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WO2017038363A1 - Energy management system - Google Patents

Energy management system Download PDF

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Publication number
WO2017038363A1
WO2017038363A1 PCT/JP2016/072888 JP2016072888W WO2017038363A1 WO 2017038363 A1 WO2017038363 A1 WO 2017038363A1 JP 2016072888 W JP2016072888 W JP 2016072888W WO 2017038363 A1 WO2017038363 A1 WO 2017038363A1
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WO
WIPO (PCT)
Prior art keywords
converter
voltage
chopper
bidirectional
llc resonant
Prior art date
Application number
PCT/JP2016/072888
Other languages
French (fr)
Japanese (ja)
Inventor
石倉祐樹
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.)
Filing date
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 JP2017537683A priority Critical patent/JP6327403B2/en
Publication of WO2017038363A1 publication Critical patent/WO2017038363A1/en

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/34—Parallel operation in networks using both storage and other DC sources, e.g. providing buffering
    • H02J7/35—Parallel operation in networks using both storage and other DC sources, e.g. providing buffering with light sensitive cells
    • 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
    • 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
    • H02M3/22—Conversion of DC power input into DC power output with intermediate conversion into AC
    • H02M3/24—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters
    • H02M3/28—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/42—Conversion of DC power input into AC power output without possibility of reversal
    • H02M7/44—Conversion of DC power input into AC power output without possibility of reversal by static converters
    • H02M7/48—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to an energy management system that uses electric power generated in a house or a factory.
  • An energy management system for example, a photovoltaic power generation system, charges a secondary battery with generated power from a power generation device or power from a power system (commercial power supply), and generates generated power or secondary battery discharge power in a house.
  • a bidirectional DC-DC converter is generally used to convert a DC voltage charged or discharged from the secondary battery into a predetermined constant voltage.
  • Patent Document 1 discloses a DC-DC converter that converts voltage with high efficiency at a predetermined ratio while insulating.
  • the DC-DC converter described in Patent Document 1 has a configuration in which a first converter of a bidirectional chopper and a second converter of an insulated bidirectional DC-DC converter are connected. And when charging a secondary battery, a DC voltage is insulated with a 2nd converter, a voltage is adjusted with a 1st converter, and a secondary battery is charged. When discharging the secondary battery, the voltage is converted into a predetermined voltage by the first converter and insulated by the second converter.
  • a bidirectional DC-DC converter in an energy management system is connected to a DC voltage bus (HVDC bus).
  • a power generation device, an inverter, and the like are connected to the HVDC bus.
  • the bi-directional DC-DC converter in order to stabilize the output from the inverter, the bi-directional DC-DC converter is controlled to charge and discharge the secondary battery, so that the voltage of the HVDC bus always maintains a predetermined voltage value. You are in control.
  • the second converter (on the side opposite to the connection with the first converter) is connected to the HVDC bus. For this reason, when the voltage of the HVDC bus decreases and the secondary battery is discharged and applied to the HVDC bus, the second converter needs to be driven so that the output voltage approaches the voltage of the HVDC bus. Since the second converter is a current resonance type converter, the voltage conversion ratio is determined by the turns ratio of the transformer under the resonance condition. Therefore, when adjusting the output voltage, the second converter needs to perform PFM control. In this case, the second converter is driven out of the resonance condition, and high-efficiency voltage conversion obtained by driving at the optimum driving frequency cannot always be realized.
  • an object of the present invention is to provide an energy management system capable of simultaneously realizing highly efficient voltage conversion and insulation.
  • the energy management system includes a DC voltage bus, a power generator connected to the DC voltage bus and outputting generated power to the DC voltage bus, and a bidirectional DC- connected to the DC voltage bus.
  • DC converter unit and bi-directional DC-DC converter unit connected to convert input AC voltage into DC voltage, output to DC-DC converter unit, and bi-directional DC-DC converter
  • An inverter that converts a DC voltage input from the unit into an AC voltage, and the bidirectional DC-DC converter unit includes a non-insulated chopper converter having a secondary battery connection unit, the chopper converter, and the inverter.
  • a connection point between the chopper converter and the resonant converter is a front end.
  • the chopper converter transforms a DC voltage input from the connection point and outputs it to the secondary battery connection unit, and also outputs a DC voltage input from the secondary battery connection unit.
  • the resonant converter transforms the DC voltage input from the connection point and outputs to the inverter, and transforms the DC voltage input from the inverter to the connection It outputs to the point.
  • the voltage can be transformed to a predetermined value by the chopper converter, and the inverter side and the DC voltage bus side can be insulated by the resonance converter.
  • the input voltage to the resonant converter can be kept constant even if the power output from the power generator varies. It can be driven with high efficiency. As a result, the energy management system can realize high-efficiency voltage conversion and insulation at the same time.
  • Each of the chopper converter and the resonant converter includes a switching element
  • the energy management system further includes a control unit that performs switching control of the chopper converter and the resonant converter, and the control unit includes both
  • a configuration may be employed in which the chopper converter is soft-started when starting the DC-DC converter unit.
  • the input voltage to the resonant converter (the output voltage of the chopper converter) is lower than the steady state when starting the resonant converter. Can be suppressed. For this reason, it is not necessary to configure a resonant converter with an element having a high breakdown voltage. In addition, the resonant converter does not need to be driven in a region where the drive frequency is greatly deviated from the resonance frequency for the purpose of reducing the voltage conversion ratio in order to suppress the inrush current. High-efficiency driving is possible immediately after startup.
  • the control unit may perform switching control of the resonant converter at a fixed frequency after the bidirectional DC-DC converter unit is activated.
  • This configuration eliminates the need for PFM control of the resonant converter and allows constant control at a highly efficient frequency.
  • the control unit may activate the chopper converter and the resonant converter at the same time.
  • FIG. 1 is a diagram illustrating a configuration of an energy management system according to an embodiment.
  • FIG. 2 is a circuit diagram of the power generator and the bidirectional DC-DC converter.
  • FIG. 3 is a circuit diagram of the inverter.
  • FIG. 4 is a diagram illustrating a time chart of gate signals applied to the chopper converter and the LLC resonant converter.
  • FIG. 5 shows the frequency characteristics of the LLC resonant converter.
  • FIG. 1 is a diagram showing a configuration of an energy management system 1 according to the present embodiment.
  • the energy management system 1 includes an HVDC bus 10, a power generator 20, a bidirectional DC-DC converter 30, and an inverter 40.
  • a power generator 20 and a bidirectional DC-DC converter 30 are connected to the HVDC bus 10.
  • the HVDC bus 10 corresponds to a “DC voltage bus” according to the present invention.
  • the bidirectional DC-DC converter 30 corresponds to a “bidirectional DC-DC converter unit” according to the present invention.
  • the power generation device 20 includes a photovoltaic panel 21 and a PV converter 22.
  • the PV converter 22 outputs the electric power generated by the photovoltaic panel 21 to the HVDC bus 10.
  • the power generation device 20 may be a wind power generation device or a gas power generation device.
  • the bidirectional DC-DC converter 30 includes a chopper converter 31, an LLC resonance converter 32, and a control unit 33. As will be described in detail later, the chopper converter 31 and the LLC resonant converter 32 each have switching elements, and the control unit 33 performs switching control of these switching elements.
  • the chopper converter 31 and the LLC resonant converter 32 are connected in series.
  • the HVDC bus 10 is connected to a connection point between the chopper converter 31 and the LLC resonant converter 32. That is, the chopper converter 31 and the LLC resonant converter 32 are each connected to the HVDC bus 10. Further, the secondary battery B ⁇ b> 1 is connected to the chopper converter 31.
  • An inverter 40 is connected to the LLC resonant converter 32.
  • the chopper converter 31 is a non-insulated bidirectional chopper circuit.
  • the chopper converter 31 transforms (steps up or steps down) the DC voltage input from one side and outputs it from the other side. That is, the chopper converter 31 transforms the voltage input from the secondary battery B ⁇ b> 1 and outputs it to the HVDC bus 10. Thereby, the secondary battery B1 is discharged. Further, the chopper converter 31 transforms the voltage input from the HVDC bus 10 and outputs it to the secondary battery B1. Thereby, the secondary battery B1 is charged.
  • the LLC resonant converter 32 is an insulating bidirectional DC-DC converter.
  • the LLC resonant converter 32 insulates and transforms the DC voltage input from the HVDC bus 10 at a predetermined ratio, and outputs it to the inverter 40.
  • the inverter 40 converts the alternating voltage input from the electric power grid
  • the direct current voltage converted by the inverter 40 is input to the LLC resonant converter 32.
  • the LLC resonant converter 32 insulates and transforms the input DC voltage at a predetermined ratio and outputs it to the HVDC bus 10.
  • the inverter 40 is connected to the power system 101 and the distribution board 102 through the switches S1 and S2.
  • An AC output terminal (AC outlet or the like) (not shown) is connected to the distribution board 102.
  • a load such as a microwave oven, a washing machine, and an air conditioner is connected to the AC output terminal.
  • the inverter 40 converts the DC voltage input from the bidirectional DC-DC converter 30 into an AC voltage and outputs the AC voltage to the power system 101 side. Further, the inverter 40 converts an AC voltage input from the power system 101 side into a DC voltage and outputs the DC voltage to the bidirectional DC-DC converter 30.
  • the energy management system 1 controls the power generator 20 and the bidirectional DC-DC converter 30 so that the voltage of the HVDC bus 10 maintains a predetermined value (for example, 380 V). By stabilizing the voltage of the HVDC bus 10, constant power can be stably output from the inverter 40 to the power system 101 or the distribution board 102 side.
  • a predetermined value for example, 380 V.
  • FIG. 2 is a circuit diagram of the power generator 20 and the bidirectional DC-DC converter 30.
  • FIG. 3 is a circuit diagram of the inverter 40.
  • PV converter 22 as shown in FIG. 2, includes an input terminal 22I 1, 22I 2, and an output terminal 22O 1, 22O 2.
  • the input terminals 22I 1 and 22I 2 are connected to the photovoltaic panel 21.
  • Output 22O 1, 22O 2 is connected to the HVDC bus 10.
  • An input terminal 22I 1, 22I 2, between the output terminal 22O 1, 22O 2, inductor 22L, a diode 22D, a chopper circuit comprising a switching element 22S and the capacitor 22C is connected.
  • the PV converter 22 performs switching control of the switching element 22S so that the output voltages from the output terminals 22O 1 and 22O 2 approach the target value.
  • the output voltage from the output terminals 22O 1 and 22O 2 is also the voltage of the HVDC bus 10. Therefore, this control maintains the voltage of the HVDC bus 10 at a predetermined value.
  • the inverter 40 includes input / output terminals 40IO 1 and 40IO 2 and AC connection terminals U, V, and W.
  • the input / output terminals 40IO 1 and 40IO 2 are connected to the LLC resonant converter 32.
  • the AC connection ends U, V, and W are connected to the power system 101 and the distribution board 102 via the switches S1 and S2.
  • Switch circuits by switching elements 40S 1 , 40S 2 , 40S 3 , 40S 4 , 40S 5 , 40S 6 are connected to the input / output terminals 40IO 1 , 40IO 2 .
  • the connection point of the switching elements 40S 1 and 40S 2 is connected to the AC connection end U via the inductor Lu.
  • the connection point of the switching elements 40S 3 and 40S 4 is connected to the AC connection terminal V via the inductor Lv.
  • the connection point of the switching elements 40S 5 and 40S 6 is connected to the AC connection end W via the inductor Lw.
  • Capacitors Cu, Cv, and Cw are connected between the AC connection terminals U, V, and W and the neutral point, respectively.
  • the chopper converter 31 of the bidirectional DC-DC converter 30 includes input / output terminals 31IO 1 , 31IO 2 , 31IO 3 and 31IO 4 .
  • a secondary battery B1 is connected to the input / output terminals 31IO 1 and 31IO 2 .
  • the input / output terminals 31IO 1 and 31IO 2 correspond to the “secondary battery connection unit” according to the present invention.
  • the input / output terminals 31IO 3 and 31IO 4 are connected to the LLC resonant converter 32 and the HVDC bus 10.
  • a non-insulated bidirectional chopper circuit is connected between the input / output terminals 31IO 1 and 31IO 2 and the input / output terminals 31IO 3 and 31IO 4 .
  • This bidirectional chopper circuit includes an inductor 31L, switching elements 31S 1 and 31S 2 and a capacitor 31C.
  • the switching elements 31S 1 and 31S 2 are, for example, n-type MOS-FETs, and their gates are connected to the control unit 33. And a gate signal is applied by the control part 33, and it turns on and off.
  • the LLC resonant converter 32 of the bidirectional DC-DC converter 30 includes input / output terminals 32IO 1 , 32IO 2 , 32IO 3 , 32IO 4 .
  • the input / output terminals 32IO 1 and 32IO 2 are connected to the input / output terminals 31IO 3 and 31IO 4 of the chopper converter 31 and the HVDC bus 10.
  • the input / output terminals 32IO 3 and 32IO 4 are connected to the input / output terminals 40IO 1 and 40IO 2 of the inverter 40.
  • a first switch circuit is connected to the input / output terminals 32IO 1 and 32IO 2 .
  • the first switch circuit includes switching elements 32S 1 , 32S 2 , 32S 3 , 32S 4 .
  • the input and output ends 32IO 3, 32IO 4 is a smoothing capacitor 32C 2 and the second switch circuit is connected.
  • the second switch circuit includes switching elements 32S 5 , 32S 6 , 32S 7 , 32S 8 .
  • the switching elements 32S 1 to 32S 8 are, for example, n-type MOS-FETs, and their gates are connected to the control unit 33. And a gate signal is applied by the control part 33, and it turns on and off.
  • the resonance inductor 32L, a resonance capacitor 32C 1 and the transformer T1 is connected.
  • the transformer T1 is shown as an ideal transformer.
  • Resonant inductor 32L and a resonance capacitor 32C 1 constitute the exciting inductance Lm and LLC resonant circuit of the transformer T1.
  • high voltage conversion efficiency can be obtained by bringing the switching frequency of the first switch circuit or the second switch circuit close to the resonance frequency of the LLC resonant circuit. For example, when a DC voltage input from the input / output terminals 32IO 1 and 32IO 2 is output from the input / output terminals 32IO 3 and 32IO 4 , the switching elements 32S 1 and 32S 4 and the switching elements 32S 2 and 32S 3 are set to 50%. High voltage conversion efficiency can be obtained by turning on and off with a duty and setting the switching frequency to the resonance frequency. The conversion ratio at the time of voltage conversion is determined by the turn ratio between the primary winding and the secondary winding of the transformer T1.
  • the energy management system 1 has a configuration in which the HVDC bus 10 is connected to a connection point between the chopper converter 31 and the LLC resonant converter 32 included in the bidirectional DC-DC converter 30. With this configuration, when the charging voltage of the secondary battery B1 is output from the inverter 40, the energy management system 1 can perform voltage conversion with high efficiency while ensuring insulation between the secondary battery B1 and the inverter 40. This will be specifically described below.
  • the chopper converter 31 transforms the charging voltage of the secondary battery B1 to a predetermined voltage. As described above, the chopper converter 31 is connected to the HVDC bus 10. The voltage of the HVDC bus 10 needs to be maintained at a predetermined value. Therefore, the chopper converter 31 performs switching control of the switching elements 31S 1 and 31S 2 so that the output voltage approaches the target value.
  • the LLC resonant converter 32 transforms the voltage transformed by the chopper converter 31 at a predetermined ratio while ensuring insulation. At this time, the LLC resonant converter 32 performs switching control of the switching elements 32S 1 to 32S 4 at the most efficient switching frequency, that is, the resonant frequency of the LLC resonant circuit.
  • the LLC resonant converter 32 is connected to the HVDC bus 10. In this case, it is necessary to bring the output voltage of the LLC resonant converter 32 close to the target value.
  • the transformation ratio in the LLC resonant converter 32 is determined by the turn ratio of the transformer T1. For this reason, when the output voltage of the LLC resonant converter 32 is brought close to the target value, the LLC resonant converter 32 needs to adjust the output voltage by PFM control. In this case, the LLC resonant converter 32 cannot always be driven with high efficiency.
  • the HVDC bus 10 is configured to be connected to a connection point between the chopper converter 31 and the LLC resonant converter 32.
  • the chopper converter 31 only has to adjust the output voltage, and the LLC resonant converter 32 does not need to adjust the output voltage.
  • the LLC resonant converter 32 can be driven with high efficiency by performing switching control of the switching elements 32S 1 to 32S 4 using the resonant frequency as a switching frequency.
  • the LLC resonant converter 32 can be driven with high efficiency even when the energy management system 1 is activated.
  • FIG. 4 is a diagram showing a time chart of the gate signal applied to the chopper converter 31 and the LLC resonant converter 32.
  • (1) in FIG. 4 is a time chart of the gate signal applied to the switching element 31S 1 of the chopper converter 31.
  • (2) of FIG. 4 is a time chart of the gate signal applied to the switching elements 32S 1 and 32S 4 (or 32S 2 and 32S 3 ) of the LLC resonant converter 32.
  • 4 is a voltage V1 of the HVDC bus 10
  • (4) is an output voltage V2 applied to the inverter 40 from the bidirectional DC-DC converter 30 (output voltages of the input / output terminals 32IO 3 and 32IO 4 ). .
  • the control unit 33 activates the chopper converter 31 and the LLC resonant converter 32 simultaneously. Immediately after startup, the control unit 33 soft-starts the chopper converter 31. As a result, as shown in FIG. 4 (3), the output voltage from the chopper converter 31, that is, the voltage V1 of the HVDC bus 10 rises gently. As a result, the inrush current can be prevented from flowing into the LLC resonant converter 32.
  • the control unit 33 can drive the LLC resonant converter 32 with high efficiency immediately after startup. That is, the control unit 33 sets the resonance frequency to the switching frequency, except for the minimum dead time for preventing the through current from flowing through the switching elements 32S 1 and 32S 4 and the switching elements 32S 2 and 32S 3. ON / OFF at about 50% duty.
  • the control unit 33 soft-starts the chopper converter 31, and when the output voltage of the chopper converter 31 reaches the target value, the control unit 33 ends the soft start and performs PWM control so that the output voltage maintains the target value. Further, the controller 33 continues to drive the LLC resonant converter 32 at the same frequency even after the soft start of the chopper converter 31 is completed.
  • the LLC resonant converter 32 can always be driven with high efficiency immediately after startup. Further, by suppressing the inrush current to the LLC resonance converter 32, each element of the LLC resonance converter 32 does not need to be an element having a high withstand voltage.
  • the rush current to the LLC resonant converter 32 is suppressed by soft-starting the chopper converter 31, but the rush current to the LLC resonant converter 32 by simultaneously starting the chopper converter 31 and the LLC resonant converter 32. Can be further suppressed.
  • the chopper converter 31 is driven first, the LLC resonant converter 32 is driven while the capacitor 31C of the chopper converter 31 is charged. In this case, an inrush current may flow into the LLC resonant converter 32 due to the charging voltage of the capacitor 31C. For this reason, the inrush current can be suppressed by simultaneously starting the chopper converter 31 and the LLC resonant converter 32.
  • the chopper converter 31 and the LLC resonant converter 32 are activated simultaneously. However, after the chopper converter 31 is activated first, the LLC resonant converter 32 is activated during the soft start period of the chopper converter 31. You may do it. Even in this case, since the capacitor 31C is not fully charged, the inrush current can be suppressed.
  • control unit 33 continues to drive the LLC resonant converter 32 at the same frequency both at the start and after the soft start of the chopper converter 31.
  • the LLC resonant converter 32 does not necessarily have to be continuously driven at a fixed frequency.
  • FIG. 5 shows the frequency characteristics of the LLC resonant converter.
  • the horizontal axis is “drive frequency / resonance frequency”, and the vertical axis is “voltage gain (voltage gain)”. Further, in FIG. 5, four types of loads from light loads to heavy loads are graphed as separate curves.
  • Voltage gain means the ratio of the input voltage to the output voltage (output voltage / input voltage).
  • K in FIG. 5 means the minimum value of “voltage gain” at the time of steady operation of the LLC resonant converter (during normal operation after the end of soft start). That is, in this modification, the LLC resonant converter is driven in a predetermined frequency range including the frequency with the highest efficiency during normal operation, and “K” is “voltage gain” in the predetermined frequency range. "Means the minimum value.
  • the LLC resonant converter in order to further suppress the inrush current in the LLC resonant converter, the LLC resonant converter is started to be driven from a frequency at which the voltage gain K is reached during the soft start period of the chopper converter.
  • the drive since the drive is started from the frequency at which the voltage gain K is obtained instead of the frequency at which the efficiency is highest, the inrush current is suppressed while the LLC resonant converter is started to be driven at a relatively high efficiency frequency. can do.
  • the control unit may perform switching control of the LLC resonant converter at a frequency (in the vicinity of the resonant frequency) with higher efficiency.
  • the LLC resonant converter according to the present modification is driven at a frequency that provides a voltage gain of “K” or more at both the soft start period and the normal operation, so that a relatively high-efficiency frequency is achieved.
  • the inrush current is also suppressed while maintaining the drive.
  • B1 Secondary batteries Cu, Cv, Cw ... Capacitor Lm ... Excitation inductances Lu, Lv, Lw ... Inductors S1, S2 ... Switch T1 ... Transformer U, V, W ... AC connection end 1 ... Energy management system 10 ... HVDC bus 20 ... power generator 21 ... photovoltaic panels 22 ... PV converter 22C ... capacitor 22D ... diodes 22I 1, 22I 2 ... inputs 22L ... inductor 22O 1, 22O 2 ... output terminal 22S ... switching device 30 ... DC-DC converter 31 ... chopper converter 31C ... capacitor 31IO 1, 31IO 2, 31IO 3 , 31IO 4 ... output terminal 31L ... inductor 31S 1, 31S 2 ...

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)
  • Inverter Devices (AREA)

Abstract

An energy management system (1) is provided with: a power generation device (20) connected to a HVDC bus (10); a bidirectional DC-DC converter (30) connected to the HVDC bus (10); and an inverter (40) connected to the bidirectional DC-DC converter (30). The bidirectional DC-DC converter (30) is configured by connecting in series a non-insulating chopper converter (31), and an insulating LLC resonant converter (32), and the HVDC bus (10) is connected to a connection point between the non-insulating chopper converter and the insulating LLC resonant converter. The chopper converter (31) transforms a charge voltage of a secondary battery (B1) to a predetermined value, and outputs the voltage to the HVDC bus (10). The LLC resonant converter (32) transforms a direct current voltage inputted from the HVDC bus (10), and outputs the voltage to an inverter (40). Consequently, the energy management system, which is capable of achieving highly efficient voltage conversion and insulation at one time, is provided.

Description

エネルギーマネジメントシステムEnergy management system
　本発明は、住宅又は工場等において発電された電力を使用するエネルギーマネジメントシステムに関する。 The present invention relates to an energy management system that uses electric power generated in a house or a factory.
　エネルギーマネジメントシステム、例えば太陽光発電システムは、発電装置からの発電電力、又は電力系統（商用電源）からの電力で二次電池を充電し、また、発電電力又は二次電池の放電電力を住宅内の分電盤へ供給する。この太陽光発電システムでは、二次電池に対して充電又は二次電池から放電される直流電圧を所定の定電圧に変換するために、双方向ＤＣ－ＤＣコンバータが一般的に用いられる。 An energy management system, for example, a photovoltaic power generation system, charges a secondary battery with generated power from a power generation device or power from a power system (commercial power supply), and generates generated power or secondary battery discharge power in a house. To the distribution board. In this solar power generation system, a bidirectional DC-DC converter is generally used to convert a DC voltage charged or discharged from the secondary battery into a predetermined constant voltage.
　特許文献１には、絶縁しつつ、所定の比率で電圧を高効率に変換するＤＣ－ＤＣコンバータが開示されている。特許文献１に記載のＤＣ－ＤＣコンバータは、双方向チョッパの第１コンバータと、絶縁型双方向ＤＣ－ＤＣコンバータの第２コンバータとが接続された構成である。そして、二次電池を充電する場合は、直流電圧を第２コンバータで絶縁し、第１コンバータで電圧を調整して二次電池を充電する。二次電池を放電する場合は、第１コンバータで電圧を所定の電圧に変換し、第２コンバータで絶縁する。 Patent Document 1 discloses a DC-DC converter that converts voltage with high efficiency at a predetermined ratio while insulating. The DC-DC converter described in Patent Document 1 has a configuration in which a first converter of a bidirectional chopper and a second converter of an insulated bidirectional DC-DC converter are connected. And when charging a secondary battery, a DC voltage is insulated with a 2nd converter, a voltage is adjusted with a 1st converter, and a secondary battery is charged. When discharging the secondary battery, the voltage is converted into a predetermined voltage by the first converter and insulated by the second converter.
特開２０１５－１２６４５号公報JP2015-12645A
　一般的に、エネルギーマネジメントシステムにおける双方向ＤＣ－ＤＣコンバータは、直流電圧バス（ＨＶＤＣバス）に接続されている。このＨＶＤＣバスには、発電装置及びインバータ等が接続されている。そして、エネルギーマネジメントシステムでは、インバータからの出力を安定させるために、双方向ＤＣ－ＤＣコンバータを制御して二次電池を充放電させるなどして、ＨＶＤＣバスの電圧が常に所定の電圧値を維持するように制御している。 Generally, a bidirectional DC-DC converter in an energy management system is connected to a DC voltage bus (HVDC bus). A power generation device, an inverter, and the like are connected to the HVDC bus. In the energy management system, in order to stabilize the output from the inverter, the bi-directional DC-DC converter is controlled to charge and discharge the secondary battery, so that the voltage of the HVDC bus always maintains a predetermined voltage value. You are in control.
　特許文献１に記載のＤＣ－ＤＣコンバータを用いた場合、第２コンバータ（第１のコンバータとの接続部との反対側）がＨＶＤＣバスに接続される構成となる。このため、ＨＶＤＣバスの電圧が低下し、二次電池を放電してＨＶＤＣバスへ電圧を印加する場合、第２コンバータは、出力電圧がＨＶＤＣバスの電圧に近づくよう駆動する必要がある。第２コンバータは、電流共振型コンバータであるため、共振条件下においてはトランスの巻数比によって電圧変換比率が決まる。このため、出力電圧を調整する際には、第２コンバータはＰＦＭ制御を行う必要がある。この場合、第２コンバータは、共振条件を外れて駆動することとなり、最適な駆動周波数で駆動することで得られる高効率電圧変換を常時実現できない。 When the DC-DC converter described in Patent Document 1 is used, the second converter (on the side opposite to the connection with the first converter) is connected to the HVDC bus. For this reason, when the voltage of the HVDC bus decreases and the secondary battery is discharged and applied to the HVDC bus, the second converter needs to be driven so that the output voltage approaches the voltage of the HVDC bus. Since the second converter is a current resonance type converter, the voltage conversion ratio is determined by the turns ratio of the transformer under the resonance condition. Therefore, when adjusting the output voltage, the second converter needs to perform PFM control. In this case, the second converter is driven out of the resonance condition, and high-efficiency voltage conversion obtained by driving at the optimum driving frequency cannot always be realized.
　そこで、本発明の目的は、高効率な電圧変換と、絶縁とを同時に実現できるエネルギーマネジメントシステムを提供することにある。 Therefore, an object of the present invention is to provide an energy management system capable of simultaneously realizing highly efficient voltage conversion and insulation.
　本発明に係るエネルギーマネジメントシステムは、直流電圧バスと、前記直流電圧バスに接続され、発電された電力を前記直流電圧バスへ出力する発電装置と、前記直流電圧バスに接続された双方向ＤＣ－ＤＣコンバータ部と、前記双方向ＤＣ－ＤＣコンバータ部に接続され、入力される交流電圧を直流電圧に変換し、前記双方向ＤＣ－ＤＣコンバータ部へ出力し、また、前記双方向ＤＣ－ＤＣコンバータ部から入力される直流電圧を交流電圧に変換するインバータと、を備え、前記双方向ＤＣ－ＤＣコンバータ部は、二次電池接続部を有する非絶縁型のチョッパコンバータと、前記チョッパコンバータと前記インバータとに接続された絶縁型の共振コンバータと、を含み、前記チョッパコンバータと前記共振コンバータとの接続点は、前記直流電圧バスに接続され、前記チョッパコンバータは、前記接続点から入力される直流電圧を変圧して前記二次電池接続部へ出力し、また、前記二次電池接続部から入力される直流電圧を変圧して前記接続点へ出力し、前記共振コンバータは、前記接続点から入力される直流電圧を変圧して前記インバータへ出力し、また、前記インバータから入力される直流電圧を変圧して前記接続点へ出力することを特徴とする。 The energy management system according to the present invention includes a DC voltage bus, a power generator connected to the DC voltage bus and outputting generated power to the DC voltage bus, and a bidirectional DC- connected to the DC voltage bus. DC converter unit and bi-directional DC-DC converter unit connected to convert input AC voltage into DC voltage, output to DC-DC converter unit, and bi-directional DC-DC converter An inverter that converts a DC voltage input from the unit into an AC voltage, and the bidirectional DC-DC converter unit includes a non-insulated chopper converter having a secondary battery connection unit, the chopper converter, and the inverter. A connection point between the chopper converter and the resonant converter is a front end. Connected to a DC voltage bus, the chopper converter transforms a DC voltage input from the connection point and outputs it to the secondary battery connection unit, and also outputs a DC voltage input from the secondary battery connection unit. Transform and output to the connection point, the resonant converter transforms the DC voltage input from the connection point and outputs to the inverter, and transforms the DC voltage input from the inverter to the connection It outputs to the point.
　この構成では、チョッパコンバータで電圧を所定値に変圧でき、共振コンバータでインバータ側と直流電圧バス側とを絶縁できる。また、チョッパコンバータで所定値に変圧することで、発電装置から出力される電力に変動があっても、共振コンバータへの入力電圧を一定にできるため、共振コンバータは、変圧比を考慮することなく高効率に駆動することができる。その結果、エネルギーマネジメントシステムは、高効率な電圧変換と、絶縁とを同時に実現できる。 In this configuration, the voltage can be transformed to a predetermined value by the chopper converter, and the inverter side and the DC voltage bus side can be insulated by the resonance converter. In addition, by transforming to a predetermined value with a chopper converter, the input voltage to the resonant converter can be kept constant even if the power output from the power generator varies. It can be driven with high efficiency. As a result, the energy management system can realize high-efficiency voltage conversion and insulation at the same time.
　前記チョッパコンバータ、及び前記共振コンバータはそれぞれ、スイッチング素子を有し、前記エネルギーマネジメントシステムは、前記チョッパコンバータ、及び前記共振コンバータを、スイッチング制御する制御部、をさらに備え、前記制御部は、前記双方向ＤＣ－ＤＣコンバータ部の起動時に、前記チョッパコンバータをソフトスタート起動させる構成でもよい。 Each of the chopper converter and the resonant converter includes a switching element, and the energy management system further includes a control unit that performs switching control of the chopper converter and the resonant converter, and the control unit includes both A configuration may be employed in which the chopper converter is soft-started when starting the DC-DC converter unit.
　この構成では、チョッパコンバータをソフトスタート起動させることで、共振コンバータの起動時において、共振コンバータへの入力電圧（チョッパコンバータの出力電圧）が定常状態に比べて低いため、共振コンバータへの突入電流を抑制できる。このため、耐圧の高い素子で共振コンバータを構成する必要がない。また、共振コンバータは、突入電流抑制のために電圧変換比を下げる目的で、駆動周波数を共振周波数から大きく外れた領域で駆動する必要がなくなり、共振周波数又は共振周波数に近接した周波数を駆動周波数とする高効率駆動が、起動直後から可能となる。 In this configuration, by soft-starting the chopper converter, the input voltage to the resonant converter (the output voltage of the chopper converter) is lower than the steady state when starting the resonant converter. Can be suppressed. For this reason, it is not necessary to configure a resonant converter with an element having a high breakdown voltage. In addition, the resonant converter does not need to be driven in a region where the drive frequency is greatly deviated from the resonance frequency for the purpose of reducing the voltage conversion ratio in order to suppress the inrush current. High-efficiency driving is possible immediately after startup.
　前記制御部は、前記双方向ＤＣ－ＤＣコンバータ部を起動して以降、固定周波数で前記共振コンバータをスイッチング制御してもよい。 The control unit may perform switching control of the resonant converter at a fixed frequency after the bidirectional DC-DC converter unit is activated.
　この構成では、共振コンバータをＰＦＭ制御する必要がなく、高効率な周波数で常時制御することができる。 This configuration eliminates the need for PFM control of the resonant converter and allows constant control at a highly efficient frequency.
　前記制御部は、前記チョッパコンバータ、及び前記共振コンバータを同時に起動してもよい。 The control unit may activate the chopper converter and the resonant converter at the same time.
　この構成では、チョッパコンバータから共振コンバータへ突入電流が流れ込むおそれを抑制できる。例えば、チョッパコンバータがキャパシタを有し、チョッパコンバータの起動後に共振コンバータを起動させた場合、キャパシタが充電された状態で共振コンバータを駆動することになる。この場合、キャパシタの充電電圧によって、共振コンバータに突入電流が流れ込むおそれがある。これに対し、上記構成では、チョッパコンバータ及び共振コンバータを同時に起動されることで、突入電流の流れ込みを防止できる。 ∙ With this configuration, the risk of inrush current flowing from the chopper converter to the resonant converter can be suppressed. For example, when the chopper converter has a capacitor and the resonance converter is activated after the chopper converter is activated, the resonance converter is driven while the capacitor is charged. In this case, an inrush current may flow into the resonant converter due to the charging voltage of the capacitor. On the other hand, in the above configuration, inrush current can be prevented from flowing by simultaneously starting the chopper converter and the resonant converter.
　本発明によれば、高効率な電圧変換と、絶縁とを同時に実現できるエネルギーマネジメントシステムを提供できる。 According to the present invention, it is possible to provide an energy management system capable of realizing high-efficiency voltage conversion and insulation at the same time.
図１は、実施形態に係るエネルギーマネジメントシステムの構成を示す図である。FIG. 1 is a diagram illustrating a configuration of an energy management system according to an embodiment. 図２は、発電装置及び双方向ＤＣ－ＤＣコンバータの回路図である。FIG. 2 is a circuit diagram of the power generator and the bidirectional DC-DC converter. 図３は、インバータの回路図である。FIG. 3 is a circuit diagram of the inverter. 図４は、チョッパコンバータとＬＬＣ共振コンバータとに印加するゲート信号のタイムチャートを示す図である。FIG. 4 is a diagram illustrating a time chart of gate signals applied to the chopper converter and the LLC resonant converter. 図５は、ＬＬＣ共振コンバータの周波数特性を示す。FIG. 5 shows the frequency characteristics of the LLC resonant converter.
　図１は、本実施形態に係るエネルギーマネジメントシステム１の構成を示す図である。 FIG. 1 is a diagram showing a configuration of an energy management system 1 according to the present embodiment.
　エネルギーマネジメントシステム１は、ＨＶＤＣバス１０、発電装置２０、双方向ＤＣ－ＤＣコンバータ３０及びインバータ４０を備えている。ＨＶＤＣバス１０には、発電装置２０及び双方向ＤＣ－ＤＣコンバータ３０が接続されている。ＨＶＤＣバス１０は、本発明に係る「直流電圧バス」に相当する。また、双方向ＤＣ－ＤＣコンバータ３０は、本発明に係る「双方向ＤＣ－ＤＣコンバータ部」に相当する。 The energy management system 1 includes an HVDC bus 10, a power generator 20, a bidirectional DC-DC converter 30, and an inverter 40. A power generator 20 and a bidirectional DC-DC converter 30 are connected to the HVDC bus 10. The HVDC bus 10 corresponds to a “DC voltage bus” according to the present invention. The bidirectional DC-DC converter 30 corresponds to a “bidirectional DC-DC converter unit” according to the present invention.
　発電装置２０は、光発電パネル２１とＰＶコンバータ２２とを備えている。ＰＶコンバータ２２は、光発電パネル２１で発生した電力をＨＶＤＣバス１０へ出力する。なお、発電装置２０は、風力発電装置又はガス発電装置等であってもよい。 The power generation device 20 includes a photovoltaic panel 21 and a PV converter 22. The PV converter 22 outputs the electric power generated by the photovoltaic panel 21 to the HVDC bus 10. The power generation device 20 may be a wind power generation device or a gas power generation device.
　双方向ＤＣ－ＤＣコンバータ３０は、チョッパコンバータ３１と、ＬＬＣ共振コンバータ３２と、制御部３３とを有している。後に詳述するが、チョッパコンバータ３１及びＬＬＣ共振コンバータ３２はそれぞれスイッチング素子を有し、制御部３３は、それらのスイッチング素子をスイッチング制御する。 The bidirectional DC-DC converter 30 includes a chopper converter 31, an LLC resonance converter 32, and a control unit 33. As will be described in detail later, the chopper converter 31 and the LLC resonant converter 32 each have switching elements, and the control unit 33 performs switching control of these switching elements.
　チョッパコンバータ３１とＬＬＣ共振コンバータ３２とは直列に接続されている。また、チョッパコンバータ３１とＬＬＣ共振コンバータ３２との接続点には、ＨＶＤＣバス１０が接続されている。すなわち、チョッパコンバータ３１及びＬＬＣ共振コンバータ３２はそれぞれ、ＨＶＤＣバス１０に接続されている。また、チョッパコンバータ３１には二次電池Ｂ１が接続されている。ＬＬＣ共振コンバータ３２にはインバータ４０が接続されている。 The chopper converter 31 and the LLC resonant converter 32 are connected in series. The HVDC bus 10 is connected to a connection point between the chopper converter 31 and the LLC resonant converter 32. That is, the chopper converter 31 and the LLC resonant converter 32 are each connected to the HVDC bus 10. Further, the secondary battery B <b> 1 is connected to the chopper converter 31. An inverter 40 is connected to the LLC resonant converter 32.
　チョッパコンバータ３１は、非絶縁型の双方向チョッパ回路である。チョッパコンバータ３１は、一方から入力される直流電圧を変圧（昇圧又は降圧）し、他方から出力する。すなわち、チョッパコンバータ３１は、二次電池Ｂ１から入力される電圧を変圧し、ＨＶＤＣバス１０へ出力する。これにより、二次電池Ｂ１は放電される。また、チョッパコンバータ３１は、ＨＶＤＣバス１０から入力される電圧を変圧し、二次電池Ｂ１へ出力する。これにより、二次電池Ｂ１は充電される。 The chopper converter 31 is a non-insulated bidirectional chopper circuit. The chopper converter 31 transforms (steps up or steps down) the DC voltage input from one side and outputs it from the other side. That is, the chopper converter 31 transforms the voltage input from the secondary battery B <b> 1 and outputs it to the HVDC bus 10. Thereby, the secondary battery B1 is discharged. Further, the chopper converter 31 transforms the voltage input from the HVDC bus 10 and outputs it to the secondary battery B1. Thereby, the secondary battery B1 is charged.
　ＬＬＣ共振コンバータ３２は、絶縁型の双方向ＤＣ－ＤＣコンバータである。ＬＬＣ共振コンバータ３２は、ＨＶＤＣバス１０から入力される直流電圧を絶縁及び所定の比率で変圧し、インバータ４０へ出力する。また、後述するが、インバータ４０は、電力系統１０１側から入力される交流電圧を直流電圧に変換する。ＬＬＣ共振コンバータ３２には、そのインバータ４０で変換された直流電圧が入力される。ＬＬＣ共振コンバータ３２は、入力される直流電圧を絶縁及び所定の比率で変圧し、ＨＶＤＣバス１０へ出力する。 The LLC resonant converter 32 is an insulating bidirectional DC-DC converter. The LLC resonant converter 32 insulates and transforms the DC voltage input from the HVDC bus 10 at a predetermined ratio, and outputs it to the inverter 40. Moreover, although mentioned later, the inverter 40 converts the alternating voltage input from the electric power grid | system 101 side into a direct voltage. The direct current voltage converted by the inverter 40 is input to the LLC resonant converter 32. The LLC resonant converter 32 insulates and transforms the input DC voltage at a predetermined ratio and outputs it to the HVDC bus 10.
　インバータ４０は、開閉器Ｓ１，Ｓ２を介して、電力系統１０１と、分電盤１０２とに接続されている。分電盤１０２には、不図示のＡＣ出力端子（ＡＣコンセント等）が接続されている。そのＡＣ出力端子には、電子レンジ、洗濯機、エアコン等の負荷が接続される。インバータ４０は、双方向ＤＣ－ＤＣコンバータ３０から入力される直流電圧を交流電圧に変換し、電力系統１０１側へ出力する。また、インバータ４０は、電力系統１０１側から入力される交流電圧を直流電圧に変換し、双方向ＤＣ－ＤＣコンバータ３０へ出力する。 The inverter 40 is connected to the power system 101 and the distribution board 102 through the switches S1 and S2. An AC output terminal (AC outlet or the like) (not shown) is connected to the distribution board 102. A load such as a microwave oven, a washing machine, and an air conditioner is connected to the AC output terminal. The inverter 40 converts the DC voltage input from the bidirectional DC-DC converter 30 into an AC voltage and outputs the AC voltage to the power system 101 side. Further, the inverter 40 converts an AC voltage input from the power system 101 side into a DC voltage and outputs the DC voltage to the bidirectional DC-DC converter 30.
　このエネルギーマネジメントシステム１は、ＨＶＤＣバス１０の電圧が所定値（例えば、３８０Ｖ）を維持するよう、発電装置２０及び双方向ＤＣ－ＤＣコンバータ３０を制御する。ＨＶＤＣバス１０の電圧を安定させることで、インバータ４０から電力系統１０１又は分電盤１０２側へ、一定の電力を安定して出力させることができる。 The energy management system 1 controls the power generator 20 and the bidirectional DC-DC converter 30 so that the voltage of the HVDC bus 10 maintains a predetermined value (for example, 380 V). By stabilizing the voltage of the HVDC bus 10, constant power can be stably output from the inverter 40 to the power system 101 or the distribution board 102 side.
　以下、発電装置２０のＰＶコンバータ２２、双方向ＤＣ－ＤＣコンバータ３０及びインバータ４０の回路構成について説明する。 Hereinafter, circuit configurations of the PV converter 22, the bidirectional DC-DC converter 30, and the inverter 40 of the power generation apparatus 20 will be described.
　図２は、発電装置２０及び双方向ＤＣ－ＤＣコンバータ３０の回路図である。図３は、インバータ４０の回路図である。 FIG. 2 is a circuit diagram of the power generator 20 and the bidirectional DC-DC converter 30. FIG. 3 is a circuit diagram of the inverter 40.
　ＰＶコンバータ２２は、図２に示すように、入力端２２Ｉ１，２２Ｉ２と、出力端２２Ｏ１，２２Ｏ２とを備えている。入力端２２Ｉ１，２２Ｉ２は、光発電パネル２１に接続されている。出力端２２Ｏ１，２２Ｏ２は、ＨＶＤＣバス１０に接続されている。入力端２２Ｉ１，２２Ｉ２と、出力端２２Ｏ１，２２Ｏ２との間には、インダクタ２２Ｌ、ダイオード２２Ｄ、スイッチング素子２２Ｓ及びコンデンサ２２Ｃからなるチョッパ回路が接続されている。 PV converter 22, as shown in FIG. 2, includes an input terminal 22I 1, 22I 2, and an output terminal 22O 1, 22O 2. The input terminals 22I 1 and 22I 2 are connected to the photovoltaic panel 21. Output 22O 1, 22O 2 is connected to the HVDC bus 10. An input terminal 22I 1, 22I 2, between the output terminal 22O 1, 22O 2, inductor 22L, a diode 22D, a chopper circuit comprising a switching element 22S and the capacitor 22C is connected.
　ＰＶコンバータ２２は、出力端２２Ｏ１，２２Ｏ２からの出力電圧が目標値に近づくように、スイッチング素子２２Ｓをスイッチング制御する。出力端２２Ｏ１，２２Ｏ２からの出力電圧は、ＨＶＤＣバス１０の電圧でもある。したがって、この制御により、ＨＶＤＣバス１０の電圧を所定値に維持する。 The PV converter 22 performs switching control of the switching element 22S so that the output voltages from the output terminals 22O 1 and 22O 2 approach the target value. The output voltage from the output terminals 22O 1 and 22O 2 is also the voltage of the HVDC bus 10. Therefore, this control maintains the voltage of the HVDC bus 10 at a predetermined value.
　インバータ４０は、図３に示すように、入出力端４０ＩＯ１，４０ＩＯ２と、交流接続端Ｕ，Ｖ，Ｗとを備えている。入出力端４０ＩＯ１，４０ＩＯ２は、ＬＬＣ共振コンバータ３２に接続されている。交流接続端Ｕ，Ｖ，Ｗは、開閉器Ｓ１，Ｓ２を介して、電力系統１０１及び分電盤１０２に接続されている。 As shown in FIG. 3, the inverter 40 includes input / output terminals 40IO 1 and 40IO 2 and AC connection terminals U, V, and W. The input / output terminals 40IO 1 and 40IO 2 are connected to the LLC resonant converter 32. The AC connection ends U, V, and W are connected to the power system 101 and the distribution board 102 via the switches S1 and S2.
　入出力端４０ＩＯ１，４０ＩＯ２には、スイッチング素子４０Ｓ１，４０Ｓ２，４０Ｓ３，４０Ｓ４，４０Ｓ５，４０Ｓ６によるスイッチ回路が接続されている。スイッチング素子４０Ｓ１，４０Ｓ２の接続点は、インダクタＬｕを介して交流接続端Ｕに接続されている。スイッチング素子４０Ｓ３，４０Ｓ４の接続点は、インダクタＬｖを介して交流接続端Ｖに接続されている。スイッチング素子４０Ｓ５，４０Ｓ６の接続点は、インダクタＬｗを介して交流接続端Ｗに接続されている。交流接続端Ｕ，Ｖ，Ｗと中性点との間には、コンデンサＣｕ，Ｃｖ，Ｃｗがそれぞれ接続されている。 Switch circuits by switching elements 40S 1 , 40S 2 , 40S 3 , 40S 4 , 40S 5 , 40S 6 are connected to the input / output terminals 40IO 1 , 40IO 2 . The connection point of the switching elements 40S 1 and 40S 2 is connected to the AC connection end U via the inductor Lu. The connection point of the switching elements 40S 3 and 40S 4 is connected to the AC connection terminal V via the inductor Lv. The connection point of the switching elements 40S 5 and 40S 6 is connected to the AC connection end W via the inductor Lw. Capacitors Cu, Cv, and Cw are connected between the AC connection terminals U, V, and W and the neutral point, respectively.
　図２に示すように、双方向ＤＣ－ＤＣコンバータ３０のチョッパコンバータ３１は、入出力端３１ＩＯ１，３１ＩＯ２，３１ＩＯ３，３１ＩＯ４を備えている。入出力端３１ＩＯ１，３１ＩＯ２には二次電池Ｂ１が接続されている。入出力端３１ＩＯ１，３１ＩＯ２は、本発明に係る「二次電池接続部」に相当する。入出力端３１ＩＯ３，３１ＩＯ４は、ＬＬＣ共振コンバータ３２、及びＨＶＤＣバス１０に接続されている。 As shown in FIG. 2, the chopper converter 31 of the bidirectional DC-DC converter 30 includes input / output terminals 31IO 1 , 31IO 2 , 31IO 3 and 31IO 4 . A secondary battery B1 is connected to the input / output terminals 31IO 1 and 31IO 2 . The input / output terminals 31IO 1 and 31IO 2 correspond to the “secondary battery connection unit” according to the present invention. The input / output terminals 31IO 3 and 31IO 4 are connected to the LLC resonant converter 32 and the HVDC bus 10.
　入出力端３１ＩＯ１，３１ＩＯ２と入出力端３１ＩＯ３，３１ＩＯ４との間には、非絶縁型の双方向チョッパ回路が接続されている。この双方向チョッパ回路は、インダクタ３１Ｌ、スイッチング素子３１Ｓ１，３１Ｓ２及びキャパシタ３１Ｃからなる。スイッチング素子３１Ｓ１，３１Ｓ２は、例えばｎ型ＭＯＳ－ＦＥＴであり、これらのゲートが制御部３３に接続されている。そして、制御部３３によりゲート信号が印加されて、オンオフする。 A non-insulated bidirectional chopper circuit is connected between the input / output terminals 31IO 1 and 31IO 2 and the input / output terminals 31IO 3 and 31IO 4 . This bidirectional chopper circuit includes an inductor 31L, switching elements 31S 1 and 31S 2 and a capacitor 31C. The switching elements 31S 1 and 31S 2 are, for example, n-type MOS-FETs, and their gates are connected to the control unit 33. And a gate signal is applied by the control part 33, and it turns on and off.
　双方向ＤＣ－ＤＣコンバータ３０のＬＬＣ共振コンバータ３２は、入出力端３２ＩＯ１，３２ＩＯ２，３２ＩＯ３，３２ＩＯ４を備えている。入出力端３２ＩＯ１，３２ＩＯ２は、チョッパコンバータ３１の入出力端３１ＩＯ３，３１ＩＯ４、及びＨＶＤＣバス１０に接続されている。入出力端３２ＩＯ３，３２ＩＯ４はインバータ４０の入出力端４０ＩＯ１，４０ＩＯ２に接続されている。 The LLC resonant converter 32 of the bidirectional DC-DC converter 30 includes input / output terminals 32IO 1 , 32IO 2 , 32IO 3 , 32IO 4 . The input / output terminals 32IO 1 and 32IO 2 are connected to the input / output terminals 31IO 3 and 31IO 4 of the chopper converter 31 and the HVDC bus 10. The input / output terminals 32IO 3 and 32IO 4 are connected to the input / output terminals 40IO 1 and 40IO 2 of the inverter 40.
　入出力端３２ＩＯ１，３２ＩＯ２には、第１スイッチ回路が接続されている。第１スイッチ回路は、スイッチング素子３２Ｓ１，３２Ｓ２，３２Ｓ３，３２Ｓ４からなる。入出力端３２ＩＯ３，３２ＩＯ４には、平滑コンデンサ３２Ｃ２及び第２スイッチ回路が接続されている。第２スイッチ回路は、スイッチング素子３２Ｓ５，３２Ｓ６，３２Ｓ７，３２Ｓ８からなる。スイッチング素子３２Ｓ１～３２Ｓ８は、例えばｎ型ＭＯＳ－ＦＥＴであり、これらのゲートが制御部３３に接続されている。そして、制御部３３によりゲート信号が印加されて、オンオフする。 A first switch circuit is connected to the input / output terminals 32IO 1 and 32IO 2 . The first switch circuit includes switching elements 32S 1 , 32S 2 , 32S 3 , 32S 4 . The input and output ends 32IO 3, 32IO 4 is a smoothing capacitor 32C 2 and the second switch circuit is connected. The second switch circuit includes switching elements 32S 5 , 32S 6 , 32S 7 , 32S 8 . The switching elements 32S 1 to 32S 8 are, for example, n-type MOS-FETs, and their gates are connected to the control unit 33. And a gate signal is applied by the control part 33, and it turns on and off.
　第１スイッチ回路と第２スイッチ回路との間には、共振用インダクタ３２Ｌ、共振用コンデンサ３２Ｃ１及びトランスＴ１が接続されている。図２では、トランスＴ１は、理想トランスで示している。共振用インダクタ３２Ｌ及び共振用コンデンサ３２Ｃ１は、トランスＴ１の励磁インダクタンスＬｍとＬＬＣ共振回路を構成している。 Between the first switch circuit and the second switch circuit, the resonance inductor 32L, a resonance capacitor 32C 1 and the transformer T1 is connected. In FIG. 2, the transformer T1 is shown as an ideal transformer. Resonant inductor 32L and a resonance capacitor 32C 1 constitute the exciting inductance Lm and LLC resonant circuit of the transformer T1.
　このＬＬＣ共振コンバータ３２では、第１スイッチ回路又は第２スイッチ回路のスイッチング周波数を、ＬＬＣ共振回路の共振周波数に近づけることで、高い電圧変換効率が得られる。例えば、入出力端３２ＩＯ１，３２ＩＯ２から入力する直流電圧を入出力端３２ＩＯ３，３２ＩＯ４から出力する場合、スイッチング素子３２Ｓ１，３２Ｓ４と、スイッチング素子３２Ｓ２，３２Ｓ３とを、５０％デューティでオンオフし、そのスイッチング周波数を共振周波数とすることで、高い電圧変換効率が得られる。なお、電圧変換時の変換比率は、トランスＴ１の一次巻線と二次巻線との巻数比により定まる。 In the LLC resonant converter 32, high voltage conversion efficiency can be obtained by bringing the switching frequency of the first switch circuit or the second switch circuit close to the resonance frequency of the LLC resonant circuit. For example, when a DC voltage input from the input / output terminals 32IO 1 and 32IO 2 is output from the input / output terminals 32IO 3 and 32IO 4 , the switching elements 32S 1 and 32S 4 and the switching elements 32S 2 and 32S 3 are set to 50%. High voltage conversion efficiency can be obtained by turning on and off with a duty and setting the switching frequency to the resonance frequency. The conversion ratio at the time of voltage conversion is determined by the turn ratio between the primary winding and the secondary winding of the transformer T1.
　前記のように、エネルギーマネジメントシステム１は、双方向ＤＣ－ＤＣコンバータ３０が有するチョッパコンバータ３１とＬＬＣ共振コンバータ３２との接続点に、ＨＶＤＣバス１０が接続されている構成である。この構成により、エネルギーマネジメントシステム１は、二次電池Ｂ１の充電電圧をインバータ４０から出力する場合、二次電池Ｂ１とインバータ４０との絶縁を確保しつつ、高効率に電圧変換できる。以下、具体的に説明する。 As described above, the energy management system 1 has a configuration in which the HVDC bus 10 is connected to a connection point between the chopper converter 31 and the LLC resonant converter 32 included in the bidirectional DC-DC converter 30. With this configuration, when the charging voltage of the secondary battery B1 is output from the inverter 40, the energy management system 1 can perform voltage conversion with high efficiency while ensuring insulation between the secondary battery B1 and the inverter 40. This will be specifically described below.
　チョッパコンバータ３１は、二次電池Ｂ１の充電電圧を所定の電圧に変圧する。前記のように、チョッパコンバータ３１はＨＶＤＣバス１０に接続されている。そして、ＨＶＤＣバス１０の電圧は所定値に維持する必要がある。したがって、チョッパコンバータ３１は、出力電圧が目標値に近づくように、スイッチング素子３１Ｓ１，３１Ｓ２をスイッチング制御する。 The chopper converter 31 transforms the charging voltage of the secondary battery B1 to a predetermined voltage. As described above, the chopper converter 31 is connected to the HVDC bus 10. The voltage of the HVDC bus 10 needs to be maintained at a predetermined value. Therefore, the chopper converter 31 performs switching control of the switching elements 31S 1 and 31S 2 so that the output voltage approaches the target value.
　ＬＬＣ共振コンバータ３２は、絶縁を確保しつつ、チョッパコンバータ３１により変圧された電圧を、所定の比率で変圧する。このとき、ＬＬＣ共振コンバータ３２は、最も効率の良いスイッチング周波数、すなわち、ＬＬＣ共振回路の共振周波数で、スイッチング素子３２Ｓ１～３２Ｓ４をスイッチング制御する。 The LLC resonant converter 32 transforms the voltage transformed by the chopper converter 31 at a predetermined ratio while ensuring insulation. At this time, the LLC resonant converter 32 performs switching control of the switching elements 32S 1 to 32S 4 at the most efficient switching frequency, that is, the resonant frequency of the LLC resonant circuit.
　仮に、図１において、ＨＶＤＣバス１０が双方向ＤＣ－ＤＣコンバータ３０とインバータ４０との接続点に接続されている場合、ＬＬＣ共振コンバータ３２がＨＶＤＣバス１０に接続される構成となる。この場合、ＬＬＣ共振コンバータ３２の出力電圧を目標値に近づける必要がある。ＬＬＣ共振コンバータ３２での変圧比は、トランスＴ１の巻数比により定まる。このため、ＬＬＣ共振コンバータ３２の出力電圧を目標値に近づける場合には、ＬＬＣ共振コンバータ３２はＰＦＭ制御により、出力電圧を調整する必要がある。この場合、ＬＬＣ共振コンバータ３２は、常に高効率に駆動ができない。 If the HVDC bus 10 is connected to the connection point between the bidirectional DC-DC converter 30 and the inverter 40 in FIG. 1, the LLC resonant converter 32 is connected to the HVDC bus 10. In this case, it is necessary to bring the output voltage of the LLC resonant converter 32 close to the target value. The transformation ratio in the LLC resonant converter 32 is determined by the turn ratio of the transformer T1. For this reason, when the output voltage of the LLC resonant converter 32 is brought close to the target value, the LLC resonant converter 32 needs to adjust the output voltage by PFM control. In this case, the LLC resonant converter 32 cannot always be driven with high efficiency.
　これに対し、本実施形態に係るエネルギーマネジメントシステム１では、ＨＶＤＣバス１０は、チョッパコンバータ３１とＬＬＣ共振コンバータ３２との接続点に接続された構成である。このため、チョッパコンバータ３１が出力電圧を調整すればよく、ＬＬＣ共振コンバータ３２は、出力電圧を調整する必要がない。その結果、ＬＬＣ共振コンバータ３２は、共振周波数をスイッチング周波数としてスイッチング素子３２Ｓ１～３２Ｓ４をスイッチング制御する高効率駆動が可能となる。 On the other hand, in the energy management system 1 according to the present embodiment, the HVDC bus 10 is configured to be connected to a connection point between the chopper converter 31 and the LLC resonant converter 32. For this reason, the chopper converter 31 only has to adjust the output voltage, and the LLC resonant converter 32 does not need to adjust the output voltage. As a result, the LLC resonant converter 32 can be driven with high efficiency by performing switching control of the switching elements 32S 1 to 32S 4 using the resonant frequency as a switching frequency.
　また、ＬＬＣ共振コンバータ３２は、エネルギーマネジメントシステム１の起動時であっても、高効率駆動が可能である。 Further, the LLC resonant converter 32 can be driven with high efficiency even when the energy management system 1 is activated.
　図４は、チョッパコンバータ３１とＬＬＣ共振コンバータ３２とに印加するゲート信号のタイムチャートを示す図である。 FIG. 4 is a diagram showing a time chart of the gate signal applied to the chopper converter 31 and the LLC resonant converter 32.
　図４の（１）は、チョッパコンバータ３１のスイッチング素子３１Ｓ１に印加するゲート信号のタイムチャートである。図４の（２）は、ＬＬＣ共振コンバータ３２のスイッチング素子３２Ｓ１，３２Ｓ４（又は３２Ｓ２，３２Ｓ３）に印加するゲート信号のタイムチャートである。また、図４の（３）は、ＨＶＤＣバス１０の電圧Ｖ１、（４）は双方向ＤＣ－ＤＣコンバータ３０からインバータ４０に印加される出力電圧Ｖ２（入出力端３２ＩＯ３、３２ＩＯ４の出力電圧。）を示す。 (1) in FIG. 4 is a time chart of the gate signal applied to the switching element 31S 1 of the chopper converter 31. (2) of FIG. 4 is a time chart of the gate signal applied to the switching elements 32S 1 and 32S 4 (or 32S 2 and 32S 3 ) of the LLC resonant converter 32. 4 is a voltage V1 of the HVDC bus 10, and (4) is an output voltage V2 applied to the inverter 40 from the bidirectional DC-DC converter 30 (output voltages of the input / output terminals 32IO 3 and 32IO 4 ). .)
　制御部３３は、チョッパコンバータ３１とＬＬＣ共振コンバータ３２とを同時に起動する。起動直後、制御部３３は、チョッパコンバータ３１をソフトスタート起動させる。これにより、図４（３）に示すように、チョッパコンバータ３１からの出力電圧、すなわち、ＨＶＤＣバス１０の電圧Ｖ１は緩やかに上昇する。この結果、ＬＬＣ共振コンバータ３２へ突入電流が流れ込むことを抑制できる。 The control unit 33 activates the chopper converter 31 and the LLC resonant converter 32 simultaneously. Immediately after startup, the control unit 33 soft-starts the chopper converter 31. As a result, as shown in FIG. 4 (3), the output voltage from the chopper converter 31, that is, the voltage V1 of the HVDC bus 10 rises gently. As a result, the inrush current can be prevented from flowing into the LLC resonant converter 32.
　突入電流を抑制することで、ＬＬＣ共振コンバータ３２を共振周波数近辺で高効率駆動させても、図４（４）に示すように、突入電流による高電圧は発生せず、ＨＶＤＣバス１０の電圧と同様に緩やかに上昇する。このため、制御部３３は、ＬＬＣ共振コンバータ３２を、起動直後から高効率に駆動させることができる。すなわち、制御部３３は、共振周波数をスイッチング周波数に設定して、スイッチング素子３２Ｓ１，３２Ｓ４と、スイッチング素子３２Ｓ２，３２Ｓ３とを、貫通電流が流れるのを防ぐための最小デッドタイムを除き、ほぼ５０％デューティでオンオフする。 By suppressing the inrush current, even if the LLC resonant converter 32 is driven with high efficiency near the resonance frequency, as shown in FIG. 4 (4), a high voltage due to the inrush current does not occur, and the voltage of the HVDC bus 10 Similarly, it rises moderately. For this reason, the control unit 33 can drive the LLC resonant converter 32 with high efficiency immediately after startup. That is, the control unit 33 sets the resonance frequency to the switching frequency, except for the minimum dead time for preventing the through current from flowing through the switching elements 32S 1 and 32S 4 and the switching elements 32S 2 and 32S 3. ON / OFF at about 50% duty.
　制御部３３は、チョッパコンバータ３１をソフトスタートさせて、チョッパコンバータ３１の出力電圧が目標値となると、ソフトスタートを終了し、出力電圧が目標値を維持するようＰＷＭ制御を行う。また、制御部３３は、チョッパコンバータ３１のソフトスタート終了後も、同じ周波数でＬＬＣ共振コンバータ３２を駆動し続ける。 The control unit 33 soft-starts the chopper converter 31, and when the output voltage of the chopper converter 31 reaches the target value, the control unit 33 ends the soft start and performs PWM control so that the output voltage maintains the target value. Further, the controller 33 continues to drive the LLC resonant converter 32 at the same frequency even after the soft start of the chopper converter 31 is completed.
　このように、本実施形態では、ＬＬＣ共振コンバータ３２は、起動直後から常時高効率駆動が可能となる。また、ＬＬＣ共振コンバータ３２への突入電流を抑制することで、ＬＬＣ共振コンバータ３２の各素子を、耐圧の高い素子にする必要がない。 Thus, in this embodiment, the LLC resonant converter 32 can always be driven with high efficiency immediately after startup. Further, by suppressing the inrush current to the LLC resonance converter 32, each element of the LLC resonance converter 32 does not need to be an element having a high withstand voltage.
　また、チョッパコンバータ３１をソフトスタートさせることで、ＬＬＣ共振コンバータ３２への突入電流を抑制しているが、チョッパコンバータ３１とＬＬＣ共振コンバータ３２とを同時起動させることで、ＬＬＣ共振コンバータ３２へ突入電流の流れ込みをより抑制できる。例えば、チョッパコンバータ３１を先に駆動させた場合、チョッパコンバータ３１のキャパシタ３１Ｃが充電された状態で、ＬＬＣ共振コンバータ３２が駆動することになる。この場合、キャパシタ３１Ｃの充電電圧によって、ＬＬＣ共振コンバータ３２に突入電流が流れ込むおそれがある。このため、チョッパコンバータ３１及びＬＬＣ共振コンバータ３２を同時に起動することで、突入電流の流れ込みを抑制できる。 In addition, the rush current to the LLC resonant converter 32 is suppressed by soft-starting the chopper converter 31, but the rush current to the LLC resonant converter 32 by simultaneously starting the chopper converter 31 and the LLC resonant converter 32. Can be further suppressed. For example, when the chopper converter 31 is driven first, the LLC resonant converter 32 is driven while the capacitor 31C of the chopper converter 31 is charged. In this case, an inrush current may flow into the LLC resonant converter 32 due to the charging voltage of the capacitor 31C. For this reason, the inrush current can be suppressed by simultaneously starting the chopper converter 31 and the LLC resonant converter 32.
　なお、本実施形態では、チョッパコンバータ３１とＬＬＣ共振コンバータ３２とを同時起動させているが、チョッパコンバータ３１を先に起動し後、チョッパコンバータ３１のソフトスタート期間中にＬＬＣ共振コンバータ３２を起動させるようにしてもよい。この場合であっても、キャパシタ３１Ｃは満充電はされていないため、突入電流を抑制できる。 In the present embodiment, the chopper converter 31 and the LLC resonant converter 32 are activated simultaneously. However, after the chopper converter 31 is activated first, the LLC resonant converter 32 is activated during the soft start period of the chopper converter 31. You may do it. Even in this case, since the capacitor 31C is not fully charged, the inrush current can be suppressed.
　また、本実施形態では、制御部３３は、チョッパコンバータ３１のソフトスタート開始時及び終了後のいずれも、同じ周波数でＬＬＣ共振コンバータ３２を駆動し続けているが、例えば、以下変形例のように、必ずしも、固定周波数でＬＬＣ共振コンバータ３２を駆動させ続けなくてもよい。 In the present embodiment, the control unit 33 continues to drive the LLC resonant converter 32 at the same frequency both at the start and after the soft start of the chopper converter 31. For example, as in the following modification example The LLC resonant converter 32 does not necessarily have to be continuously driven at a fixed frequency.
（変形例）
　図５は、ＬＬＣ共振コンバータの周波数特性を示す。横軸を「駆動周波数／共振周波数」とし、縦軸を「電圧利得（電圧ゲイン）」とする。また、図５では、軽負荷から重負荷までの４種類の負荷をそれぞれ別の曲線としてグラフ化している。 (Modification)
FIG. 5 shows the frequency characteristics of the LLC resonant converter. The horizontal axis is “drive frequency / resonance frequency”, and the vertical axis is “voltage gain (voltage gain)”. Further, in FIG. 5, four types of loads from light loads to heavy loads are graphed as separate curves.
　なお、「電圧利得」とは、入力電圧と出力電圧との比（出力電圧／入力電圧）を意味する。また、図５中の「Ｋ」は、ＬＬＣ共振コンバータの定常動作時（ソフトスタート終了後の通常動作時）における「電圧利得」の最小値を意味する。すなわち、この変形例において、ＬＬＣ共振コンバータは、通常動作時において、最も高効率となる周波数を含む所定の周波数範囲で駆動しており、「Ｋ」は、当該所定の周波数範囲において、「電圧利得」が最小値となる値を意味する。 “Voltage gain” means the ratio of the input voltage to the output voltage (output voltage / input voltage). Further, “K” in FIG. 5 means the minimum value of “voltage gain” at the time of steady operation of the LLC resonant converter (during normal operation after the end of soft start). That is, in this modification, the LLC resonant converter is driven in a predetermined frequency range including the frequency with the highest efficiency during normal operation, and “K” is “voltage gain” in the predetermined frequency range. "Means the minimum value.
　一般に定格負荷で駆動する場合、ＬＬＣ共振コンバータにおいては、駆動周波数を共振周波数近辺（理論上は「駆動周波数／共振周波数」＝１が最適となるが、実際には励磁インダクタンス等の影響があり、共振周波数より若干低い周波数が最適）とすることが効率面でも、最大電力を出力できる面においても適している。 In general, when driving with a rated load, in the LLC resonant converter, the drive frequency is near the resonance frequency (theoretically, “drive frequency / resonance frequency” = 1 is optimal, but in actuality, there is an influence such as excitation inductance, A frequency slightly lower than the resonance frequency is optimal) in terms of efficiency and output of maximum power.
　しかしながら、本変形例においては、ＬＬＣ共振コンバータにおける突入電流をさらに抑制するために、チョッパコンバータのソフトスタート期間中に、ＬＬＣ共振コンバータを電圧利得Ｋとなる周波数から駆動開始するようにしている。このように、最も高効率となる周波数ではなく、電圧利得Ｋとなる周波数から駆動開始するようにしているため、比較的高効率な周波数でＬＬＣ共振コンバータを駆動開始しつつも、突入電流も抑制することができる。 However, in this modification, in order to further suppress the inrush current in the LLC resonant converter, the LLC resonant converter is started to be driven from a frequency at which the voltage gain K is reached during the soft start period of the chopper converter. As described above, since the drive is started from the frequency at which the voltage gain K is obtained instead of the frequency at which the efficiency is highest, the inrush current is suppressed while the LLC resonant converter is started to be driven at a relatively high efficiency frequency. can do.
　そして、ソフトスタート終了後に、制御部は、より高効率となる周波数（共振周波数近辺）でＬＬＣ共振コンバータをスイッチング制御すればよい。このように、本変形例におけるＬＬＣ共振コンバータは、ソフトスタート期間、通常動作時双方において、常に、「Ｋ」以上の電圧利得となる周波数で駆動させるようにすることで、比較的高効率な周波数での駆動を維持しつつ、突入電流の抑制も図っている。 Then, after the soft start is completed, the control unit may perform switching control of the LLC resonant converter at a frequency (in the vicinity of the resonant frequency) with higher efficiency. As described above, the LLC resonant converter according to the present modification is driven at a frequency that provides a voltage gain of “K” or more at both the soft start period and the normal operation, so that a relatively high-efficiency frequency is achieved. The inrush current is also suppressed while maintaining the drive.
　なお、「Ｋ」はたとえば「駆動周波数／共振周波数」＝１となるときの電圧利得としてもよい。また、ＬＬＣ共振コンバータは「Ｋ」を超える電圧利得となる周波数から駆動開始するようにしてもよい。 Note that “K” may be a voltage gain when “drive frequency / resonance frequency” = 1, for example. Further, the LLC resonant converter may start to be driven from a frequency at which the voltage gain exceeds “K”.
　なお、上記した実施例はあくまで例であって、本発明の趣旨を逸脱しない範囲において種々の変更を加えることができる。また、各実施例の特徴部分、各要素を適宜組み合わせたり置き換えたりすることもできる。 The above-described embodiments are merely examples, and various modifications can be made without departing from the spirit of the present invention. Moreover, the characteristic part and each element of each embodiment can be appropriately combined or replaced.
Ｂ１…二次電池
Ｃｕ，Ｃｖ，Ｃｗ…キャパシタ
Ｌｍ…励磁インダクタンス
Ｌｕ，Ｌｖ，Ｌｗ…インダクタ
Ｓ１，Ｓ２…開閉器
Ｔ１…トランス
Ｕ，Ｖ，Ｗ…交流接続端
１…エネルギーマネジメントシステム
１０…ＨＶＤＣバス
２０…発電装置
２１…光発電パネル
２２…ＰＶコンバータ
２２Ｃ…コンデンサ
２２Ｄ…ダイオード
２２Ｉ１，２２Ｉ２…入力端
２２Ｌ…インダクタ
２２Ｏ１，２２Ｏ２…出力端
２２Ｓ…スイッチング素子
３０…ＤＣ－ＤＣコンバータ
３１…チョッパコンバータ
３１Ｃ…キャパシタ
３１ＩＯ１，３１ＩＯ２，３１ＩＯ３，３１ＩＯ４…入出力端
３１Ｌ…インダクタ
３１Ｓ１，３１Ｓ２…スイッチング素子
３２…ＬＬＣ共振コンバータ
３２Ｃ１，…共振用コンデンサ
３２Ｃ２…平滑コンデンサ
３２ＩＯ１，３２ＩＯ２，３２ＩＯ３，３２ＩＯ４…入出力端
３２Ｌ…共振用インダクタ
３２Ｓ１，３２Ｓ２，３２Ｓ３，３２Ｓ４…スイッチング素子
３２Ｓ５，３２Ｓ６，３２Ｓ７，３２Ｓ８…スイッチング素子
３３…制御部
４０…インバータ
４０ＩＯ１，４０ＩＯ２…入出力端
４０Ｓ１，４０Ｓ２，４０Ｓ３，４０Ｓ４，４０Ｓ５，４０Ｓ６…スイッチング素子
１０１…電力系統
１０２…分電盤 B1 ... Secondary batteries Cu, Cv, Cw ... Capacitor Lm ... Excitation inductances Lu, Lv, Lw ... Inductors S1, S2 ... Switch T1 ... Transformer U, V, W ... AC connection end 1 ... Energy management system 10 ... HVDC bus 20 ... power generator 21 ... photovoltaic panels 22 ... PV converter 22C ... capacitor 22D ... diodes 22I 1, 22I 2 ... inputs 22L ... inductor 22O 1, 22O 2 ... output terminal 22S ... switching device 30 ... DC-DC converter 31 ... chopper converter 31C ... capacitor 31IO 1, 31IO 2, 31IO 3 , 31IO 4 ... output terminal 31L ... inductor 31S 1, 31S 2 ... switching elements 32 ... LLC resonant converter 32C 1, ... resonant capacitor 32C 2 ... smoothing capacitor 32IO 1 32IO 2, 32IO 3, 32IO 4 ... output terminal 32L ... resonance inductor 32S 1, 32S 2, 32S 3 , 32S 4 ... switching elements 32S 5, 32S 6, 32S 7 , 32S 8 ... switching device 33 ... control unit 40 ... Inverters 40IO 1 , 40IO 2 ... Input / output terminals 40S 1 , 40S 2 , 40S 3 , 40S 4 , 40S 5 , 40S 6 ... Switching element 101 ... Power system 102 ... Distribution board

Claims (4)

  1. 　直流電圧バスと、
    　前記直流電圧バスに接続され、発電された電力を前記直流電圧バスへ出力する発電装置と、
    　前記直流電圧バスに接続された双方向ＤＣ－ＤＣコンバータ部と、
    　前記双方向ＤＣ－ＤＣコンバータ部に接続され、入力される交流電圧を直流電圧に変換し、前記双方向ＤＣ－ＤＣコンバータ部へ出力し、また、前記双方向ＤＣ－ＤＣコンバータ部から入力される直流電圧を交流電圧に変換するインバータと、
    　を備え、
    　前記双方向ＤＣ－ＤＣコンバータ部は、
    　二次電池接続部を有する非絶縁型のチョッパコンバータと、
    　前記チョッパコンバータと前記インバータとに接続された絶縁型の共振コンバータと、
    　を含み、
    　前記チョッパコンバータと前記共振コンバータとの接続点は、前記直流電圧バスに接続され、
    　前記チョッパコンバータは、
    　前記接続点から入力される直流電圧を変圧して前記二次電池接続部へ出力し、また、前記二次電池接続部から入力される直流電圧を変圧して前記接続点へ出力し、
    　前記共振コンバータは、
    　前記接続点から入力される直流電圧を変圧して前記インバータへ出力し、また、前記インバータから入力される直流電圧を変圧して前記接続点へ出力する、
    　エネルギーマネジメントシステム。     A DC voltage bus;
    A power generator connected to the DC voltage bus and outputting the generated power to the DC voltage bus;
    A bidirectional DC-DC converter connected to the DC voltage bus;
    Connected to the bidirectional DC-DC converter unit, converts an input AC voltage into a DC voltage, outputs it to the bidirectional DC-DC converter unit, and inputs from the bidirectional DC-DC converter unit An inverter that converts DC voltage to AC voltage;
    With
    The bidirectional DC-DC converter unit includes:
    A non-insulated chopper converter having a secondary battery connection;
    An isolated resonant converter connected to the chopper converter and the inverter;
    Including
    A connection point between the chopper converter and the resonant converter is connected to the DC voltage bus,
    The chopper converter is
    DC voltage input from the connection point is transformed and output to the secondary battery connection part, and DC voltage input from the secondary battery connection part is transformed and output to the connection point,
    The resonant converter is
    DC voltage input from the connection point is transformed and output to the inverter, and DC voltage input from the inverter is transformed and output to the connection point.
    Energy management system.
  2. 　前記チョッパコンバータ、及び前記共振コンバータはそれぞれ、スイッチング素子を有し、
    　前記チョッパコンバータ、及び前記共振コンバータを、スイッチング制御する制御部、をさらに備え、
    　前記制御部は、
    　前記双方向ＤＣ－ＤＣコンバータ部の起動時に、前記チョッパコンバータをソフトスタート起動させる、
    　請求項１に記載のエネルギーマネジメントシステム。     The chopper converter and the resonant converter each have a switching element,
    The chopper converter, and the resonant converter, further comprising a control unit for switching control,
    The controller is
    Soft-starting the chopper converter when starting the bidirectional DC-DC converter unit;
    The energy management system according to claim 1.
  3. 　前記制御部は、
    　前記双方向ＤＣ－ＤＣコンバータ部を起動して以降、固定周波数で前記共振コンバータをスイッチング制御する、
    　請求項２に記載のエネルギーマネジメントシステム。     The controller is
    Since the bidirectional DC-DC converter unit is started, the resonant converter is switching-controlled at a fixed frequency.
    The energy management system according to claim 2.
  4. 　前記制御部は、
    　前記チョッパコンバータ、及び前記共振コンバータを同時に起動する、
    　請求項２又は３に記載のエネルギーマネジメントシステム。     The controller is
    Simultaneously starting the chopper converter and the resonant converter;
    The energy management system according to claim 2 or 3.
PCT/JP2016/072888 2015-09-01 2016-08-04 Energy management system WO2017038363A1 (en)

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