charging mode is calculated, and the calculated discharge power command value or the said A command unit that outputs command value information indicating the charging power command value, and
    A DC-DC converter control unit that separately controls the two bidirectional DC-DC converters based on the command value information output from the command unit is provided.
    The command unit
    When the two bidirectional DC-DC converters are operated in the discharge mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery The discharge power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is larger than the gradient of the SOC value fluctuation with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery. And
    When the two bidirectional DC-DC converters are operated in the charging mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery The charging power command value is calculated so that the gradient of the SOC value fluctuation with respect to time is smaller than the gradient of the SOC value fluctuation with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery. To do,
    Power conditioner.
  8. 　前記指令部は、
    　前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きがゼロとなるように前記放電電力指令値を算出し、
    　前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる場合、前記２つの蓄電池それぞれのＳＯＣ値のいずれか一方が他方よりも大きいとき、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きがゼロとなるように前記充電電力指令値を算出する、
    　請求項７に記載のパワーコンディショナ。     The command unit
    When the two bidirectional DC-DC converters are operated in the discharge mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the other storage battery The discharge power command value is calculated so that the gradient of the fluctuation of the SOC value with respect to time becomes zero.
    When the two bidirectional DC-DC converters are operated in the charging mode, when one of the SOC values of the two storage batteries is larger than the other, the bidirectional DC-DC converter corresponding to the one storage battery The charging power command value is calculated so that the gradient of the fluctuation of the SOC value with respect to time becomes zero.
    The power conditioner according to claim 7.
  9. 　２つの蓄電池と、
    　直流バスラインと、
    　前記２つの蓄電池それぞれと前記直流バスラインとの間に１つずつ設けられ、前記２つの蓄電池のいずれか１つから出力される直流電力を変換して前記直流バスラインへ出力することにより前記２つの蓄電池からの放電を実行する放電モードまたは前記直流バスラインから供給される直流電力を変換して前記２つの蓄電池のうちのいずれか１つへ出力することにより前記２つの蓄電池のうちのいずれか１つを充電する充電モードで動作する２つの双方向ＤＣ－ＤＣコンバータと、
    　前記２つの双方向ＤＣ－ＤＣコンバータを制御するＤＣ－ＤＣコンバータ制御部と、を備え、
    　前記制御部は、
    　前記２つの蓄電池のうちの一方の蓄電池のＳＯＣ値が他方のＳＯＣ値を超えるまでの間、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる第１制御と、前記他方の蓄電池のＳＯＣ値が前記一方のＳＯＣ値を超えるまでの間、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも大きい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる第２制御と、前記一方の蓄電池のＳＯＣ値が前記他方のＳＯＣ値を超えるまでの間、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる第３制御と、前記他方の蓄電池のＳＯＣ値が前記一方のＳＯＣ値を超えるまでの間、前記一方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きを、前記他方の蓄電池に対応する双方向ＤＣ－ＤＣコンバータについての時間に対するＳＯＣ値の変動の傾きよりも小さい値となるように、前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる第４制御と、のうちのいずれ１つを選択して、前記２つの双方向ＤＣ－ＤＣコンバータを制御することが可能であり、前記２つの双方向ＤＣ－ＤＣコンバータを前記放電モードで動作させる場合、前記第１制御と前記第２制御とを交互に実行し、前記２つの双方向ＤＣ－ＤＣコンバータを前記充電モードで動作させる場合、前記第３制御と前記第４制御とを交互に実行する、
    　パワーコンディショナ。     Two storage batteries and
    DC bus line and
    One is provided between each of the two storage batteries and the DC bus line, and the DC power output from any one of the two storage batteries is converted and output to the DC bus line. One of the two storage batteries by performing a discharge mode for executing discharge from the two storage batteries or by converting the DC power supplied from the DC bus line and outputting it to any one of the two storage batteries. Two bidirectional DC-DC converters that operate in charge mode to charge one,
    A DC-DC converter control unit that controls the two bidirectional DC-DC converters is provided.
    The control unit
    Until the SOC value of one of the two storage batteries exceeds the SOC value of the other, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the one storage battery is determined. The first control for operating the two bidirectional DC-DC converters in the discharge mode so that the value is larger than the gradient of the fluctuation of the SOC value with respect to time for the bidirectional DC-DC converter corresponding to the other storage battery. And, until the SOC value of the other storage battery exceeds the SOC value of the one, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the other storage battery is determined by the one storage battery. The second control for operating the two bidirectional DC-DC converters in the discharge mode so that the value becomes larger than the gradient of the fluctuation of the SOC value with respect to time for the bidirectional DC-DC converter corresponding to the above. Until the SOC value of one storage battery exceeds the SOC value of the other storage battery, the gradient of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the other storage battery corresponds to the one storage battery. A third control for operating the two bidirectional DC-DC converters in the charging mode and the other storage battery so that the value becomes smaller than the gradient of the fluctuation of the SOC value with respect to time for the bidirectional DC-DC converter. The slope of the fluctuation of the SOC value with respect to the time for the bidirectional DC-DC converter corresponding to the one storage battery until the SOC value of the above exceeds the SOC value of the other storage battery, and the bidirectional DC corresponding to the other storage battery. Any one of the fourth control for operating the two bidirectional DC-DC converters in the charging mode so that the value is smaller than the gradient of the fluctuation of the SOC value with respect to the time for the -DC converter. When the two bidirectional DC-DC converters can be selectively controlled and the two bidirectional DC-DC converters are operated in the discharge mode, the first control and the second control When the two bidirectional DC-DC converters are operated in the charging mode, the third control and the fourth control are alternately executed.
    Power conditioner.
PCT/JP2020/020332 2019-06-21 2020-05-22 Power conditioner WO2020255624A1 (en)

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