WO2016017170A1 - Dc-dc converter - Google Patents

Dc-dc converter Download PDF

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Publication number
WO2016017170A1
WO2016017170A1 PCT/JP2015/003821 JP2015003821W WO2016017170A1 WO 2016017170 A1 WO2016017170 A1 WO 2016017170A1 JP 2015003821 W JP2015003821 W JP 2015003821W WO 2016017170 A1 WO2016017170 A1 WO 2016017170A1
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WO
WIPO (PCT)
Prior art keywords
voltage
control signal
circuit
switching circuit
converter
Prior art date
Application number
PCT/JP2015/003821
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French (fr)
Japanese (ja)
Inventor
裕 岩堀
Original Assignee
パナソニックＩｐマネジメント株式会社
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 パナソニックＩｐマネジメント株式会社 filed Critical パナソニックＩｐマネジメント株式会社
Priority to JP2016538154A priority Critical patent/JP6283888B2/en
Publication of WO2016017170A1 publication Critical patent/WO2016017170A1/en

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    • 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

Definitions

  • the present invention relates generally to DC-DC converters, and more particularly to DC-DC converters that perform voltage conversion in both directions.
  • the bi-directional DC-DC converter (hereinafter referred to as "the DC-DC converter according to the prior art 1") described in the document 1 includes a transformer, a primary side orthogonal transform unit, a secondary side orthogonal transform unit, and a booster circuit. Is equipped.
  • the power conversion circuit (hereinafter, “the DC-DC converter of the prior art 2”) described in the document 2 includes a two-stage transformer circuit and a control circuit.
  • the two-stage transformer circuit includes a chopper circuit and a bidirectional transformer circuit.
  • a conversion circuit (a transformer, a primary side orthogonal transformation unit and a secondary side orthogonal transformation unit) and a booster circuit are required. It will be provided with a two-stage circuit configuration. Therefore, it is difficult to perform voltage conversion in both directions only by the conversion circuit in the DC-DC converter of Conventional Example 1. Further, the DC-DC converter of Conventional Example 1 has a circuit configuration of two stages, so it is difficult to improve the conversion efficiency.
  • the DC-DC converter of the prior art example 2 when transforming from the first terminal to the second terminal, since the operation by the chopper circuit is not performed, the voltage in one direction is compared with the DC-DC converter of the prior art example 1. It is possible to improve conversion efficiency in conversion.
  • An object of the present invention is to provide a DC-DC converter capable of bi-directional voltage conversion and capable of improving conversion efficiency in bi-directional voltage conversion.
  • the DC-DC converter is a DC-DC converter that performs voltage conversion in both directions between the first DC voltage and the second DC voltage.
  • the DC-DC converter includes a first switching circuit including a first switching element, an inductor, a capacitor, and a transformer. Further, the DC-DC converter includes a second switching circuit having a second switching element, and a control circuit that controls the first switching circuit and the second switching circuit.
  • the first switching circuit is configured to perform voltage conversion between the first DC voltage and the first AC voltage in both directions.
  • the second switching circuit is configured to perform voltage conversion between a second AC voltage and the second DC voltage in both directions.
  • the transformer comprises a first winding and a second winding. The first winding and the second winding are magnetically coupled.
  • the first winding is electrically connected between the pair of connection ends on the first alternating voltage side in the first switching circuit.
  • the second winding is electrically connected between the pair of connection ends on the second AC voltage side in the second switching circuit.
  • a series circuit of the inductor and the capacitor is electrically connected in series with the first winding between the pair of connection ends in the first switching circuit.
  • FIG. 6 is a timing chart when converting a first DC voltage to a second DC voltage in the DC-DC converter of one embodiment.
  • FIG. FIG. 7 is a timing chart when converting a second DC voltage to a first DC voltage in the DC-DC converter of one embodiment.
  • FIG. FIG. 6 is an explanatory view for explaining an operation mode of a control circuit in the DC-DC converter of one embodiment.
  • FIG. 6 is a timing chart when converting a first DC voltage to a second DC voltage according to a first operation mode in the DC-DC converter of one embodiment.
  • FIG. FIG. 6 is a timing chart when the second DC voltage is converted to the first DC voltage according to the first operation mode in the DC-DC converter of the embodiment.
  • the DC-DC converter 10 is a DC-DC converter that performs voltage conversion between the first DC voltage Vd1 and the second DC voltage Vd2 in both directions.
  • the DC-DC converter 10 includes a switching circuit 1, an inductor L 1, a capacitor C 1, a transformer T 1, a switching circuit 2 and a control circuit 3.
  • the transformer T1 includes a first winding N11 and a second winding N12. The first winding N11 and the second winding N12 are magnetically coupled.
  • the switching circuit 1 corresponds to a first switching circuit. Further, in the DC-DC converter 10, the switching circuit 2 corresponds to a second switching circuit.
  • the switching circuit 1 is configured to perform voltage conversion between the first DC voltage Vd1 and the first AC voltage Va1 in both directions.
  • the switching circuit 1 is, for example, a full bridge circuit.
  • the switching circuit 1 includes a pair of connection ends 1a and 1b, a pair of connection ends 1c and 1d, and four switching elements Q1 to Q4.
  • the pair of connection ends 1 a and 1 b correspond to a pair of connection ends of the switching circuit 1 on the first DC voltage Vd 1 side.
  • the pair of connection ends 1 c and 1 d correspond to a pair of connection ends of the switching circuit 1 on the side of the first AC voltage Va 1.
  • each of the four switching elements Q1 to Q4 corresponds to a first switching element.
  • the storage battery 11 is electrically connected between the pair of connection ends 1a and 1b.
  • the connection end 1 a is electrically connected to the positive terminal of the storage battery 11.
  • the connection end 1 b is electrically connected to the negative terminal of the storage battery 11.
  • the inter-terminal voltage of the storage battery 11 is a first DC voltage Vd1.
  • a series circuit of an inductor L1, a capacitor C1 and a first winding N11 is electrically connected between the pair of connection ends 1c and 1d.
  • the first winding N11 is electrically connected between the pair of connection ends 1c and 1d.
  • the series circuit 4 of the inductor L1 and the capacitor C1 is electrically connected in series with the first winding N11 between the pair of connection ends 1c and 1d in the switching circuit 1.
  • the series circuit 4 constitutes a series resonant circuit.
  • Each of the four switching elements Q1 to Q4 is, for example, a normally-off n-channel MOSFET.
  • the diodes added to the four switching elements Q1 to Q4 in FIG. 1 are parasitic diodes.
  • the drain terminal of the switching element Q1 is electrically connected to the connection end 1a.
  • the source terminal of the switching element Q1 is electrically connected to the drain terminal of the switching element Q2.
  • the gate terminal of the switching element Q1 is electrically connected to the control circuit 3.
  • the drain terminal of the switching element Q2 is electrically connected to the connection end 1c.
  • the source terminal of the switching element Q2 is electrically connected to the connection end 1b.
  • the gate terminal of the switching element Q2 is electrically connected to the control circuit 3.
  • the drain terminal of the switching element Q3 is electrically connected to the drain terminal of the switching element Q1.
  • the source terminal of the switching element Q3 is electrically connected to the drain terminal of the switching element Q4.
  • the gate terminal of the switching element Q3 is electrically connected to the control circuit 3.
  • the drain terminal of the switching element Q4 is electrically connected to the connection end 1d.
  • the source terminal of the switching element Q4 is electrically connected to the source terminal of the switching element Q2.
  • the gate terminal of the switching element Q4 is electrically connected to the control circuit 3.
  • the switching circuit 1 is not limited to the full bridge circuit, but may be, for example, a half bridge circuit or a push-pull circuit.
  • the switching circuit 2 is configured to perform voltage conversion between the second AC voltage Va ⁇ b> 2 and the second DC voltage Vd ⁇ b> 2 in both directions.
  • the switching circuit 2 is, for example, a full bridge circuit.
  • the switching circuit 2 includes a pair of connection ends 2a and 2b, a pair of connection ends 2c and 2d, and four switching elements Q5 to Q8.
  • the pair of connection ends 2 a and 2 b correspond to a pair of connection ends of the switching circuit 2 on the side of the second AC voltage Va 2.
  • the pair of connection ends 2 c and 2 d correspond to a pair of connection ends of the switching circuit 2 on the second DC voltage Vd 2 side.
  • Each of the four switching elements Q5 to Q8 corresponds to a second switching element.
  • a second winding N12 is electrically connected between the pair of connection ends 2a and 2b.
  • a DC voltage source 12 is electrically connected between the pair of connection ends 2c and 2d.
  • the DC voltage source 12 is, for example, an electrolytic capacitor.
  • the connection end 2c is electrically connected to the terminal on the high potential side of the electrolytic capacitor.
  • the connection end 2d is electrically connected to the low potential side terminal of the electrolytic capacitor.
  • the inter-terminal voltage of the DC voltage source 12 is a second DC voltage Vd2.
  • the DC voltage source 12 is an electrolytic capacitor, it is not limited to this.
  • Each of the four switching elements Q5 to Q8 is, for example, a normally-off n-channel MOSFET.
  • the diodes added to the four switching elements Q5 to Q8 in FIG. 1 are parasitic diodes.
  • the drain terminal of the switching element Q5 is electrically connected to the drain terminal of the switching element Q7.
  • the source terminal of the switching element Q5 is electrically connected to the drain terminal of the switching element Q6.
  • the gate terminal of the switching element Q5 is electrically connected to the control circuit 3.
  • the drain terminal of the switching element Q6 is electrically connected to the connection end 2a.
  • the source terminal of the switching element Q6 is electrically connected to the source terminal of the switching element Q8.
  • the gate terminal of the switching element Q6 is electrically connected to the control circuit 3.
  • the drain terminal of the switching element Q7 is electrically connected to the connection end 2c.
  • the source terminal of the switching element Q7 is electrically connected to the drain terminal of the switching element Q8.
  • the gate terminal of the switching element Q7 is electrically connected to the control circuit 3.
  • the drain terminal of the switching element Q8 is electrically connected to the connection end 2b.
  • the source terminal of the switching element Q8 is electrically connected to the connection end 2d.
  • the gate terminal of the switching element Q8 is electrically connected to the control circuit 3.
  • the switching circuit 2 is not limited to the full bridge circuit, but may be, for example, a half bridge circuit or a push-pull circuit.
  • the control circuit 3 is configured to control the switching circuit 1 and the switching circuit 2.
  • the control circuit 3 is, for example, a microcomputer equipped with a program.
  • the control circuit 3 is not limited to a microcomputer, and may be, for example, a control IC.
  • the control circuit 3 is configured to control the switching circuit 1 by the first control signal. In other words, the control circuit 3 is configured to individually control the four switching elements Q1 to Q4 by the four first control signals.
  • the four first control signals are signals for controlling the corresponding four switching elements Q1 to Q4, respectively. That is, the control circuit 3 is configured to control the four switching elements Q1 to Q4 separately in the switching circuit 1.
  • Each of the four first control signals is, for example, a PWM signal.
  • control circuit 3 is configured to control the switching circuit 2 by the second control signal.
  • control circuit 3 is configured to separately control the four switching elements Q5 to Q8 by the four second control signals.
  • the four second control signals are signals for controlling the corresponding four switching elements Q5 to Q8. That is, the control circuit 3 is configured to separately control the four switching elements Q5 to Q8 in the switching circuit 2.
  • Each of the four second control signals is, for example, a PWM signal.
  • the frequencies of the four first control signals and the frequencies of the four second control signals are the same. Further, in the DC-DC converter 10, the duty ratio of each of the four first control signals and the duty ratio of each of the four second control signals are the same.
  • the control circuit 3 is also configured to synchronize the operation of the switching circuit 1 with the operation of the switching circuit 2.
  • the control circuit 3 is configured to synchronize the switching operation of each of the four switching elements Q1 to Q4 with the switching operation of each of the four switching elements Q5 to Q8.
  • the control circuit 3 is configured to simultaneously turn on the two switching elements Q1 and Q4 and the two switching elements Q5 and Q8.
  • the control circuit 3 changes the phase of the first control signal and the phase of the second control signal so as to make the phase difference Td (see FIGS. 2 and 3) between the first control signal and the second control signal variable. And are configured to adjust.
  • the horizontal axes in FIGS. 2 and 3 represent time axes.
  • the control circuit 3 when converting the first DC voltage Vd1 to the second DC voltage Vd2, the control circuit 3 switches the phase of the second control signal that controls the switching element Q5, as shown in FIG. The phase of the first control signal that controls the element Q1 is delayed. Further, as shown in FIG. 2, when converting the first DC voltage Vd1 to the second DC voltage Vd2, the control circuit 3 controls the phase of the second control signal that controls the switching element Q6 to control the switching element Q2. Delaying the phase of the first control signal.
  • Q1 to Q4 in FIG. 2 represent the waveforms of first control signals input to the switching elements Q1 to Q4, respectively.
  • Q5 to Q8 in FIG. 2 represent the waveforms of second control signals input to the switching elements Q5 to Q8, respectively.
  • the control circuit 3 controls the switching element Q1.
  • the phase is delayed relative to the phase of the second control signal that controls the switching element Q5.
  • the control circuit 3 controls the phase of the first control signal that controls the switching element Q2 to control the switching element Q6. Delaying the phase of the second control signal.
  • Q1 to Q4 in FIG. 3 represent the waveforms of the first control signals input to the switching elements Q1 to Q4, respectively.
  • Q5 to Q8 in FIG. 3 represent the waveforms of second control signals input to the switching elements Q5 to Q8, respectively.
  • phase of the first control signal controlling the switching element Q4 and the phase of the second control signal controlling the switching element Q8 controls the phase of the first control signal controlling the switching element Q1 and the switching element Q5 And the phase of the second control signal.
  • the relationship between the phase of the first control signal controlling the switching element Q3 and the phase of the second control signal controlling the switching element Q7 is the same as the phase of the first control signal controlling the switching element Q2, and the switching element Q6.
  • Vr in FIG. 2 represents the waveform of the resonant voltage generated in the series circuit 4.
  • Ir in FIG. 2 represents the waveform of the resonant current flowing in the series circuit 4.
  • IQ1 to IQ8 in FIG. 2 represent the waveforms of currents flowing through the switching elements Q1 to Q8.
  • Ia1 in FIG. 2 represents the waveform of the current output from the switching circuit 1.
  • Ia2 in FIG. 2 represents the waveform of the current input to the switching circuit 2.
  • the control circuit 3 controls the switching circuit 1 so that the two switching elements Q1 and Q4 and the two switching elements Q2 and Q3 are alternately turned on. Thereby, in the DC-DC converter 10, the switching circuit 1 operates as an inverter circuit that converts the first DC voltage Vd1 into the first AC voltage Va1.
  • the first alternating voltage Va1 from the switching circuit 1 is resonated by the series circuit 4, and the voltage resonated by the series circuit 4 is applied to the first winding N11 of the transformer T1.
  • the first induction voltage (second alternating voltage Va2) is generated in the second winding N12 of the transformer T1 according to the turns ratio of the transformer T1, and the second alternating voltage Va2 is switched to the switching circuit It becomes possible to input to 2.
  • the control circuit 3 delays the phase of each of the four second control signals more than the phase of each of the four first control signals. Further, the control circuit 3 controls the switching circuit 2 so that the two switching elements Q5 and Q8 and the two switching elements Q6 and Q7 are alternately turned on. Thus, in the DC-DC converter 10, it is possible to convert the second AC voltage Va2 input to the switching circuit 2 into a second DC voltage Vd2.
  • DC-DC converter 10 after first DC voltage Vd1 is converted to first AC voltage Va1 by switching circuit 1, second AC voltage Va2 can be converted to second DC voltage Vd2 by switching circuit 2. It becomes.
  • the first DC voltage Vd1 can be converted to the second DC voltage Vd2, and the second DC voltage Vd2 can be applied to the electrolytic capacitor which is the DC voltage source 12. It becomes.
  • the storage battery 11 can be discharged.
  • Vr in FIG. 3 represents the waveform of the resonant voltage generated in the series circuit 4.
  • Ir in FIG. 3 represents the waveform of the resonant current flowing in the series circuit 4.
  • IQ1 to IQ8 in FIG. 3 represent the waveforms of currents flowing through the switching elements Q1 to Q8.
  • Ia1 in FIG. 3 represents the waveform of the current input to the switching circuit 1.
  • Ia2 in FIG. 3 represents the waveform of the current output from the switching circuit 2.
  • the control circuit 3 controls the switching circuit 2 so that the two switching elements Q5 and Q8 and the two switching elements Q6 and Q7 are alternately turned on.
  • the switching circuit 2 operates as an inverter circuit that converts the second DC voltage Vd2 into the second AC voltage Va2. Therefore, in the DC-DC converter 10, it is possible to apply the second AC voltage Va2 converted by the switching circuit 2 to the second winding N12 of the transformer T1. As a result, in the DC-DC converter 10, a second induced voltage is generated in the first winding N11 of the transformer T1.
  • the second induced voltage generated in the first winding N11 of the transformer T1 is resonated by the series circuit 4, and the voltage (first alternating voltage Va1) resonated by the series circuit 4 is used as the switching circuit 1. It becomes possible to input.
  • the control circuit 3 delays the phase of each of the four first control signals more than the phase of each of the four second control signals. Further, the control circuit 3 controls the switching circuit 1 so that the two switching elements Q1 and Q4 and the two switching elements Q2 and Q3 are alternately turned on. Thereby, in the DC-DC converter 10, it becomes possible to convert the first AC voltage Va input to the switching circuit 1 into the first DC voltage Vd1.
  • the first AC voltage Va1 can be converted to the first DC voltage Vd1 by the switching circuit 1. It becomes.
  • the second DC voltage Vd2 can be converted to the first DC voltage Vd1
  • the first DC voltage Vd1 can be applied to the storage battery 11.
  • the storage battery 11 can be charged.
  • the control circuit 3 delays the phase of the second control signal more than the phase of the first control signal.
  • the current Ia1 output from the switching circuit 1 can be made larger than the current Ia2 input to the switching circuit 2. Therefore, in the DC-DC converter 10, it is possible to convert the first DC voltage Vd1 into the second DC voltage Vd2.
  • the control circuit 3 delays the phase of the first control signal more than the phase of the second control signal.
  • the current Ia2 output from the switching circuit 2 can be made larger than the current Ia1 input to the switching circuit 1. Therefore, in the DC-DC converter 10, it is possible to convert the second DC voltage Vd2 into the first DC voltage Vd1.
  • bidirectional voltage conversion can be performed with a simple configuration without using the booster circuit in the DC-DC converter of Conventional Example 1 or the chopper circuit in the DC-DC converter of Conventional Example 2. It becomes possible. As a result, in the DC-DC converter 10, the conversion efficiency can be improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Further, in the DC-DC converter 10, since the chopper circuit in the DC-DC converter of the prior art 2 becomes unnecessary, the conversion efficiency is improved in bidirectional voltage conversion as compared with the DC-DC converter of the prior art 2. Is possible. That is, in the DC-DC converter 10, voltage conversion can be performed bidirectionally, and conversion efficiency can be improved in bidirectional voltage conversion.
  • the phase of the first control signal and the phase of the second control signal are controlled so that the control circuit 3 changes the phase difference between the first control signal and the second control signal. Is configured to adjust.
  • the magnitude relationship between the first DC voltage Vd1 and the second DC voltage Vd2 can be appropriately changed. Therefore, in the DC-DC converter 10, regardless of the magnitude relationship between the turns ratio of the transformer T1 and the voltage conversion ratio for performing voltage conversion of the first DC voltage Vd1 and the second DC voltage Vd2 in both directions, It becomes possible to perform voltage conversion.
  • the conversion efficiency when converting the first DC voltage Vd1 to the second DC voltage Vd2 and the second DC voltage Vd2 to the first DC voltage Vd1 according to the voltage conversion ratio There may be a difference with the conversion efficiency of
  • the conversion efficiency when converting the first DC voltage Vd1 to the second DC voltage Vd2 is referred to as “first conversion efficiency” and the second DC voltage Vd2 is converted to the first DC voltage Vd1.
  • the conversion efficiency at the time is referred to as "second conversion efficiency”.
  • the inventor of the present application can suppress the difference between the first conversion efficiency and the second conversion efficiency by setting the turns ratio of the transformer T1 to the same ratio as the voltage conversion ratio. I got the knowledge that. However, in the DC-DC converter 10, since the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 respectively fluctuate within a predetermined range, the turns ratio of the transformer T1 and the voltage conversion ratio It is difficult to make the same ratio.
  • the turns ratio of the transformer T1 is smaller than a value obtained by dividing the maximum value of the first DC voltage Vd1 by the minimum value of the second DC voltage Vd2, and the minimum value of the first DC voltage Vd1 is equal to the second DC voltage Vd2. Preferably, it is greater than the value divided by the maximum value of.
  • the turns ratio of the transformer T1 is represented by a value obtained by dividing the number of turns of the first winding N11 by the number of turns of the second winding N12.
  • the turns ratio of the transformer T1 is obtained by dividing a voltage between terminals of the DC voltage source 12 by an average value of a voltage between terminals at charging in the storage battery 11 and a voltage at terminals in discharging the storage battery 11 as a reference value. It may be a value within a predetermined range.
  • the voltage conversion can be performed bidirectionally between the first DC voltage Vd1 and the second DC voltage Vd2 also by the turn ratio of the transformer T1.
  • the DC-DC converter 10 it is possible to suppress the difference between the first conversion efficiency and the second conversion efficiency.
  • the frequency of each of the first control signal and the second control signal is preferably equal to or higher than the resonant frequency of the series circuit 4.
  • the frequencies of the first control signal and the second control signal satisfy fffr.
  • the DC-DC converter 10 it is possible to suppress the hard switching operation of each of the four switching elements Q1 to Q4 and the four switching elements Q5 to Q8. Therefore, in the DC-DC converter 10, it is possible to suppress the switching loss. As a result, in the DC-DC converter 10, the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
  • the control circuit 3 preferably increases the frequency of each of the first control signal and the second control signal when the phase difference Td between the first control signal and the second control signal increases.
  • the absolute value of the voltage applied to the series circuit 4 increases.
  • energy transfer between the inductor L1 and the capacitor C1 is accelerated compared with the case where the phase difference Td between the first control signal and the second control signal is zero, and thus series The resonant frequency of the circuit 4 apparently increases.
  • the DC-DC converter 10 when the phase difference Td between the first control signal and the second control signal increases, the frequencies of the first control signal and the second control signal are increased. As a result, in the DC-DC converter 10, it is possible to suppress the hard switching operation of each of the four switching elements Q1 to Q4 and the four switching elements Q5 to Q8. Therefore, in the DC-DC converter 10, it is possible to suppress the switching loss. As a result, in the DC-DC converter 10, the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
  • the DC-DC converter 10 further includes a detection circuit 5 that detects the phase of the resonant current Ir flowing in the series circuit 4.
  • the detection circuit 5 includes a first detection unit 6 and a second detection unit 7.
  • the control circuit 3 determines the voltage phase between the pair of connection ends 1c and 1d or the voltage phase between the pair of connection ends 2a and 2b and the phase of the resonant current Ir.
  • the switching frequencies of the switching circuit 1 and the switching circuit 2 are controlled so that the phase difference is reduced.
  • the phase of the resonant current Ir flowing in the series circuit 4 is detected by the first detection unit 6 or the second detection unit 7.
  • the control circuit 3 performs switching when the phase of the resonance current Ir is in phase advance with respect to the voltage between the pair of connection ends 1c and 1d or the voltage between the pair of connection ends 2a and 2b.
  • the switching frequency of the circuit 1 and the switching circuit 2 is increased.
  • the control circuit 3 performs switching circuit 1 and switching The switching frequency of circuit 2 is reduced.
  • the switching frequencies of switching circuit 1 and switching circuit 2 are the same frequency.
  • the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
  • the phase of the voltage between the pair of connection ends to be subjected to the phase difference with the resonance current Ir be the phase of the voltage between the pair of connection ends in the switching circuit acting as the power supply side.
  • the phase of the voltage between the pair of connection ends to be the target be the phase of the voltage between the pair of connection ends 1c and 1d.
  • the phase of the voltage between the pair of connection ends to be a target be the phase of the voltage between the pair of connection ends 2a and 2b when power conversion is performed from the switching circuit 2 to the switching circuit 1.
  • the switching frequency means, for example, a frequency for switching the four switching elements Q1 to Q4 in the switching circuit 1.
  • the detection circuit 5 includes both the first detection unit 6 and the second detection unit 7
  • the detection circuit 5 may include only one of the first detection unit 6 and the second detection unit 7.
  • the DC-DC converter 10 includes the detection circuit 5, the detection circuit 5 may not be included.
  • the detection circuit 5 is configured to detect a detection current flowing through the switching circuit 1 (hereinafter, “first detection current”) and a detection current flowing through the switching circuit 2 (hereinafter, “second detection current”). Is preferred.
  • the first detection unit 6 is configured to detect the first detection current flowing to the switching circuit 1.
  • the second detection unit 7 is preferably configured to detect a second detection current flowing to the switching circuit 2.
  • the control circuit 3 sets the first control signal and the second control signal such that the difference between the first detection current or the second detection current detected by the detection circuit 5 and the set current preset by the operation unit becomes small.
  • it is configured to control the phase difference Td between them.
  • the control circuit 3 decreases the absolute value of the phase difference Td when the absolute value of the first detection current or the second detection current detected by the detection circuit 5 is larger than the absolute value of the set current. .
  • the control circuit 3 increases the absolute value of the phase difference Td.
  • the set current is stored in the storage unit 3 a of the microcomputer, which is the control circuit 3.
  • the control circuit 3 compares the set current stored in the storage unit 3a with the first detection current or the second detection current detected by the detection circuit 5, and based on the calculation result, the first control signal and A second control signal is configured to be generated.
  • the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 may fluctuate outside the allowable range.
  • the allowable range is a range in which the first DC voltage Vd1 and the second DC voltage Vd2 are allowed to fluctuate. That is, in the DC-DC converter 10, the voltage ratio between the first DC voltage Vd1 and the second DC voltage Vd2 may deviate from the turns ratio of the transformer T1, and the operation may become unstable.
  • the detection circuit 5 is preferably configured to detect the first DC voltage Vd1 and the second DC voltage Vd2.
  • the detection circuit 5 includes a third detection unit 8 and a fourth detection unit 9.
  • the third detection unit 8 is configured to detect the first DC voltage Vd1.
  • the fourth detection unit 9 is configured to detect the second DC voltage Vd2.
  • the third detection unit 8 and the fourth detection unit 9 are electrically connected to the control circuit 3.
  • the control circuit 3 is configured to calculate a voltage ratio between the first DC voltage Vd1 and the second DC voltage Vd2 based on the first DC voltage Vd1 and the second DC voltage Vd2 detected by the detection circuit 5. Is preferred.
  • the control circuit 3 has a first operation mode and a second operation mode as specific operation modes for performing specific control different from the above-described control (normal control). .
  • the control circuit 3 delays the phase of one of the first control signal and the second control signal more than the other phase of the first control signal and the second control signal.
  • 1 means controlling the switching circuit 1 and the second switching circuit 2 (area A1 in FIG. 4).
  • an operation mode for performing normal control is referred to as a "normal operation mode".
  • the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 so as to be in a prescribed state described later.
  • the prescribed state one of the phases of the first control signal and the second control signal is delayed relative to the other phase of the first control signal and the second control signal, and the other is in the on state.
  • One is in the off state (see FIGS. 5 and 6).
  • FIG. 5 shows a timing chart when the first DC voltage Vd1 is converted to the second DC voltage Vd2 in the DC-DC converter 10.
  • FIG. 6 shows a timing chart when the second DC voltage Vd2 is converted into the first DC voltage Vd1 in the DC-DC converter 10.
  • the horizontal axes in FIGS. 5 and 6 represent time axes.
  • the control circuit 3 delays the phase of the second control signal relative to the phase of the first control signal, and the second control signal is in the on state.
  • the switching circuit 1 and the switching circuit 2 are controlled so that the control signal is turned off.
  • the first switching circuit 1 and the first switching circuit 1 are configured such that the control circuit 3 delays the one phase more than the other phase, and the other duty ratio is smaller than the one duty ratio.
  • the second switching circuit 2 is controlled (see FIGS. 7 and 8).
  • FIG. 7 is a timing chart when the first DC voltage Vd1 is converted to the second DC voltage Vd2 in the DC-DC converter 10.
  • FIG. 8 shows a timing chart when the second DC voltage Vd2 is converted into the first DC voltage Vd1 in the DC-DC converter 10.
  • the horizontal axes in FIGS. 7 and 8 represent time axes.
  • control circuit 3 delays the phase of the second control signal from the phase of the first control signal, and the duty ratio of the first control signal is the second control signal.
  • the switching circuit 1 and the switching circuit 2 are controlled to be smaller than the duty ratio of The duty ratio of the first control signal is less than 50%.
  • Control circuit 3 changes the duty ratio of the first control signal when changing the operation mode, for example, from the second operation mode (A5 area in FIG. 4) to the first operation mode (A3 area in FIG. 4).
  • the duty ratio of the second control signal is made several percent (within the range of 0% to 5%) in proportion to the phase difference Td.
  • the control circuit 3 changes the operation mode, for example, from the second operation mode (A5 area in FIG. 4) to the normal operation mode (right side area in A1 area in FIG.
  • Control circuit 3 changes the duty ratio of the second control signal when changing the operation mode, for example, from the second operation mode (A4 area in FIG. 4) to the first operation mode (A2 area in FIG. 4).
  • the duty ratio of the first control signal is made several percent (within the range of 0% to 5%) in proportion to the phase difference Td.
  • the control circuit 3 changes the operation mode, for example, from the second operation mode (A4 area in FIG. 4) to the normal operation mode (left side area of A1 area in FIG. 4)
  • the second control signal The duty ratio of the first control signal is made 50% in proportion to the phase difference Td.
  • control circuit 3 can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the first operation mode. Further, the control circuit 3 can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the normal operation mode. As a result, in the DC-DC converter 10, when the operation mode is switched by the control circuit 3, it is possible to avoid a sudden change in the output waveform, and it becomes possible to stabilize the operation of the DC-DC converter 10.
  • a first set voltage ratio Ra1 (see FIG. 4) and a second set voltage ratio Ra2 (see FIG. 4) are stored.
  • Each of 1st setting voltage ratio Ra1 and 2nd setting voltage ratio Ra2 is a voltage ratio for comparing with the said voltage ratio.
  • the second set voltage ratio Ra2 is larger than the first set voltage ratio Ra1.
  • the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the first operation mode under a first condition described later.
  • the first condition is that the voltage ratio is smaller than the first set voltage ratio Ra1 and the second DC voltage Vd2 is converted to the first DC voltage Vd1 (during charging) (area A2 in FIG. 4). .
  • control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the first operation mode under the second condition described later.
  • the second condition is that the voltage ratio is larger than the second set voltage ratio Ra2 and the first DC voltage Vd1 is converted to the second DC voltage Vd2 (during discharge) (area A3 in FIG. 4). .
  • the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the second operation mode under a third condition described later.
  • a third condition is when the voltage ratio is smaller than the first set voltage ratio Ra1 and the first DC voltage Vd1 is converted to the second DC voltage Vd2 (during discharge) and the absolute value of the set current described above This is when the value is equal to or less than the predetermined value (area A4 in FIG. 4).
  • control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the second operation mode under a fourth condition described later.
  • a fourth condition is that when the voltage ratio is larger than the second set voltage ratio Ra2 and the second DC voltage Vd2 is converted to the first DC voltage Vd1 (during charging), the absolute value of the set current is It is the time below the above-mentioned predetermined value (area A5 in FIG. 4).
  • the control circuit 3 is not limited to the normal operation mode, and the first switching circuit 1 and the second switching circuit 2 are selected according to one of the first operation mode and the second operation mode. Is configured to control. Thereby, in the DC-DC converter 10, the operation can be stabilized even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 fluctuate out of the allowable range. .
  • control circuit 3 controls first switching circuit 1 and second switching circuit 2 in the second operation mode
  • the condition is taken that the absolute value of the set current is equal to or less than the predetermined value, but this condition is limited. Absent.
  • control circuit 3 controls first switching circuit 1 and second switching circuit 2 in the second operation mode, power obtained by the product of one of first DC voltage Vd1 and second DC voltage Vd2 and a set current
  • the condition may be that the absolute value of is less than or equal to the predetermined value. Further, when the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 in the second operation mode, the absolute value of the phase difference Td between the first control signal and the second control signal is not
  • the condition may be a time less than or equal to a predetermined value.
  • control circuit 3 has both of the first operation mode and the second operation mode as an operation mode
  • the present invention is not limited to this, and has one of the first operation mode and the second operation mode. It may be
  • the storage battery 11 is electrically connected between the pair of connection ends 1a and 1b, and the DC voltage source 12 is electrically connected between the pair of connection ends 2c and 2d. Not exclusively.
  • the DC voltage source 12 may be electrically connected between the pair of connection ends 1a and 1b, and the storage battery 11 may be electrically connected between the pair of connection ends 2c and 2d.
  • the DC-DC converter (10) is a voltage in which the first DC voltage (Vd1) and the second DC voltage (Vd2) are bidirectionally supplied. It is a DC-DC converter that performs conversion.
  • the DC-DC converter (10) includes a first switching circuit (1) including a first switching element (Q1), an inductor (L1), a capacitor (C1), and a transformer (T1). Further, the DC-DC converter (10) comprises a second switching circuit (2) having a second switching element (Q5), and a control circuit for controlling the first switching circuit (1) and the second switching circuit (2). And (3) are provided.
  • the first switching circuit (1) is configured to perform voltage conversion between the first DC voltage (Vd1) and the first AC voltage (Va1) in both directions.
  • the second switching circuit (2) is configured to perform voltage conversion between the second AC voltage (Va2) and the second DC voltage (Vd2) in both directions.
  • the transformer (T1) includes a first winding (N11) and a second winding (N12).
  • the first winding (N11) and the second winding (N12) are magnetically coupled.
  • a first winding (N11) is electrically connected between the pair of connection ends (1c, 1d) on the first AC voltage (Va1) side in the first switching circuit (1).
  • a second winding (N12) is electrically connected between the pair of connection ends (2a, 2b) on the second AC voltage (Va2) side in the second switching circuit (2).
  • the series circuit of the inductor (L1) and the capacitor (C1) is electrically connected in series with the first winding (N11) between the pair of connection ends (1c, 1d) in the first switching circuit (1). There is.
  • the DC-DC converter (10) does not use the booster circuit in the DC-DC converter of Conventional Example 1 or the chopper circuit in the DC-DC converter of Conventional Example 2 and has a simple configuration. It is possible to perform voltage conversion in the As a result, in the DC-DC converter (10), it is also possible to improve the conversion efficiency as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Further, in the DC-DC converter (10), since the chopper circuit in the DC-DC converter of Conventional Example 2 becomes unnecessary, the conversion efficiency is improved in bidirectional voltage conversion as compared with the DC-DC converter of Conventional Example 2. It is possible to That is, in the DC-DC converter (10), voltage conversion can be performed bidirectionally, and conversion efficiency can be improved in bidirectional voltage conversion.
  • the number of turns of the first winding (N11) is divided by the number of turns of the second winding (N12)
  • the turns ratio of the transformer (T1) represented by the value is smaller than a value obtained by dividing the maximum value of the first DC voltage (Vd1) by the minimum value of the second DC voltage (Vd2), and the first DC voltage It is preferable that the minimum value of Vd1) be larger than a value obtained by dividing the minimum value of the second DC voltage (Vd2).
  • the voltage value of the first DC voltage (Vd1) and the voltage value of the second DC voltage (Vd2) each fluctuate within a predetermined range. Even if there is, it is possible to suppress the difference between the first conversion efficiency and the second conversion efficiency.
  • one of the first DC voltage (Vd1) and the second DC voltage (Vd2) is a terminal of the storage battery (11) It is preferable to be an inter-voltage.
  • the other of the first DC voltage (Vd1) and the second DC voltage (Vd2) is a voltage between terminals of the DC voltage source (12).
  • the turns ratio of the transformer (T1) is obtained by dividing the inter-terminal voltage of the DC voltage source (12) by the average value of the inter-terminal voltage during charging in the storage battery (11) and the inter-terminal voltage during discharging in the storage battery (11). It is preferable that it is a value within a predetermined range in which the obtained value is a reference value.
  • the DC-DC converter (10) can suppress the difference between the first conversion efficiency and the second conversion efficiency.
  • the control circuit (3) comprises a first switching element (Q1).
  • the first switching circuit (1) is configured to be controlled by the first control signal to be controlled.
  • the control circuit (3) is preferably configured to control the second switching circuit 2 by a second control signal that controls the second switching element (Q5).
  • each of the first control signal and the second control signal is a PWM signal. It is preferable that the first control signal and the second control signal have the same frequency and the same duty ratio.
  • the control circuit (3) adjusts the phase of the first control signal and the phase of the second control signal so as to make the phase difference (Td) between the first control signal and the second control signal variable. It is preferable to be configured.
  • voltage conversion can be performed bidirectionally between the first DC voltage (Vd1) and the second DC voltage (Vd2). Further, in the DC-DC converter (10), voltage conversion is performed bidirectionally with a simple configuration without using the booster circuit in the DC-DC converter of Conventional Example 1 or the chopper circuit in the DC-DC converter of Conventional Example 2. It becomes possible. As a result, in the DC-DC converter (10), the conversion efficiency can be improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
  • the conversion efficiency is improved in bidirectional voltage conversion as compared with the DC-DC converter of Conventional Example 2. It is possible to That is, in the DC-DC converter (10), voltage conversion can be performed bidirectionally, and conversion efficiency can be improved in bidirectional voltage conversion.
  • the control circuit (3) controls one of the phases of the first control signal and the second control signal as the first control. Preferably, it is configured to lag behind the other phase of the signal and the second control signal.
  • voltage conversion can be performed bidirectionally between the first DC voltage (Vd1) and the second DC voltage (Vd2).
  • each frequency of the first control signal and the second control signal is equal to or higher than the resonance frequency of the series circuit (4). Is preferred.
  • the sixth aspect in the DC-DC converter (10), hard switching operation of each of the first switching element (Q1) and the second switching element (Q5) can be suppressed. Therefore, in the DC-DC converter (10), it is possible to suppress the switching loss. As a result, in the DC-DC converter (10), the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
  • the control circuit (3) controls the difference between the first control signal and the second control signal.
  • the phase difference (Td) increases, it is preferable to increase the frequency of each of the first control signal and the second control signal.
  • the DC-DC converter (10) can suppress the switching loss.
  • the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
  • the DC-DC converter (10) is a series circuit (4). It is preferable to further include a detection circuit (5) for detecting the phase of the flowing resonance current (Ir).
  • the control circuit (3) is responsive to the phase of the resonant current (Ir) detected by the detection circuit (5), between the pair of connection ends (1c, 1d) in the first switching circuit (1) or the second switching circuit
  • the first switching circuit (1) and the second switching circuit (2) are arranged such that the phase difference between the phase of the voltage between the pair of connection ends (2a, 2b) in (2) and the phase of the resonant current (Ir) is reduced.
  • the switching frequency of 2) is controlled.
  • the DC-DC converter (10) can further improve the conversion efficiency as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. .
  • the detection circuit (5) detects a detection current flowing through the first switching circuit (1) or the second switching circuit (2).
  • the control circuit (3) sets the phase difference between the first control signal and the second control signal such that the difference between the detection current detected by the detection circuit (5) and the preset setting current is reduced.
  • it is configured to control
  • the DC-DC converter (10) can further improve the conversion efficiency as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Become.
  • the detection circuit (5) detects the first DC voltage (Vd1) and the second DC voltage (Vd2). It is preferable to be configured.
  • the control circuit (3) generates a first DC voltage (Vd1) and a second DC voltage (Vd2) based on the first DC voltage (Vd1) and the second DC voltage (Vd2) detected by the detection circuit (5). Preferably, it is configured to calculate a voltage ratio of
  • the control circuit (3) preferably has a specific operation mode for performing specific control. In the specific operation mode, the control circuit (3) delays the phase of the second control signal relative to the phase of the first control signal, and the second control signal is turned off when the first control signal is on.
  • the first switching circuit (1) and the second switching circuit (2) are controlled. It is preferable that a first set voltage ratio and a second set voltage ratio larger than the first set voltage ratio be stored in the storage unit provided in the control circuit (3).
  • the control circuit (3) sets the second voltage ratio to the second set voltage ratio.
  • the first switching circuit (1) and the second switching circuit (2) are controlled according to the specific operation mode, each being larger than and converting from the first DC voltage (Vd1) to the second DC voltage (Vd2) Is preferred.
  • the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to stabilize the That is, in the DC-DC converter 10, there is no restriction on the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate, and the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate is expanded. It will be possible to
  • the control circuit (3) has a second operation mode different from the first operation mode which is the specific operation mode. Is preferred. In the second operation mode, the control circuit (3) delays the phase of the second control signal relative to the phase of the first control signal, and the duty ratio of the first control signal is smaller than the duty ratio of the second control signal To control the first switching circuit (1) and the second switching circuit (2).
  • the control circuit (3) When the voltage ratio is smaller than the first set voltage ratio and the first direct current voltage (Vd1) is converted to the second direct current voltage (Vd2), the control circuit (3) generates the second set voltage ratio as the second set voltage ratio.
  • the setting current, the first DC voltage (Vd1) and the second DC voltage (Vd2) are larger than the above and when converting from the second DC voltage (Vd2) to the first DC voltage (Vd1).
  • the second operation mode Preferably, the first switching circuit (1) and the second switching circuit (2) are controlled.
  • the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to make it more stable. Therefore, in the DC-DC converter 10, it is possible to further extend the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate.
  • the duty ratio of the first control signal is a phase difference (Td) between the first control signal and the second control signal. It is preferable to be proportional to
  • the control circuit (3) in the DC-DC converter (10), the control circuit (3) generates the waveforms of the first control signal and the second control signal when switching from the second operation mode to the first operation mode. It becomes possible to match. Further, the control circuit (3) can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the normal operation mode. As a result, in the DC-DC converter (10), it is possible to avoid a sudden change in the output waveform when the operation mode is switched by the control circuit (3), and the operation of the DC-DC converter (10) is stabilized. It becomes possible.
  • the detection circuit (5) detects the first DC voltage (Vd1) and the second DC voltage (Vd2). It is preferable to be configured.
  • the control circuit (3) generates a first DC voltage (Vd1) and a second DC voltage (Vd2) based on the first DC voltage (Vd1) and the second DC voltage (Vd2) detected by the detection circuit (5). Preferably, it is configured to calculate a voltage ratio of
  • the control circuit (3) preferably has a specific operation mode for performing specific control. In the specific operation mode, the control circuit (3) delays the phase of the first control signal relative to the phase of the second control signal, and the first control signal is turned off when the second control signal is on.
  • the first switching circuit (1) and the second switching circuit (2) are controlled. It is preferable that a first set voltage ratio and a second set voltage ratio larger than the first set voltage ratio be stored in the storage unit provided in the control circuit (3).
  • the control circuit (3) sets the second voltage ratio to the second set voltage ratio.
  • the first switching circuit (1) and the second switching circuit (2) are controlled according to the specific operation mode, each being larger than and converting from the first DC voltage (Vd1) to the second DC voltage (Vd2) Is preferred.
  • the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to stabilize the That is, in the DC-DC converter 10, there is no restriction on the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate, and the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate is expanded. It will be possible to
  • the control circuit (3) has a second operation mode different from the first operation mode which is the specific operation mode. Is preferred. In the second operation mode, the control circuit (3) delays the phase of the first control signal relative to the phase of the second control signal, and the duty ratio of the second control signal is smaller than the duty ratio of the first control signal To control the first switching circuit (1) and the second switching circuit (2).
  • the control circuit (3) When the voltage ratio is smaller than the first set voltage ratio and the first direct current voltage (Vd1) is converted to the second direct current voltage (Vd2), the control circuit (3) generates the second set voltage ratio as the second set voltage ratio.
  • the setting current, the first DC voltage (Vd1) and the second DC voltage (Vd2) are larger than the above and when converting from the second DC voltage (Vd2) to the first DC voltage (Vd1).
  • the second operation mode Preferably, the first switching circuit (1) and the second switching circuit (2) are controlled.
  • the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to make it more stable. Therefore, in the DC-DC converter 10, it is possible to further extend the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate.
  • the duty ratio of the second control signal is a phase difference (Td) between the first control signal and the second control signal. It is preferable to be proportional to
  • the control circuit (3) in the DC-DC converter (10), the control circuit (3) generates the waveforms of the first control signal and the second control signal when switching from the second operation mode to the first operation mode. It becomes possible to match. Further, the control circuit (3) can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the normal operation mode. As a result, in the DC-DC converter (10), it is possible to avoid a sudden change in the output waveform when the operation mode is switched by the control circuit (3), and the operation of the DC-DC converter (10) is stabilized. It becomes possible.

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  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

　The present invention addresses the problem of providing a DC-DC converter with which it is possible to perform voltage conversion bidirectionally and improve conversion efficiency. The DC-DC converter (10) pertaining to the present invention is provided with a switching circuit (1), an inductor (L1), a capacitor (C1), a transformer (T1), a switching circuit (2), and a control circuit (3). A first winding (N11) is electrically connected between a pair of connection ends (1c, 1d) of the switching circuit (1). A serial circuit (4) of the inductor (L1) and the capacitor (C1) is electrically connected in series between the connection ends (1c, 1d), to the first winding (N11).

Description

ＤＣ－ＤＣコンバータDC-DC converter
　本発明は、一般に、ＤＣ－ＤＣコンバータに関し、より詳細には、双方向に電圧変換を行うＤＣ－ＤＣコンバータに関する。 The present invention relates generally to DC-DC converters, and more particularly to DC-DC converters that perform voltage conversion in both directions.
　従来、高電圧の第１バッテリと、低電圧の第２バッテリとの間で変圧可能な双方向ＤＣ－ＤＣコンバータが提案されている（文献１［日本国公開特許公報第２００９－１７７９４０号］参照）。 Heretofore, a bidirectional DC-DC converter that can be transformed between a high voltage first battery and a low voltage second battery has been proposed (see Document 1 [Japanese Patent Application Publication 2009-177940]). ).
　文献１に記載された双方向ＤＣ－ＤＣコンバータ（以下、「従来例１のＤＣ－ＤＣコンバータ」）は、トランスと、１次側直交変換部と、２次側直交変換部と、昇圧回路とを備えている。 The bi-directional DC-DC converter (hereinafter referred to as "the DC-DC converter according to the prior art 1") described in the document 1 includes a transformer, a primary side orthogonal transform unit, a secondary side orthogonal transform unit, and a booster circuit. Is equipped.
　また、従来、第１端子と第２端子との間において双方向に変圧を行う電力変換回路が提案されている（文献２［日本国公開特許公報第２０１４－５７３８７号］参照）。 Also, conventionally, there has been proposed a power conversion circuit that performs transformation in both directions between the first terminal and the second terminal (refer to Document 2 [Japanese Patent Application Publication No. 2014-57387]).
　文献２に記載された電力変換回路（以下、「従来例２のＤＣ－ＤＣコンバータ」）は、２段式変圧回路と、制御回路とを備えている。２段式変圧回路は、チョッパ回路と、双方向変圧回路とを備えている。 The power conversion circuit (hereinafter, “the DC-DC converter of the prior art 2”) described in the document 2 includes a two-stage transformer circuit and a control circuit. The two-stage transformer circuit includes a chopper circuit and a bidirectional transformer circuit.
　従来例２のＤＣ－ＤＣコンバータでは、第１端子から第２端子への変圧のとき、チョッパ回路による動作を行わず、双方向変圧回路に設けられたトランスを用いて変圧を行う。また、従来例２のＤＣ－ＤＣコンバータでは、第２端子から第１端子への変圧のとき、チョッパ回路による動作を行い、チョッパ回路および上記トランスを用いて変圧を行う。 In the DC-DC converter of Conventional Example 2, when transforming from the first terminal to the second terminal, the operation by the chopper circuit is not performed, and the transformation is performed using the transformer provided in the bidirectional transformation circuit. Further, in the DC-DC converter of Conventional Example 2, when transforming from the second terminal to the first terminal, operation is performed by the chopper circuit, and transformation is performed using the chopper circuit and the transformer.
　ところで、従来例１のＤＣ－ＤＣコンバータでは、双方向に電圧変換を行うために、変換回路（トランス、１次側直交変換部および２次側直交変換部）と、昇圧回路とが必要となり、２段の回路構成を備えることになる。そのため、従来例１のＤＣ－ＤＣコンバータにおける変換回路だけでは、双方向に電圧変換を行うことが難しい。また、従来例１のＤＣ－ＤＣコンバータでは、２段の回路構成を備えることになるため、変換効率を向上させることが難しい。 By the way, in the DC-DC converter of Conventional Example 1, in order to perform voltage conversion in both directions, a conversion circuit (a transformer, a primary side orthogonal transformation unit and a secondary side orthogonal transformation unit) and a booster circuit are required. It will be provided with a two-stage circuit configuration. Therefore, it is difficult to perform voltage conversion in both directions only by the conversion circuit in the DC-DC converter of Conventional Example 1. Further, the DC-DC converter of Conventional Example 1 has a circuit configuration of two stages, so it is difficult to improve the conversion efficiency.
　また、従来例２のＤＣ－ＤＣコンバータでは、第１端子から第２端子への変圧のとき、チョッパ回路による動作を行わないため、従来例１のＤＣ－ＤＣコンバータに比べて、一方向の電圧変換において変換効率を向上させることが可能となる。 Further, in the DC-DC converter of the prior art example 2, when transforming from the first terminal to the second terminal, since the operation by the chopper circuit is not performed, the voltage in one direction is compared with the DC-DC converter of the prior art example 1. It is possible to improve conversion efficiency in conversion.
　しかしながら、従来例２のＤＣ－ＤＣコンバータでは、第２端子から第１端子への変圧のとき、チョッパ回路による動作を行うため、双方向の電圧変換において変換効率を向上させることが難しい。また、従来例２のＤＣ－ＤＣコンバータでも、２段の回路構成（チョッパ回路および双方向変圧回路）を備えることになるため、変換効率を向上させることが難しい。 However, in the DC-DC converter of Conventional Example 2, since the operation by the chopper circuit is performed at the time of transformation from the second terminal to the first terminal, it is difficult to improve the conversion efficiency in bidirectional voltage conversion. Further, even the DC-DC converter of Conventional Example 2 is provided with a two-stage circuit configuration (chopper circuit and bidirectional transformer circuit), so it is difficult to improve the conversion efficiency.
　本発明の目的は、双方向に電圧変換を行うことが可能で、かつ、双方向の電圧変換において変換効率を向上させることが可能なＤＣ－ＤＣコンバータを提供することである。 An object of the present invention is to provide a DC-DC converter capable of bi-directional voltage conversion and capable of improving conversion efficiency in bi-directional voltage conversion.
　本発明に係る一態様のＤＣ－ＤＣコンバータは、第１直流電圧と第２直流電圧とを双方向に電圧変換を行うＤＣ－ＤＣコンバータである。前記ＤＣ－ＤＣコンバータは、第１スイッチング素子を具備する第１スイッチング回路と、インダクタと、コンデンサと、トランスとを備えている。また、前記ＤＣ－ＤＣコンバータは、第２スイッチング素子を具備する第２スイッチング回路と、前記第１スイッチング回路および前記第２スイッチング回路を制御する制御回路とを備えている。前記第１スイッチング回路は、前記第１直流電圧と第１交流電圧とを双方向に電圧変換を行うように構成されている。前記第２スイッチング回路は、第２交流電圧と前記第２直流電圧とを双方向に電圧変換を行うように構成されている。前記トランスは、第１巻線と第２巻線とを備えている。前記第１巻線と前記第２巻線とは、磁気的に結合されている。前記第１スイッチング回路における前記第１交流電圧側の一対の接続端間には、前記第１巻線が電気的に接続されている。前記第２スイッチング回路における前記第２交流電圧側の一対の接続端間には、前記第２巻線が電気的に接続されている。前記インダクタと前記コンデンサとの直列回路は、前記第１スイッチング回路における前記一対の接続端間において、前記第１巻線と電気的に直列接続されている。 The DC-DC converter according to one aspect of the present invention is a DC-DC converter that performs voltage conversion in both directions between the first DC voltage and the second DC voltage. The DC-DC converter includes a first switching circuit including a first switching element, an inductor, a capacitor, and a transformer. Further, the DC-DC converter includes a second switching circuit having a second switching element, and a control circuit that controls the first switching circuit and the second switching circuit. The first switching circuit is configured to perform voltage conversion between the first DC voltage and the first AC voltage in both directions. The second switching circuit is configured to perform voltage conversion between a second AC voltage and the second DC voltage in both directions. The transformer comprises a first winding and a second winding. The first winding and the second winding are magnetically coupled. The first winding is electrically connected between the pair of connection ends on the first alternating voltage side in the first switching circuit. The second winding is electrically connected between the pair of connection ends on the second AC voltage side in the second switching circuit. A series circuit of the inductor and the capacitor is electrically connected in series with the first winding between the pair of connection ends in the first switching circuit.
一実施形態のＤＣ－ＤＣコンバータの回路図である。It is a circuit diagram of the DC-DC converter of one embodiment. 一実施形態のＤＣ－ＤＣコンバータに関し、第１直流電圧を第２直流電圧に変換するときのタイミングチャートである。FIG. 6 is a timing chart when converting a first DC voltage to a second DC voltage in the DC-DC converter of one embodiment. FIG. 一実施形態のＤＣ－ＤＣコンバータに関し、第２直流電圧を第１直流電圧に変換するときのタイミングチャートである。FIG. 7 is a timing chart when converting a second DC voltage to a first DC voltage in the DC-DC converter of one embodiment. FIG. 一実施形態のＤＣ－ＤＣコンバータにおいて、制御回路の動作モードを説明する説明図である。FIG. 6 is an explanatory view for explaining an operation mode of a control circuit in the DC-DC converter of one embodiment. 一実施形態のＤＣ－ＤＣコンバータに関し、第１動作モードによって第１直流電圧を第２直流電圧に変換するときのタイミングチャートである。FIG. 6 is a timing chart when converting a first DC voltage to a second DC voltage according to a first operation mode in the DC-DC converter of one embodiment. FIG. 一実施形態のＤＣ－ＤＣコンバータに関し、第１動作モードによって第２直流電圧を第１直流電圧に変換するときのタイミングチャートである。FIG. 6 is a timing chart when the second DC voltage is converted to the first DC voltage according to the first operation mode in the DC-DC converter of the embodiment. 一実施形態のＤＣ－ＤＣコンバータに関し、第２動作モードによって第１直流電圧を第２直流電圧に変換するときのタイミングチャートである。It is a timing chart when converting a 1st direct current voltage into a 2nd direct current voltage by the 2nd operation mode about a DC-DC converter of one embodiment. 一実施形態のＤＣ－ＤＣコンバータに関し、第２動作モードによって第２直流電圧を第１直流電圧に変換するときのタイミングチャートである。It is a timing chart when converting a 2nd direct current voltage into a 1st direct current voltage by the 2nd operation mode about a DC-DC converter of one embodiment.
　以下では、一実施形態のＤＣ－ＤＣコンバータ１０について、図１～図３を参照しながら説明する。 Hereinafter, a DC-DC converter 10 according to an embodiment will be described with reference to FIGS. 1 to 3.
　ＤＣ－ＤＣコンバータ１０は、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とを双方向に電圧変換を行うＤＣ－ＤＣコンバータである。 The DC-DC converter 10 is a DC-DC converter that performs voltage conversion between the first DC voltage Vd1 and the second DC voltage Vd2 in both directions.
　ＤＣ－ＤＣコンバータ１０は、スイッチング回路１と、インダクタＬ１と、コンデンサＣ１と、トランスＴ１と、スイッチング回路２と、制御回路３とを備えている。トランスＴ１は、第１巻線Ｎ１１と第２巻線Ｎ１２とを備えている。第１巻線Ｎ１１と第２巻線Ｎ１２とは、磁気的に結合されている。 The DC-DC converter 10 includes a switching circuit 1, an inductor L 1, a capacitor C 1, a transformer T 1, a switching circuit 2 and a control circuit 3. The transformer T1 includes a first winding N11 and a second winding N12. The first winding N11 and the second winding N12 are magnetically coupled.
　ＤＣ－ＤＣコンバータ１０では、スイッチング回路１が、第１スイッチング回路に相当する。また、ＤＣ－ＤＣコンバータ１０では、スイッチング回路２が、第２スイッチング回路に相当する。 In the DC-DC converter 10, the switching circuit 1 corresponds to a first switching circuit. Further, in the DC-DC converter 10, the switching circuit 2 corresponds to a second switching circuit.
　スイッチング回路１は、第１直流電圧Ｖｄ１と第１交流電圧Ｖａ１とを双方向に電圧変換を行うように構成されている。スイッチング回路１は、例えば、フルブリッジ回路である。 The switching circuit 1 is configured to perform voltage conversion between the first DC voltage Vd1 and the first AC voltage Va1 in both directions. The switching circuit 1 is, for example, a full bridge circuit.
　スイッチング回路１は、一対の接続端１ａ，１ｂと、一対の接続端１ｃ，１ｄと、４つのスイッチング素子Ｑ１～Ｑ４とを備えている。なお、一対の接続端１ａ，１ｂは、スイッチング回路１における第１直流電圧Ｖｄ１側の一対の接続端に相当する。また、一対の接続端１ｃ，１ｄは、スイッチング回路１における第１交流電圧Ｖａ１側の一対の接続端に相当する。また、４つのスイッチング素子Ｑ１～Ｑ４の各々は、第１スイッチング素子に相当する。 The switching circuit 1 includes a pair of connection ends 1a and 1b, a pair of connection ends 1c and 1d, and four switching elements Q1 to Q4. The pair of connection ends 1 a and 1 b correspond to a pair of connection ends of the switching circuit 1 on the first DC voltage Vd 1 side. The pair of connection ends 1 c and 1 d correspond to a pair of connection ends of the switching circuit 1 on the side of the first AC voltage Va 1. Further, each of the four switching elements Q1 to Q4 corresponds to a first switching element.
　一対の接続端１ａ，１ｂ間には、例えば、蓄電池１１が電気的に接続される。蓄電池１１としては、例えば、鉛蓄電池、リチウムイオン電池などが挙げられる。接続端１ａは、蓄電池１１のプラス端子と電気的に接続される。接続端１ｂは、蓄電池１１のマイナス端子と電気的に接続される。蓄電池１１の端子間電圧は、第１直流電圧Ｖｄ１である。 For example, the storage battery 11 is electrically connected between the pair of connection ends 1a and 1b. As the storage battery 11, a lead storage battery, a lithium ion battery, etc. are mentioned, for example. The connection end 1 a is electrically connected to the positive terminal of the storage battery 11. The connection end 1 b is electrically connected to the negative terminal of the storage battery 11. The inter-terminal voltage of the storage battery 11 is a first DC voltage Vd1.
　一対の接続端１ｃ，１ｄ間には、インダクタＬ１とコンデンサＣ１と第１巻線Ｎ１１との直列回路が電気的に接続されている。要するに、一対の接続端１ｃ，１ｄ間には、第１巻線Ｎ１１が電気的に接続されている。また、インダクタＬ１とコンデンサＣ１との直列回路４は、スイッチング回路１における一対の接続端１ｃ，１ｄ間において、第１巻線Ｎ１１と電気的に直列接続されている。直列回路４は、直列型の共振回路を構成している。 A series circuit of an inductor L1, a capacitor C1 and a first winding N11 is electrically connected between the pair of connection ends 1c and 1d. In short, the first winding N11 is electrically connected between the pair of connection ends 1c and 1d. The series circuit 4 of the inductor L1 and the capacitor C1 is electrically connected in series with the first winding N11 between the pair of connection ends 1c and 1d in the switching circuit 1. The series circuit 4 constitutes a series resonant circuit.
　４つのスイッチング素子Ｑ１～Ｑ４の各々は、例えば、ノーマリオフ型のｎチャネルＭＯＳＦＥＴである。図１中の４つのスイッチング素子Ｑ１～Ｑ４に付加されたダイオードは、寄生ダイオードである。 Each of the four switching elements Q1 to Q4 is, for example, a normally-off n-channel MOSFET. The diodes added to the four switching elements Q1 to Q4 in FIG. 1 are parasitic diodes.
　スイッチング素子Ｑ１のドレイン端子は、接続端１ａと電気的に接続されている。スイッチング素子Ｑ１のソース端子は、スイッチング素子Ｑ２のドレイン端子と電気的に接続されている。スイッチング素子Ｑ１のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q1 is electrically connected to the connection end 1a. The source terminal of the switching element Q1 is electrically connected to the drain terminal of the switching element Q2. The gate terminal of the switching element Q1 is electrically connected to the control circuit 3.
　スイッチング素子Ｑ２のドレイン端子は、接続端１ｃと電気的に接続されている。スイッチング素子Ｑ２のソース端子は、接続端１ｂと電気的に接続されている。スイッチング素子Ｑ２のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q2 is electrically connected to the connection end 1c. The source terminal of the switching element Q2 is electrically connected to the connection end 1b. The gate terminal of the switching element Q2 is electrically connected to the control circuit 3.
　スイッチング素子Ｑ３のドレイン端子は、スイッチング素子Ｑ１のドレイン端子と電気的に接続されている。スイッチング素子Ｑ３のソース端子は、スイッチング素子Ｑ４のドレイン端子と電気的に接続されている。スイッチング素子Ｑ３のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q3 is electrically connected to the drain terminal of the switching element Q1. The source terminal of the switching element Q3 is electrically connected to the drain terminal of the switching element Q4. The gate terminal of the switching element Q3 is electrically connected to the control circuit 3.
　スイッチング素子Ｑ４のドレイン端子は、接続端１ｄと電気的に接続されている。スイッチング素子Ｑ４のソース端子は、スイッチング素子Ｑ２のソース端子と電気的に接続されている。スイッチング素子Ｑ４のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q4 is electrically connected to the connection end 1d. The source terminal of the switching element Q4 is electrically connected to the source terminal of the switching element Q2. The gate terminal of the switching element Q4 is electrically connected to the control circuit 3.
　なお、スイッチング回路１は、フルブリッジ回路に限らず、例えば、ハーフブリッジ回路またはプッシュプル回路であってもよい。 The switching circuit 1 is not limited to the full bridge circuit, but may be, for example, a half bridge circuit or a push-pull circuit.
　スイッチング回路２は、スイッチング回路１と同様に、第２交流電圧Ｖａ２と第２直流電圧Ｖｄ２とを双方向に電圧変換を行うように構成されている。スイッチング回路２は、例えば、フルブリッジ回路である。 Similar to the switching circuit 1, the switching circuit 2 is configured to perform voltage conversion between the second AC voltage Va <b> 2 and the second DC voltage Vd <b> 2 in both directions. The switching circuit 2 is, for example, a full bridge circuit.
　スイッチング回路２は、一対の接続端２ａ，２ｂと、一対の接続端２ｃ，２ｄと、４つのスイッチング素子Ｑ５～Ｑ８とを備えている。なお、一対の接続端２ａ，２ｂは、スイッチング回路２における第２交流電圧Ｖａ２側の一対の接続端に相当する。また、一対の接続端２ｃ，２ｄは、スイッチング回路２における第２直流電圧Ｖｄ２側の一対の接続端に相当する。また、４つのスイッチング素子Ｑ５～Ｑ８の各々は、第２スイッチング素子に相当する。 The switching circuit 2 includes a pair of connection ends 2a and 2b, a pair of connection ends 2c and 2d, and four switching elements Q5 to Q8. The pair of connection ends 2 a and 2 b correspond to a pair of connection ends of the switching circuit 2 on the side of the second AC voltage Va 2. The pair of connection ends 2 c and 2 d correspond to a pair of connection ends of the switching circuit 2 on the second DC voltage Vd 2 side. Each of the four switching elements Q5 to Q8 corresponds to a second switching element.
　一対の接続端２ａ，２ｂ間には、第２巻線Ｎ１２が電気的に接続されている。 A second winding N12 is electrically connected between the pair of connection ends 2a and 2b.
　一対の接続端２ｃ，２ｄ間には、例えば、直流電圧源１２が電気的に接続される。直流電圧源１２は、例えば、電解コンデンサである。接続端２ｃは、電解コンデンサの高電位側の端子と電気的に接続される。接続端２ｄは、電解コンデンサの低電位側の端子と電気的に接続される。直流電圧源１２の端子間電圧は、第２直流電圧Ｖｄ２である。なお、直流電圧源１２は、電解コンデンサであるが、これに限定されない。 For example, a DC voltage source 12 is electrically connected between the pair of connection ends 2c and 2d. The DC voltage source 12 is, for example, an electrolytic capacitor. The connection end 2c is electrically connected to the terminal on the high potential side of the electrolytic capacitor. The connection end 2d is electrically connected to the low potential side terminal of the electrolytic capacitor. The inter-terminal voltage of the DC voltage source 12 is a second DC voltage Vd2. In addition, although the DC voltage source 12 is an electrolytic capacitor, it is not limited to this.
　４つのスイッチング素子Ｑ５～Ｑ８の各々は、例えば、ノーマリオフ型のｎチャネルＭＯＳＦＥＴである。図１中の４つのスイッチング素子Ｑ５～Ｑ８に付加されたダイオードは、寄生ダイオードである。 Each of the four switching elements Q5 to Q8 is, for example, a normally-off n-channel MOSFET. The diodes added to the four switching elements Q5 to Q8 in FIG. 1 are parasitic diodes.
　スイッチング素子Ｑ５のドレイン端子は、スイッチング素子Ｑ７のドレイン端子と電気的に接続されている。スイッチング素子Ｑ５のソース端子は、スイッチング素子Ｑ６のドレイン端子と電気的に接続されている。スイッチング素子Ｑ５のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q5 is electrically connected to the drain terminal of the switching element Q7. The source terminal of the switching element Q5 is electrically connected to the drain terminal of the switching element Q6. The gate terminal of the switching element Q5 is electrically connected to the control circuit 3.
　スイッチング素子Ｑ６のドレイン端子は、接続端２ａと電気的に接続されている。スイッチング素子Ｑ６のソース端子は、スイッチング素子Ｑ８のソース端子と電気的に接続されている。スイッチング素子Ｑ６のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q6 is electrically connected to the connection end 2a. The source terminal of the switching element Q6 is electrically connected to the source terminal of the switching element Q8. The gate terminal of the switching element Q6 is electrically connected to the control circuit 3.
　スイッチング素子Ｑ７のドレイン端子は、接続端２ｃと電気的に接続されている。スイッチング素子Ｑ７のソース端子は、スイッチング素子Ｑ８のドレイン端子と電気的に接続されている。スイッチング素子Ｑ７のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q7 is electrically connected to the connection end 2c. The source terminal of the switching element Q7 is electrically connected to the drain terminal of the switching element Q8. The gate terminal of the switching element Q7 is electrically connected to the control circuit 3.
　スイッチング素子Ｑ８のドレイン端子は、接続端２ｂと電気的に接続されている。スイッチング素子Ｑ８のソース端子は、接続端２ｄと電気的に接続されている。スイッチング素子Ｑ８のゲート端子は、制御回路３と電気的に接続されている。 The drain terminal of the switching element Q8 is electrically connected to the connection end 2b. The source terminal of the switching element Q8 is electrically connected to the connection end 2d. The gate terminal of the switching element Q8 is electrically connected to the control circuit 3.
　なお、スイッチング回路２は、フルブリッジ回路に限らず、例えば、ハーフブリッジ回路またはプッシュプル回路であってもよい。 The switching circuit 2 is not limited to the full bridge circuit, but may be, for example, a half bridge circuit or a push-pull circuit.
　制御回路３は、スイッチング回路１およびスイッチング回路２を制御するように構成されている。制御回路３は、例えば、プログラムが搭載されたマイクロコンピュータである。なお、制御回路３は、マイクロコンピュータに限らず、例えば、制御用ＩＣであってもよい。 The control circuit 3 is configured to control the switching circuit 1 and the switching circuit 2. The control circuit 3 is, for example, a microcomputer equipped with a program. The control circuit 3 is not limited to a microcomputer, and may be, for example, a control IC.
　制御回路３は、第１制御信号によりスイッチング回路１を制御するように構成されている。言い換えれば、制御回路３は、４つの第１制御信号によって、４つのスイッチング素子Ｑ１～Ｑ４を各別に制御するように構成されている。 The control circuit 3 is configured to control the switching circuit 1 by the first control signal. In other words, the control circuit 3 is configured to individually control the four switching elements Q1 to Q4 by the four first control signals.
　４つの第１制御信号は、それぞれ対応する４つのスイッチング素子Ｑ１～Ｑ４を制御する信号である。すなわち、制御回路３は、スイッチング回路１において４つのスイッチング素子Ｑ１～Ｑ４を各別に制御するように構成されている。４つの第１制御信号の各々は、例えば、ＰＷＭ信号である。 The four first control signals are signals for controlling the corresponding four switching elements Q1 to Q4, respectively. That is, the control circuit 3 is configured to control the four switching elements Q1 to Q4 separately in the switching circuit 1. Each of the four first control signals is, for example, a PWM signal.
　また、制御回路３は、第２制御信号によりスイッチング回路２を制御するように構成されている。言い換えれば、制御回路３は、４つの第２制御信号によって、４つのスイッチング素子Ｑ５～Ｑ８を各別に制御するように構成されている。 Further, the control circuit 3 is configured to control the switching circuit 2 by the second control signal. In other words, the control circuit 3 is configured to separately control the four switching elements Q5 to Q8 by the four second control signals.
　４つの第２制御信号は、それぞれ対応する４つのスイッチング素子Ｑ５～Ｑ８を制御する信号である。すなわち、制御回路３は、スイッチング回路２において４つのスイッチング素子Ｑ５～Ｑ８を各別に制御するように構成されている。４つの第２制御信号の各々は、例えば、ＰＷＭ信号である。 The four second control signals are signals for controlling the corresponding four switching elements Q5 to Q8. That is, the control circuit 3 is configured to separately control the four switching elements Q5 to Q8 in the switching circuit 2. Each of the four second control signals is, for example, a PWM signal.
　ＤＣ－ＤＣコンバータ１０では、４つの第１制御信号それぞれの周波数と、４つの第２制御信号それぞれの周波数とが、同じ周波数である。また、ＤＣ－ＤＣコンバータ１０では、４つの第１制御信号それぞれのデューティ比と、４つの第２制御信号それぞれのデューティ比とが、同じデューティ比である。 In the DC-DC converter 10, the frequencies of the four first control signals and the frequencies of the four second control signals are the same. Further, in the DC-DC converter 10, the duty ratio of each of the four first control signals and the duty ratio of each of the four second control signals are the same.
　また、制御回路３は、スイッチング回路１の動作とスイッチング回路２の動作とを同期させるように構成されている。言い換えれば、制御回路３は、４つのスイッチング素子Ｑ１～Ｑ４それぞれのスイッチング動作と、４つのスイッチング素子Ｑ５～Ｑ８それぞれのスイッチング動作とを同期させるように構成されている。例えば、制御回路３は、２つのスイッチング素子Ｑ１，Ｑ４と、２つのスイッチング素子Ｑ５，Ｑ８とを同時にオン状態にするように構成されている。 The control circuit 3 is also configured to synchronize the operation of the switching circuit 1 with the operation of the switching circuit 2. In other words, the control circuit 3 is configured to synchronize the switching operation of each of the four switching elements Q1 to Q4 with the switching operation of each of the four switching elements Q5 to Q8. For example, the control circuit 3 is configured to simultaneously turn on the two switching elements Q1 and Q4 and the two switching elements Q5 and Q8.
　ところで、制御回路３は、第１制御信号と第２制御信号との間の位相差Ｔｄ（図２，３参照）を可変とするように、第１制御信号の位相と第２制御信号の位相とを調節するように構成されている。なお、図２および図３中の横軸は、時間軸を表している。 The control circuit 3 changes the phase of the first control signal and the phase of the second control signal so as to make the phase difference Td (see FIGS. 2 and 3) between the first control signal and the second control signal variable. And are configured to adjust. The horizontal axes in FIGS. 2 and 3 represent time axes.
　一例を挙げて説明すると、制御回路３は、図２に示すように、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するとき、スイッチング素子Ｑ５を制御する第２制御信号の位相を、スイッチング素子Ｑ１を制御する第１制御信号の位相よりも遅らせる。また、制御回路３は、図２に示すように、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するとき、スイッチング素子Ｑ６を制御する第２制御信号の位相を、スイッチング素子Ｑ２を制御する第１制御信号の位相よりも遅らせる。なお、図２中のＱ１～Ｑ４は、スイッチング素子Ｑ１～Ｑ４にそれぞれ入力される第１制御信号の波形を表している。図２中のＱ５～Ｑ８は、スイッチング素子Ｑ５～Ｑ８にそれぞれ入力される第２制御信号の波形を表している。 For example, as shown in FIG. 2, when converting the first DC voltage Vd1 to the second DC voltage Vd2, the control circuit 3 switches the phase of the second control signal that controls the switching element Q5, as shown in FIG. The phase of the first control signal that controls the element Q1 is delayed. Further, as shown in FIG. 2, when converting the first DC voltage Vd1 to the second DC voltage Vd2, the control circuit 3 controls the phase of the second control signal that controls the switching element Q6 to control the switching element Q2. Delaying the phase of the first control signal. Note that Q1 to Q4 in FIG. 2 represent the waveforms of first control signals input to the switching elements Q1 to Q4, respectively. Q5 to Q8 in FIG. 2 represent the waveforms of second control signals input to the switching elements Q5 to Q8, respectively.
　また、他の例を挙げて説明すると、制御回路３は、図３に示すように、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するとき、スイッチング素子Ｑ１を制御する第１制御信号の位相を、スイッチング素子Ｑ５を制御する第２制御信号の位相よりも遅らせる。また、制御回路３は、図３に示すように、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するとき、スイッチング素子Ｑ２を制御する第１制御信号の位相を、スイッチング素子Ｑ６を制御する第２制御信号の位相よりも遅らせる。なお、図３中のＱ１～Ｑ４は、スイッチング素子Ｑ１～Ｑ４にそれぞれ入力される第１制御信号の波形を表している。図３中のＱ５～Ｑ８は、スイッチング素子Ｑ５～Ｑ８にそれぞれ入力される第２制御信号の波形を表している。スイッチング素子Ｑ４を制御する第１制御信号の位相と、スイッチング素子Ｑ８を制御する第２制御信号の位相との関係は、スイッチング素子Ｑ１を制御する第１制御信号の位相と、スイッチング素子Ｑ５を制御する第２制御信号の位相との関係と同じである。また、スイッチング素子Ｑ３を制御する第１制御信号の位相と、スイッチング素子Ｑ７を制御する第２制御信号の位相との関係は、スイッチング素子Ｑ２を制御する第１制御信号の位相と、スイッチング素子Ｑ６を制御する第２制御信号の位相との関係と同じである。 In addition, as described with reference to another example, as shown in FIG. 3, when the second DC voltage Vd2 is converted to the first DC voltage Vd1, the control circuit 3 controls the switching element Q1. The phase is delayed relative to the phase of the second control signal that controls the switching element Q5. Further, as shown in FIG. 3, when converting the second DC voltage Vd2 into the first DC voltage Vd1, the control circuit 3 controls the phase of the first control signal that controls the switching element Q2 to control the switching element Q6. Delaying the phase of the second control signal. Q1 to Q4 in FIG. 3 represent the waveforms of the first control signals input to the switching elements Q1 to Q4, respectively. Q5 to Q8 in FIG. 3 represent the waveforms of second control signals input to the switching elements Q5 to Q8, respectively. The relationship between the phase of the first control signal controlling the switching element Q4 and the phase of the second control signal controlling the switching element Q8 controls the phase of the first control signal controlling the switching element Q1 and the switching element Q5 And the phase of the second control signal. The relationship between the phase of the first control signal controlling the switching element Q3 and the phase of the second control signal controlling the switching element Q7 is the same as the phase of the first control signal controlling the switching element Q2, and the switching element Q6. And the phase of the second control signal that controls the
　以下では、ＤＣ－ＤＣコンバータ１０に関し、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するときの動作について、図２に基づいて説明する。なお、蓄電池１１は、予め充電されており、蓄電池１１が第１直流電圧Ｖｄ１を出力する場合について説明する。図２中のＶｒは、直列回路４で発生する共振電圧の波形を表している。図２中のＩｒは、直列回路４に流れる共振電流の波形を表している。図２中のＩＱ１～ＩＱ８は、スイッチング素子Ｑ１～Ｑ８に流れる電流の波形を表している。図２中のＩａ１は、スイッチング回路１から出力された電流の波形を表している。図２中のＩａ２は、スイッチング回路２に入力された電流の波形を表している。 In the following, regarding the DC-DC converter 10, an operation when converting the first DC voltage Vd1 into the second DC voltage Vd2 will be described based on FIG. In addition, the storage battery 11 is charged beforehand and the case where the storage battery 11 outputs 1st DC voltage Vd1 is demonstrated. Vr in FIG. 2 represents the waveform of the resonant voltage generated in the series circuit 4. Ir in FIG. 2 represents the waveform of the resonant current flowing in the series circuit 4. IQ1 to IQ8 in FIG. 2 represent the waveforms of currents flowing through the switching elements Q1 to Q8. Ia1 in FIG. 2 represents the waveform of the current output from the switching circuit 1. Ia2 in FIG. 2 represents the waveform of the current input to the switching circuit 2.
　制御回路３は、２つのスイッチング素子Ｑ１，Ｑ４と、２つのスイッチング素子Ｑ２，Ｑ３とが交互にオン状態となるようにスイッチング回路１を制御する。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路１が、第１直流電圧Ｖｄ１を第１交流電圧Ｖａ１に変換するインバータ回路として動作する。 The control circuit 3 controls the switching circuit 1 so that the two switching elements Q1 and Q4 and the two switching elements Q2 and Q3 are alternately turned on. Thereby, in the DC-DC converter 10, the switching circuit 1 operates as an inverter circuit that converts the first DC voltage Vd1 into the first AC voltage Va1.
　ＤＣ－ＤＣコンバータ１０では、スイッチング回路１からの第１交流電圧Ｖａ１が直列回路４によって共振され、直列回路４により共振された電圧がトランスＴ１の第１巻線Ｎ１１に印加される。これにより、ＤＣ－ＤＣコンバータ１０では、トランスＴ１の巻数比に応じてトランスＴ１の第２巻線Ｎ１２に第１誘起電圧（第２交流電圧Ｖａ２）が発生し、第２交流電圧Ｖａ２をスイッチング回路２に入力することが可能となる。 In the DC-DC converter 10, the first alternating voltage Va1 from the switching circuit 1 is resonated by the series circuit 4, and the voltage resonated by the series circuit 4 is applied to the first winding N11 of the transformer T1. Thereby, in the DC-DC converter 10, the first induction voltage (second alternating voltage Va2) is generated in the second winding N12 of the transformer T1 according to the turns ratio of the transformer T1, and the second alternating voltage Va2 is switched to the switching circuit It becomes possible to input to 2.
　制御回路３は、４つの第２制御信号それぞれの位相を、４つの第１制御信号それぞれの位相よりも遅らせる。また、制御回路３は、２つのスイッチング素子Ｑ５，Ｑ８と、２つのスイッチング素子Ｑ６，Ｑ７とが交互にオン状態となるようにスイッチング回路２を制御する。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路２に入力された第２交流電圧Ｖａ２を第２直流電圧Ｖｄ２に変換することが可能となる。 The control circuit 3 delays the phase of each of the four second control signals more than the phase of each of the four first control signals. Further, the control circuit 3 controls the switching circuit 2 so that the two switching elements Q5 and Q8 and the two switching elements Q6 and Q7 are alternately turned on. Thus, in the DC-DC converter 10, it is possible to convert the second AC voltage Va2 input to the switching circuit 2 into a second DC voltage Vd2.
　したがって、ＤＣ－ＤＣコンバータ１０では、スイッチング回路１により第１直流電圧Ｖｄ１を第１交流電圧Ｖａ１に変換した後、スイッチング回路２により第２交流電圧Ｖａ２を第２直流電圧Ｖｄ２に変換することが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換することが可能となり、第２直流電圧Ｖｄ２を、直流電圧源１２である電解コンデンサに印加することが可能となる。要するに、ＤＣ－ＤＣコンバータ１０では、蓄電池１１を放電することが可能となる。 Therefore, in DC-DC converter 10, after first DC voltage Vd1 is converted to first AC voltage Va1 by switching circuit 1, second AC voltage Va2 can be converted to second DC voltage Vd2 by switching circuit 2. It becomes. As a result, in the DC-DC converter 10, the first DC voltage Vd1 can be converted to the second DC voltage Vd2, and the second DC voltage Vd2 can be applied to the electrolytic capacitor which is the DC voltage source 12. It becomes. In short, in the DC-DC converter 10, the storage battery 11 can be discharged.
　また、以下では、ＤＣ－ＤＣコンバータ１０に関し、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するときの動作について、図３に基づいて説明する。なお、直流電圧源１２である電解コンデンサに、電荷が予め蓄積されており、直流電圧源１２が第２直流電圧Ｖｄ２を出力する場合について説明する。図３中のＶｒは、直列回路４で発生する共振電圧の波形を表している。図３中のＩｒは、直列回路４に流れる共振電流の波形を表している。図３中のＩＱ１～ＩＱ８は、スイッチング素子Ｑ１～Ｑ８に流れる電流の波形を表している。図３中のＩａ１は、スイッチング回路１に入力された電流の波形を表している。図３中のＩａ２は、スイッチング回路２から出力された電流の波形を表している。 Further, in the following, regarding the DC-DC converter 10, an operation when converting the second DC voltage Vd2 into the first DC voltage Vd1 will be described based on FIG. A case where electric charges are stored in advance in the electrolytic capacitor which is the DC voltage source 12 and the DC voltage source 12 outputs the second DC voltage Vd2 will be described. Vr in FIG. 3 represents the waveform of the resonant voltage generated in the series circuit 4. Ir in FIG. 3 represents the waveform of the resonant current flowing in the series circuit 4. IQ1 to IQ8 in FIG. 3 represent the waveforms of currents flowing through the switching elements Q1 to Q8. Ia1 in FIG. 3 represents the waveform of the current input to the switching circuit 1. Ia2 in FIG. 3 represents the waveform of the current output from the switching circuit 2.
　制御回路３は、２つのスイッチング素子Ｑ５，Ｑ８と、２つのスイッチング素子Ｑ６，Ｑ７とが交互にオン状態となるようにスイッチング回路２を制御する。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路２が、第２直流電圧Ｖｄ２を第２交流電圧Ｖａ２に変換するインバータ回路として動作する。よって、ＤＣ－ＤＣコンバータ１０では、スイッチング回路２により変換された第２交流電圧Ｖａ２をトランスＴ１の第２巻線Ｎ１２に印加することが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、トランスＴ１の第１巻線Ｎ１１に第２誘起電圧が発生する。 The control circuit 3 controls the switching circuit 2 so that the two switching elements Q5 and Q8 and the two switching elements Q6 and Q7 are alternately turned on. Thus, in the DC-DC converter 10, the switching circuit 2 operates as an inverter circuit that converts the second DC voltage Vd2 into the second AC voltage Va2. Therefore, in the DC-DC converter 10, it is possible to apply the second AC voltage Va2 converted by the switching circuit 2 to the second winding N12 of the transformer T1. As a result, in the DC-DC converter 10, a second induced voltage is generated in the first winding N11 of the transformer T1.
　ＤＣ－ＤＣコンバータ１０では、トランスＴ１の第１巻線Ｎ１１で発生した第２誘起電圧が直列回路４によって共振され、直列回路４により共振された電圧（第１交流電圧Ｖａ１）をスイッチング回路１に入力することが可能となる。 In the DC-DC converter 10, the second induced voltage generated in the first winding N11 of the transformer T1 is resonated by the series circuit 4, and the voltage (first alternating voltage Va1) resonated by the series circuit 4 is used as the switching circuit 1. It becomes possible to input.
　制御回路３は、４つの第１制御信号それぞれの位相を、４つの第２制御信号それぞれの位相よりも遅らせる。また、制御回路３は、２つのスイッチング素子Ｑ１，Ｑ４と、２つのスイッチング素子Ｑ２，Ｑ３とが交互にオン状態となるようにスイッチング回路１を制御する。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路１に入力された第１交流電圧Ｖａを第１直流電圧Ｖｄ１に変換することが可能となる。 The control circuit 3 delays the phase of each of the four first control signals more than the phase of each of the four second control signals. Further, the control circuit 3 controls the switching circuit 1 so that the two switching elements Q1 and Q4 and the two switching elements Q2 and Q3 are alternately turned on. Thereby, in the DC-DC converter 10, it becomes possible to convert the first AC voltage Va input to the switching circuit 1 into the first DC voltage Vd1.
　したがって、ＤＣ－ＤＣコンバータ１０では、スイッチング回路２により第２直流電圧Ｖｄ２を第２交流電圧Ｖａ２に変換した後、スイッチング回路１により第１交流電圧Ｖａ１を第１直流電圧Ｖｄ１に変換することが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換することが可能となり、第１直流電圧Ｖｄ１を、蓄電池１１に印加することが可能となる。要するに、ＤＣ－ＤＣコンバータ１０では、蓄電池１１を充電することが可能となる。 Therefore, in the DC-DC converter 10, after the second DC voltage Vd2 is converted to the second AC voltage Va2 by the switching circuit 2, the first AC voltage Va1 can be converted to the first DC voltage Vd1 by the switching circuit 1. It becomes. As a result, in the DC-DC converter 10, the second DC voltage Vd2 can be converted to the first DC voltage Vd1, and the first DC voltage Vd1 can be applied to the storage battery 11. In short, in the DC-DC converter 10, the storage battery 11 can be charged.
　以上のとおり、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するとき、制御回路３が、第２制御信号の位相を第１制御信号の位相よりも遅らせる。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路１から出力された電流Ｉａ１を、スイッチング回路２に入力された電流Ｉａ２よりも大きくすることが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換することが可能となる。 As described above, in the DC-DC converter 10, when converting the first DC voltage Vd1 into the second DC voltage Vd2, the control circuit 3 delays the phase of the second control signal more than the phase of the first control signal. Thereby, in the DC-DC converter 10, the current Ia1 output from the switching circuit 1 can be made larger than the current Ia2 input to the switching circuit 2. Therefore, in the DC-DC converter 10, it is possible to convert the first DC voltage Vd1 into the second DC voltage Vd2.
　また、ＤＣ－ＤＣコンバータ１０では、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するとき、制御回路３が、第１制御信号の位相を第２制御信号の位相よりも遅らせる。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路２から出力された電流Ｉａ２を、スイッチング回路１に入力された電流Ｉａ１よりも大きくすることが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換することが可能となる。 Further, in the DC-DC converter 10, when converting the second DC voltage Vd2 into the first DC voltage Vd1, the control circuit 3 delays the phase of the first control signal more than the phase of the second control signal. Thereby, in the DC-DC converter 10, the current Ia2 output from the switching circuit 2 can be made larger than the current Ia1 input to the switching circuit 1. Therefore, in the DC-DC converter 10, it is possible to convert the second DC voltage Vd2 into the first DC voltage Vd1.
　よって、ＤＣ－ＤＣコンバータ１０では、従来例１のＤＣ－ＤＣコンバータにおける昇圧回路もしくは従来例２のＤＣ－ＤＣコンバータにおけるチョッパ回路を用いることなく、簡単な構成で双方向に電圧変換を行うことが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を向上させることが可能となる。また、ＤＣ－ＤＣコンバータ１０では、従来例２のＤＣ－ＤＣコンバータにおけるチョッパ回路が不要となるので、従来例２のＤＣ－ＤＣコンバータに比べて、双方向の電圧変換において変換効率を向上させることが可能となる。すなわち、ＤＣ－ＤＣコンバータ１０では、双方向に電圧変換を行うことが可能で、かつ、双方向の電圧変換において変換効率を向上させることが可能となる。 Therefore, in the DC-DC converter 10, bidirectional voltage conversion can be performed with a simple configuration without using the booster circuit in the DC-DC converter of Conventional Example 1 or the chopper circuit in the DC-DC converter of Conventional Example 2. It becomes possible. As a result, in the DC-DC converter 10, the conversion efficiency can be improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Further, in the DC-DC converter 10, since the chopper circuit in the DC-DC converter of the prior art 2 becomes unnecessary, the conversion efficiency is improved in bidirectional voltage conversion as compared with the DC-DC converter of the prior art 2. Is possible. That is, in the DC-DC converter 10, voltage conversion can be performed bidirectionally, and conversion efficiency can be improved in bidirectional voltage conversion.
　また、ＤＣ－ＤＣコンバータ１０では、制御回路３が、第１制御信号と第２制御信号との間の位相差を可変とするように、第１制御信号の位相と第２制御信号の位相とを調節するように構成されている。これにより、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２との大小関係を適宜変更することが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、トランスＴ１の巻数比と、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とを双方向に電圧変換を行う電圧変換比との大小関係に関わらず、双方向に電圧変換を行うことが可能となる。 In the DC-DC converter 10, the phase of the first control signal and the phase of the second control signal are controlled so that the control circuit 3 changes the phase difference between the first control signal and the second control signal. Is configured to adjust. As a result, in the DC-DC converter 10, the magnitude relationship between the first DC voltage Vd1 and the second DC voltage Vd2 can be appropriately changed. Therefore, in the DC-DC converter 10, regardless of the magnitude relationship between the turns ratio of the transformer T1 and the voltage conversion ratio for performing voltage conversion of the first DC voltage Vd1 and the second DC voltage Vd2 in both directions, It becomes possible to perform voltage conversion.
　ただし、ＤＣ－ＤＣコンバータ１０では、上記電圧変換比によって、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するときの変換効率と、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するときの変換効率との差が生じる可能性がある。なお、以下では、説明の便宜上、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するときの変換効率を「第１変換効率」と称し、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するときの変換効率を「第２変換効率」と称する。 However, in the DC-DC converter 10, the conversion efficiency when converting the first DC voltage Vd1 to the second DC voltage Vd2 and the second DC voltage Vd2 to the first DC voltage Vd1 according to the voltage conversion ratio There may be a difference with the conversion efficiency of In the following, for convenience of explanation, the conversion efficiency when converting the first DC voltage Vd1 to the second DC voltage Vd2 is referred to as "first conversion efficiency" and the second DC voltage Vd2 is converted to the first DC voltage Vd1. The conversion efficiency at the time is referred to as "second conversion efficiency".
　本願発明者は、ＤＣ－ＤＣコンバータ１０において、トランスＴ１の巻数比と上記電圧変換比とを同じ比率にすれば、第１変換効率と第２変換効率との差を抑制することが可能になるという知見を得た。しかしながら、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが一定の範囲内でそれぞれ変動するため、トランスＴ１の巻数比と上記電圧変換比とを同じ比率にすることが難しい。 In the DC-DC converter 10, the inventor of the present application can suppress the difference between the first conversion efficiency and the second conversion efficiency by setting the turns ratio of the transformer T1 to the same ratio as the voltage conversion ratio. I got the knowledge that. However, in the DC-DC converter 10, since the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 respectively fluctuate within a predetermined range, the turns ratio of the transformer T1 and the voltage conversion ratio It is difficult to make the same ratio.
　そこで、トランスＴ１の巻数比は、第１直流電圧Ｖｄ１の最大値を第２直流電圧Ｖｄ２の最小値で除算した値よりも小さく、かつ、第１直流電圧Ｖｄ１の最小値を第２直流電圧Ｖｄ２の最大値で除算した値よりも大きいことが好ましい。トランスＴ１の巻数比は、第１巻線Ｎ１１の巻線数を第２巻線Ｎ１２の巻線数で除算した値で表される。これにより、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが一定の範囲内でそれぞれ変動する場合であっても、第１変換効率と第２変換効率との差を抑制することが可能となる。 Therefore, the turns ratio of the transformer T1 is smaller than a value obtained by dividing the maximum value of the first DC voltage Vd1 by the minimum value of the second DC voltage Vd2, and the minimum value of the first DC voltage Vd1 is equal to the second DC voltage Vd2. Preferably, it is greater than the value divided by the maximum value of. The turns ratio of the transformer T1 is represented by a value obtained by dividing the number of turns of the first winding N11 by the number of turns of the second winding N12. Thereby, in the DC-DC converter 10, even if the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 respectively fluctuate within a predetermined range, the first conversion efficiency and the second conversion efficiency It becomes possible to suppress the difference with conversion efficiency.
　また、トランスＴ１の巻数比は、直流電圧源１２の端子間電圧を、蓄電池１１における充電時の端子間電圧と蓄電池１１における放電時の端子間電圧との平均値で除算した値を基準値とする所定範囲内の値であってもよい。これにより、ＤＣ－ＤＣコンバータ１０では、トランスＴ１の巻数比によっても、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とを双方向に電圧変換を行うことが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、第１変換効率と、第２変換効率との差を抑制することが可能となる。 Further, the turns ratio of the transformer T1 is obtained by dividing a voltage between terminals of the DC voltage source 12 by an average value of a voltage between terminals at charging in the storage battery 11 and a voltage at terminals in discharging the storage battery 11 as a reference value. It may be a value within a predetermined range. As a result, in the DC-DC converter 10, the voltage conversion can be performed bidirectionally between the first DC voltage Vd1 and the second DC voltage Vd2 also by the turn ratio of the transformer T1. As a result, in the DC-DC converter 10, it is possible to suppress the difference between the first conversion efficiency and the second conversion efficiency.
　第１制御信号および第２制御信号それぞれの周波数は、直列回路４の共振周波数以上であることが好ましい。例えば、第１制御信号および第２制御信号それぞれの周波数は、第１制御信号および第２制御信号それぞれの周波数をｆ、直列回路４の共振周波数をｆｒとするとき、ｆ≧ｆｒを満たす。 The frequency of each of the first control signal and the second control signal is preferably equal to or higher than the resonant frequency of the series circuit 4. For example, when the frequency of each of the first control signal and the second control signal is f and the resonance frequency of the series circuit 4 is fr, the frequencies of the first control signal and the second control signal satisfy fffr.
　これにより、ＤＣ－ＤＣコンバータ１０では、４つのスイッチング素子Ｑ１～Ｑ４および４つのスイッチング素子Ｑ５～Ｑ８の各々が、ハードスイッチング動作するのを抑制することが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、スイッチング損失を抑制することが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より向上させることが可能となる。 As a result, in the DC-DC converter 10, it is possible to suppress the hard switching operation of each of the four switching elements Q1 to Q4 and the four switching elements Q5 to Q8. Therefore, in the DC-DC converter 10, it is possible to suppress the switching loss. As a result, in the DC-DC converter 10, the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
　制御回路３は、第１制御信号と第２制御信号との間の位相差Ｔｄが増加するとき、第１制御信号および第２制御信号それぞれの周波数を増加させることが好ましい。ＤＣ－ＤＣコンバータ１０では、第１制御信号と第２制御信号との間の位相差Ｔｄが増加すると、直列回路４に印加される電圧の絶対値が増加する。その結果、ＤＣ－ＤＣコンバータ１０では、第１制御信号と第２制御信号との間の位相差Ｔｄがゼロの場合に比べて、インダクタＬ１とコンデンサＣ１との間におけるエネルギー移動が加速され、直列回路４の共振周波数が見かけ上、上昇する。 The control circuit 3 preferably increases the frequency of each of the first control signal and the second control signal when the phase difference Td between the first control signal and the second control signal increases. In the DC-DC converter 10, when the phase difference Td between the first control signal and the second control signal increases, the absolute value of the voltage applied to the series circuit 4 increases. As a result, in the DC-DC converter 10, energy transfer between the inductor L1 and the capacitor C1 is accelerated compared with the case where the phase difference Td between the first control signal and the second control signal is zero, and thus series The resonant frequency of the circuit 4 apparently increases.
　そこで、ＤＣ－ＤＣコンバータ１０では、第１制御信号と第２制御信号との間の位相差Ｔｄが増加するときに、第１制御信号および第２制御信号それぞれの周波数を増加させる。これにより、ＤＣ－ＤＣコンバータ１０では、４つのスイッチング素子Ｑ１～Ｑ４および４つのスイッチング素子Ｑ５～Ｑ８の各々が、ハードスイッチング動作するのを抑制することが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、スイッチング損失を抑制することが可能となる。その結果、ＤＣ－ＤＣコンバータ１０では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より向上させることが可能となる。 Therefore, in the DC-DC converter 10, when the phase difference Td between the first control signal and the second control signal increases, the frequencies of the first control signal and the second control signal are increased. As a result, in the DC-DC converter 10, it is possible to suppress the hard switching operation of each of the four switching elements Q1 to Q4 and the four switching elements Q5 to Q8. Therefore, in the DC-DC converter 10, it is possible to suppress the switching loss. As a result, in the DC-DC converter 10, the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
　ＤＣ－ＤＣコンバータ１０は、図１に示すように、直列回路４に流れる共振電流Ｉｒの位相を検出する検出回路５を、更に備えている。 As shown in FIG. 1, the DC-DC converter 10 further includes a detection circuit 5 that detects the phase of the resonant current Ir flowing in the series circuit 4.
　検出回路５は、第１検出部６と、第２検出部７とを備えている。 The detection circuit 5 includes a first detection unit 6 and a second detection unit 7.
　制御回路３は、直列回路４に流れる共振電流Ｉｒの位相に応じて、一対の接続端１ｃ，１ｄ間の電圧もしくは一対の接続端２ａ，２ｂ間の電圧の位相と共振電流Ｉｒの位相との位相差が小さくなるように、スイッチング回路１およびスイッチング回路２のスイッチング周波数を制御する。直列回路４に流れる共振電流Ｉｒの位相は、第１検出部６もしくは第２検出部７によって検出される。 According to the phase of the resonant current Ir flowing through the series circuit 4, the control circuit 3 determines the voltage phase between the pair of connection ends 1c and 1d or the voltage phase between the pair of connection ends 2a and 2b and the phase of the resonant current Ir. The switching frequencies of the switching circuit 1 and the switching circuit 2 are controlled so that the phase difference is reduced. The phase of the resonant current Ir flowing in the series circuit 4 is detected by the first detection unit 6 or the second detection unit 7.
　具体的に説明すると、制御回路３は、共振電流Ｉｒの位相が一対の接続端１ｃ，１ｄ間の電圧もしくは一対の接続端２ａ，２ｂ間の電圧の位相に対して進相であるとき、スイッチング回路１およびスイッチング回路２のスイッチング周波数を増加させる。一方、制御回路３は、共振電流Ｉｒの位相が一対の接続端１ｃ，１ｄ間の電圧もしくは一対の接続端２ａ，２ｂ間の電圧の位相に対して遅相であるとき、スイッチング回路１およびスイッチング回路２のスイッチング周波数を減少させる。スイッチング回路１およびスイッチング回路２のスイッチング周波数は、同じ周波数である。 Specifically, the control circuit 3 performs switching when the phase of the resonance current Ir is in phase advance with respect to the voltage between the pair of connection ends 1c and 1d or the voltage between the pair of connection ends 2a and 2b. The switching frequency of the circuit 1 and the switching circuit 2 is increased. On the other hand, when the phase of the resonance current Ir is lagging with respect to the phase of the voltage between the pair of connection ends 1c and 1d or the voltage between the pair of connection ends 2a and 2b, the control circuit 3 performs switching circuit 1 and switching The switching frequency of circuit 2 is reduced. The switching frequencies of switching circuit 1 and switching circuit 2 are the same frequency.
　これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路１もしくはスイッチング回路２のスイッチング損失を最小化することが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より向上させることが可能となる。 Thereby, in the DC-DC converter 10, it is possible to minimize the switching loss of the switching circuit 1 or the switching circuit 2. Therefore, in the DC-DC converter 10, the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
　共振電流Ｉｒとの位相差の対象となる一対の接続端間の電圧の位相は、電力を供給する側として作用するスイッチング回路における一対の接続端間の電圧の位相であることが望ましい。例えば、上記対象となる一対の接続端間の電圧の位相は、スイッチング回路１からスイッチング回路２へ電力変換が行われるとき、一対の接続端１ｃ，１ｄ間の電圧の位相であることが望ましい。また、上記対象となる一対の接続端間の電圧の位相は、スイッチング回路２からスイッチング回路１へ電力変換が行われるとき、一対の接続端２ａ，２ｂ間の電圧の位相であることが望ましい。スイッチング周波数は、例えば、スイッチング回路１における４つのスイッチング素子Ｑ１～Ｑ４をスイッチング動作させるための周波数を意味する。 It is desirable that the phase of the voltage between the pair of connection ends to be subjected to the phase difference with the resonance current Ir be the phase of the voltage between the pair of connection ends in the switching circuit acting as the power supply side. For example, when the power conversion is performed from the switching circuit 1 to the switching circuit 2, it is preferable that the phase of the voltage between the pair of connection ends to be the target be the phase of the voltage between the pair of connection ends 1c and 1d. Further, it is desirable that the phase of the voltage between the pair of connection ends to be a target be the phase of the voltage between the pair of connection ends 2a and 2b when power conversion is performed from the switching circuit 2 to the switching circuit 1. The switching frequency means, for example, a frequency for switching the four switching elements Q1 to Q4 in the switching circuit 1.
　検出回路５は、第１検出部６と第２検出部７との両方を備えているが、第１検出部６と第２検出部７とのいずれか一方だけを備えていてもよい。また、ＤＣ－ＤＣコンバータ１０は、検出回路５を備えているが、検出回路５を備えていなくてもよい。 Although the detection circuit 5 includes both the first detection unit 6 and the second detection unit 7, the detection circuit 5 may include only one of the first detection unit 6 and the second detection unit 7. In addition, although the DC-DC converter 10 includes the detection circuit 5, the detection circuit 5 may not be included.
　検出回路５は、スイッチング回路１に流れる検出電流（以下、「第１検出電流」）とスイッチング回路２に流れる検出電流（以下、「第２検出電流」）とを検出するように構成されていることが好ましい。具体的に説明すると、第１検出部６は、スイッチング回路１に流れる第１検出電流を検出するように構成されていることが好ましい。第２検出部７は、スイッチング回路２に流れる第２検出電流を検出するように構成されていることが好ましい。 The detection circuit 5 is configured to detect a detection current flowing through the switching circuit 1 (hereinafter, “first detection current”) and a detection current flowing through the switching circuit 2 (hereinafter, “second detection current”). Is preferred. Specifically, preferably, the first detection unit 6 is configured to detect the first detection current flowing to the switching circuit 1. The second detection unit 7 is preferably configured to detect a second detection current flowing to the switching circuit 2.
　制御回路３は、検出回路５により検出された第１検出電流もしくは第２検出電流と、操作部により予め設定された設定電流との差が小さくなるように、第１制御信号と第２制御信号との間の位相差Ｔｄを制御するように構成されていることが好ましい。 The control circuit 3 sets the first control signal and the second control signal such that the difference between the first detection current or the second detection current detected by the detection circuit 5 and the set current preset by the operation unit becomes small. Preferably, it is configured to control the phase difference Td between them.
　具体的に説明すると、制御回路３は、検出回路５により検出された第１検出電流もしくは第２検出電流の絶対値が設定電流の絶対値よりも大きいとき、位相差Ｔｄの絶対値を減少させる。一方、制御回路３は、検出回路５により検出された第１検出電流もしくは第２検出電流の絶対値が設定電流の絶対値よりも小さいとき、位相差Ｔｄの絶対値を増加させる。これにより、ＤＣ－ＤＣコンバータ１０では、スイッチング回路１もしくはスイッチング回路２の設定電流に応じた最小損失動作点を選択することが可能となる。よって、ＤＣ－ＤＣコンバータ１０では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より一層向上させることが可能となる。 Specifically, the control circuit 3 decreases the absolute value of the phase difference Td when the absolute value of the first detection current or the second detection current detected by the detection circuit 5 is larger than the absolute value of the set current. . On the other hand, when the absolute value of the first detection current or the second detection current detected by the detection circuit 5 is smaller than the absolute value of the set current, the control circuit 3 increases the absolute value of the phase difference Td. Thus, in the DC-DC converter 10, it is possible to select the minimum loss operating point according to the set current of the switching circuit 1 or the switching circuit 2. Therefore, in the DC-DC converter 10, the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
　この場合、設定電流は、制御回路３である上記マイクロコンピュータの記憶部３ａに記憶されている。制御回路３は、記憶部３ａに記憶された設定電流と、検出回路５により検出された第１検出電流もしくは第２検出電流との比較演算を行い、この演算結果に基づいて第１制御信号および第２制御信号を生成するように構成されている。 In this case, the set current is stored in the storage unit 3 a of the microcomputer, which is the control circuit 3. The control circuit 3 compares the set current stored in the storage unit 3a with the first detection current or the second detection current detected by the detection circuit 5, and based on the calculation result, the first control signal and A second control signal is configured to be generated.
　ところで、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが許容範囲外まで変動する場合がある。許容範囲は、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とについて変動することが許容されている範囲である。つまり、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２との電圧比がトランスＴ１の巻数比と乖離する場合があり、動作が不安定になる可能性がある。 By the way, in the DC-DC converter 10, the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 may fluctuate outside the allowable range. The allowable range is a range in which the first DC voltage Vd1 and the second DC voltage Vd2 are allowed to fluctuate. That is, in the DC-DC converter 10, the voltage ratio between the first DC voltage Vd1 and the second DC voltage Vd2 may deviate from the turns ratio of the transformer T1, and the operation may become unstable.
　ＤＣ－ＤＣコンバータ１０では、検出回路５が、第１直流電圧Ｖｄ１および第２直流電圧Ｖｄ２を検出するように構成されていることが好ましい。検出回路５は、第３検出部８と、第４検出部９とを備えている。第３検出部８は、第１直流電圧Ｖｄ１を検出するように構成されている。第４検出部９は、第２直流電圧Ｖｄ２を検出するように構成されている。第３検出部８および第４検出部９は、制御回路３と電気的に接続されている。 In the DC-DC converter 10, the detection circuit 5 is preferably configured to detect the first DC voltage Vd1 and the second DC voltage Vd2. The detection circuit 5 includes a third detection unit 8 and a fourth detection unit 9. The third detection unit 8 is configured to detect the first DC voltage Vd1. The fourth detection unit 9 is configured to detect the second DC voltage Vd2. The third detection unit 8 and the fourth detection unit 9 are electrically connected to the control circuit 3.
　制御回路３は、検出回路５により検出された第１直流電圧Ｖｄ１および第２直流電圧Ｖｄ２に基づいて、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２との電圧比を算出するように構成されていることが好ましい。 The control circuit 3 is configured to calculate a voltage ratio between the first DC voltage Vd1 and the second DC voltage Vd2 based on the first DC voltage Vd1 and the second DC voltage Vd2 detected by the detection circuit 5. Is preferred.
　制御回路３は、図４に示すように、上述した制御（通常の制御）とは異なる、特定の制御を行う特定動作モードとして、第１動作モードと、第２動作モードとを有している。なお、通常の制御とは、制御回路３が、第１制御信号と第２制御信号との一方の位相を、第１制御信号と第２制御信号との他方の位相よりも遅らせるように、第１スイッチング回路１および第２スイッチング回路２を制御することを意味する（図４中のＡ１領域）。以下では、説明の便宜上、通常の制御を行う動作モードを、「通常の動作モード」と称する。 As shown in FIG. 4, the control circuit 3 has a first operation mode and a second operation mode as specific operation modes for performing specific control different from the above-described control (normal control). . In the normal control, the control circuit 3 delays the phase of one of the first control signal and the second control signal more than the other phase of the first control signal and the second control signal. 1 means controlling the switching circuit 1 and the second switching circuit 2 (area A1 in FIG. 4). Hereinafter, for convenience of explanation, an operation mode for performing normal control is referred to as a "normal operation mode".
　第１動作モードでは、制御回路３が、後述の規定状態となるように、第１スイッチング回路１および第２スイッチング回路２を制御する。規定状態とは、第１制御信号と第２制御信号との一方の位相を、第１制御信号と第２制御信号との他方の位相よりも遅らせ、かつ、上記他方がオン状態のときに上記一方がオフ状態である（図５および図６参照）。なお、図５は、ＤＣ－ＤＣコンバータ１０に関し、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するときのタイミングチャートを表している。また、図６は、ＤＣ－ＤＣコンバータ１０に関し、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するときのタイミングチャートを表している。図５および図６中の横軸は、時間軸を表している。 In the first operation mode, the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 so as to be in a prescribed state described later. In the prescribed state, one of the phases of the first control signal and the second control signal is delayed relative to the other phase of the first control signal and the second control signal, and the other is in the on state. One is in the off state (see FIGS. 5 and 6). FIG. 5 shows a timing chart when the first DC voltage Vd1 is converted to the second DC voltage Vd2 in the DC-DC converter 10. Further, FIG. 6 shows a timing chart when the second DC voltage Vd2 is converted into the first DC voltage Vd1 in the DC-DC converter 10. The horizontal axes in FIGS. 5 and 6 represent time axes.
　図５に基づいて説明すると、第１動作モードでは、制御回路３が、第２制御信号の位相を第１制御信号の位相よりも遅らせ、かつ、第１制御信号がオン状態のときに第２制御信号がオフ状態となるように、スイッチング回路１およびスイッチング回路２を制御する。 Referring to FIG. 5, in the first operation mode, the control circuit 3 delays the phase of the second control signal relative to the phase of the first control signal, and the second control signal is in the on state. The switching circuit 1 and the switching circuit 2 are controlled so that the control signal is turned off.
　第２動作モードでは、制御回路３が、上記一方の位相を上記他方の位相よりも遅らせ、かつ、上記他方のデューティ比が上記一方のデューティ比よりも小さくなるように、第１スイッチング回路１および第２スイッチング回路２を制御する（図７および図８参照）。なお、図７は、ＤＣ－ＤＣコンバータ１０に関し、第１直流電圧Ｖｄ１を第２直流電圧Ｖｄ２に変換するときのタイミングチャートを表している。また、図８は、ＤＣ－ＤＣコンバータ１０に関し、第２直流電圧Ｖｄ２を第１直流電圧Ｖｄ１に変換するときのタイミングチャートを表している。図７および図８中の横軸は、時間軸を表している。 In the second operation mode, the first switching circuit 1 and the first switching circuit 1 are configured such that the control circuit 3 delays the one phase more than the other phase, and the other duty ratio is smaller than the one duty ratio. The second switching circuit 2 is controlled (see FIGS. 7 and 8). FIG. 7 is a timing chart when the first DC voltage Vd1 is converted to the second DC voltage Vd2 in the DC-DC converter 10. Further, FIG. 8 shows a timing chart when the second DC voltage Vd2 is converted into the first DC voltage Vd1 in the DC-DC converter 10. The horizontal axes in FIGS. 7 and 8 represent time axes.
　図７に基づいて説明すると、第２動作モードでは、制御回路３が、第２制御信号の位相を第１制御信号の位相よりも遅らせ、かつ、第１制御信号のデューティ比が第２制御信号のデューティ比よりも小さくなるように、スイッチング回路１およびスイッチング回路２を制御する。第１制御信号のデューティ比は、５０％よりも小さい。 Referring to FIG. 7, in the second operation mode, control circuit 3 delays the phase of the second control signal from the phase of the first control signal, and the duty ratio of the first control signal is the second control signal. The switching circuit 1 and the switching circuit 2 are controlled to be smaller than the duty ratio of The duty ratio of the first control signal is less than 50%.
　ここで、第２制御信号の位相を第１制御信号の位相よりも遅らせる場合、第１制御信号のデューティ比は、第１制御信号と第２制御信号との間の位相差Ｔｄに比例することが好ましい。以下、具体的に説明する。制御回路３は、動作モードを、例えば、第２動作モード（図４中のＡ５領域）から第１動作モード（図４中のＡ３領域）へ変更するとき、第１制御信号のデューティ比を位相差Ｔｄに比例させ、かつ、第２制御信号のデューティ比を数％（０％～５％の範囲内）とする。また、制御回路３は、動作モードを、例えば、第２動作モード（図４中のＡ５領域）から通常の動作モード（図４中のＡ１領域の右側領域）へ変更するとき、第１制御信号のデューティ比を位相差Ｔｄに比例させ、かつ、第２制御信号のデューティ比を５０％とする。また、第１制御信号の位相を第２制御信号の位相よりも遅らせる場合、第２制御信号のデューティ比は、位相差Ｔｄに比例することが好ましい。以下、具体的に説明する。制御回路３は、動作モードを、例えば、第２動作モード（図４中のＡ４領域）から第１動作モード（図４中のＡ２領域）へ変更するとき、第２制御信号のデューティ比を位相差Ｔｄに比例させ、かつ、第１制御信号のデューティ比を数％（０％～５％の範囲内）とする。また、制御回路３は、動作モードを、例えば、第２動作モード（図４中のＡ４領域）から通常の動作モード（図４中のＡ１領域の左側領域）へ変更するとき、第２制御信号のデューティ比を位相差Ｔｄに比例させ、かつ、第１制御信号のデューティ比を５０％とする。 Here, when the phase of the second control signal is delayed relative to the phase of the first control signal, the duty ratio of the first control signal is proportional to the phase difference Td between the first control signal and the second control signal. Is preferred. The details will be described below. Control circuit 3 changes the duty ratio of the first control signal when changing the operation mode, for example, from the second operation mode (A5 area in FIG. 4) to the first operation mode (A3 area in FIG. 4). The duty ratio of the second control signal is made several percent (within the range of 0% to 5%) in proportion to the phase difference Td. When the control circuit 3 changes the operation mode, for example, from the second operation mode (A5 area in FIG. 4) to the normal operation mode (right side area in A1 area in FIG. 4), the first control signal Is made proportional to the phase difference Td, and the duty ratio of the second control signal is made 50%. When the phase of the first control signal is delayed relative to the phase of the second control signal, the duty ratio of the second control signal is preferably proportional to the phase difference Td. The details will be described below. Control circuit 3 changes the duty ratio of the second control signal when changing the operation mode, for example, from the second operation mode (A4 area in FIG. 4) to the first operation mode (A2 area in FIG. 4). The duty ratio of the first control signal is made several percent (within the range of 0% to 5%) in proportion to the phase difference Td. When the control circuit 3 changes the operation mode, for example, from the second operation mode (A4 area in FIG. 4) to the normal operation mode (left side area of A1 area in FIG. 4), the second control signal The duty ratio of the first control signal is made 50% in proportion to the phase difference Td.
　これにより、制御回路３は、第２動作モードから第１動作モードに切り替わるときに、第１制御信号および第２制御信号の波形を一致させることが可能になる。また、制御回路３は、第２動作モードから通常の動作モードに切り替わるときに、第１制御信号および第２制御信号の波形を一致させることが可能になる。その結果、ＤＣ－ＤＣコンバータ１０では、制御回路３による動作モードの切替時に、出力波形が急変するのを回避することが可能となり、ＤＣ－ＤＣコンバータ１０の動作を安定させることが可能になる。 Thus, the control circuit 3 can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the first operation mode. Further, the control circuit 3 can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the normal operation mode. As a result, in the DC-DC converter 10, when the operation mode is switched by the control circuit 3, it is possible to avoid a sudden change in the output waveform, and it becomes possible to stabilize the operation of the DC-DC converter 10.
　制御回路３の記憶部３ａには、第１設定電圧比Ｒａ１（図４参照）と、第２設定電圧比Ｒａ２（図４参照）とが、記憶されている。第１設定電圧比Ｒａ１および第２設定電圧比Ｒａ２の各々は、上記電圧比と比較するための電圧比である。第２設定電圧比Ｒａ２は、第１設定電圧比Ｒａ１よりも大きい。 In the storage unit 3a of the control circuit 3, a first set voltage ratio Ra1 (see FIG. 4) and a second set voltage ratio Ra2 (see FIG. 4) are stored. Each of 1st setting voltage ratio Ra1 and 2nd setting voltage ratio Ra2 is a voltage ratio for comparing with the said voltage ratio. The second set voltage ratio Ra2 is larger than the first set voltage ratio Ra1.
　制御回路３は、後述の第１条件のとき、第１動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御する。第１条件は、上記電圧比が第１設定電圧比Ｒａ１よりも小さく、かつ、第２直流電圧Ｖｄ２から第１直流電圧Ｖｄ１に変換するとき（充電時）である（図４中のＡ２領域）。 The control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the first operation mode under a first condition described later. The first condition is that the voltage ratio is smaller than the first set voltage ratio Ra1 and the second DC voltage Vd2 is converted to the first DC voltage Vd1 (during charging) (area A2 in FIG. 4). .
　また、制御回路３は、後述の第２条件のとき、第１動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御する。第２条件は、上記電圧比が第２設定電圧比Ｒａ２よりも大きく、かつ、第１直流電圧Ｖｄ１から第２直流電圧Ｖｄ２に変換するとき（放電時）である（図４中のＡ３領域）。 Further, the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the first operation mode under the second condition described later. The second condition is that the voltage ratio is larger than the second set voltage ratio Ra2 and the first DC voltage Vd1 is converted to the second DC voltage Vd2 (during discharge) (area A3 in FIG. 4). .
　制御回路３は、後述の第３条件のとき、第２動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御する。第３条件は、上記電圧比が第１設定電圧比Ｒａ１よりも小さく、かつ、第１直流電圧Ｖｄ１から第２直流電圧Ｖｄ２に変換するとき（放電時）で、かつ、上述の設定電流の絶対値が所定値以下のときである（図４中のＡ４領域）。 The control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the second operation mode under a third condition described later. A third condition is when the voltage ratio is smaller than the first set voltage ratio Ra1 and the first DC voltage Vd1 is converted to the second DC voltage Vd2 (during discharge) and the absolute value of the set current described above This is when the value is equal to or less than the predetermined value (area A4 in FIG. 4).
　また、制御回路３は、後述の第４条件のとき、第２動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御する。第４条件は、上記電圧比が第２設定電圧比Ｒａ２よりも大きく、かつ、第２直流電圧Ｖｄ２から第１直流電圧Ｖｄ１に変換するとき（充電時）で、かつ、設定電流の絶対値が上記所定値以下のときである（図４中のＡ５領域）。 Further, the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 according to the second operation mode under a fourth condition described later. A fourth condition is that when the voltage ratio is larger than the second set voltage ratio Ra2 and the second DC voltage Vd2 is converted to the first DC voltage Vd1 (during charging), the absolute value of the set current is It is the time below the above-mentioned predetermined value (area A5 in FIG. 4).
　よって、ＤＣ－ＤＣコンバータ１０では、制御回路３が、通常の動作モードに限らず、第１動作モードと第２動作モードとの一方の特定動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御するように構成されている。これにより、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが許容範囲外まで変動する場合であっても、動作を安定させることが可能になる。 Therefore, in the DC-DC converter 10, the control circuit 3 is not limited to the normal operation mode, and the first switching circuit 1 and the second switching circuit 2 are selected according to one of the first operation mode and the second operation mode. Is configured to control. Thereby, in the DC-DC converter 10, the operation can be stabilized even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 fluctuate out of the allowable range. .
　なお、制御回路３は、第２動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御するときに、設定電流の絶対値が所定値以下のときを条件としているが、この条件に限らない。 When control circuit 3 controls first switching circuit 1 and second switching circuit 2 in the second operation mode, the condition is taken that the absolute value of the set current is equal to or less than the predetermined value, but this condition is limited. Absent.
　制御回路３は、第２動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御するときに、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２との一方および設定電流の積で得られる電力の絶対値が上記所定値以下のときを条件としてもよい。また、制御回路３は、第２動作モードにより第１スイッチング回路１および第２スイッチング回路２を制御するときに、第１制御信号と第２制御信号との間の位相差Ｔｄの絶対値が上記所定値以下のときを条件としてもよい。 When control circuit 3 controls first switching circuit 1 and second switching circuit 2 in the second operation mode, power obtained by the product of one of first DC voltage Vd1 and second DC voltage Vd2 and a set current The condition may be that the absolute value of is less than or equal to the predetermined value. Further, when the control circuit 3 controls the first switching circuit 1 and the second switching circuit 2 in the second operation mode, the absolute value of the phase difference Td between the first control signal and the second control signal is not The condition may be a time less than or equal to a predetermined value.
　また、制御回路３は、動作モードとして、第１動作モードと第２動作モードとの両方を有しているが、これに限らず、第１動作モードと第２動作モードとの一方を有していてもよい。 Further, although the control circuit 3 has both of the first operation mode and the second operation mode as an operation mode, the present invention is not limited to this, and has one of the first operation mode and the second operation mode. It may be
　ＤＣ－ＤＣコンバータ１０は、一対の接続端１ａ，１ｂ間に蓄電池１１が電気的に接続され、一対の接続端２ｃ，２ｄ間に直流電圧源１２が電気的に接続されているが、これに限らない。ＤＣ－ＤＣコンバータ１０は、一対の接続端１ａ，１ｂ間に直流電圧源１２が電気的に接続され、一対の接続端２ｃ，２ｄ間に蓄電池１１が電気的に接続されていてもよい。 In the DC-DC converter 10, the storage battery 11 is electrically connected between the pair of connection ends 1a and 1b, and the DC voltage source 12 is electrically connected between the pair of connection ends 2c and 2d. Not exclusively. In the DC-DC converter 10, the DC voltage source 12 may be electrically connected between the pair of connection ends 1a and 1b, and the storage battery 11 may be electrically connected between the pair of connection ends 2c and 2d.
　以上述べた実施形態から明らかなように、本発明に係る第１の態様のＤＣ－ＤＣコンバータ（１０）は、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）とを双方向に電圧変換を行うＤＣ－ＤＣコンバータである。ＤＣ－ＤＣコンバータ（１０）は、第１スイッチング素子（Ｑ１）を具備する第１スイッチング回路（１）と、インダクタ（Ｌ１）と、コンデンサ（Ｃ１）と、トランス（Ｔ１）とを備えている。また、ＤＣ－ＤＣコンバータ（１０）は、第２スイッチング素子（Ｑ５）を具備する第２スイッチング回路（２）と、第１スイッチング回路（１）および第２スイッチング回路（２）を制御する制御回路（３）とを備えている。第１スイッチング回路（１）は、第１直流電圧（Ｖｄ１）と第１交流電圧（Ｖａ１）とを双方向に電圧変換を行うように構成されている。第２スイッチング回路（２）は、第２交流電圧（Ｖａ２）と第２直流電圧（Ｖｄ２）とを双方向に電圧変換を行うように構成されている。トランス（Ｔ１）は、第１巻線（Ｎ１１）と第２巻線（Ｎ１２）とを備えている。第１巻線（Ｎ１１）と第２巻線（Ｎ１２）とは、磁気的に結合されている。第１スイッチング回路（１）における第１交流電圧（Ｖａ１）側の一対の接続端（１ｃ，１ｄ）間には、第１巻線（Ｎ１１）が電気的に接続されている。第２スイッチング回路（２）における第２交流電圧（Ｖａ２）側の一対の接続端（２ａ，２ｂ）間には、第２巻線（Ｎ１２）が電気的に接続されている。インダクタ（Ｌ１）とコンデンサ（Ｃ１）との直列回路は、第１スイッチング回路（１）における一対の接続端（１ｃ，１ｄ）間において、第１巻線（Ｎ１１）と電気的に直列接続されている。 As apparent from the above-described embodiment, the DC-DC converter (10) according to the first aspect of the present invention is a voltage in which the first DC voltage (Vd1) and the second DC voltage (Vd2) are bidirectionally supplied. It is a DC-DC converter that performs conversion. The DC-DC converter (10) includes a first switching circuit (1) including a first switching element (Q1), an inductor (L1), a capacitor (C1), and a transformer (T1). Further, the DC-DC converter (10) comprises a second switching circuit (2) having a second switching element (Q5), and a control circuit for controlling the first switching circuit (1) and the second switching circuit (2). And (3) are provided. The first switching circuit (1) is configured to perform voltage conversion between the first DC voltage (Vd1) and the first AC voltage (Va1) in both directions. The second switching circuit (2) is configured to perform voltage conversion between the second AC voltage (Va2) and the second DC voltage (Vd2) in both directions. The transformer (T1) includes a first winding (N11) and a second winding (N12). The first winding (N11) and the second winding (N12) are magnetically coupled. A first winding (N11) is electrically connected between the pair of connection ends (1c, 1d) on the first AC voltage (Va1) side in the first switching circuit (1). A second winding (N12) is electrically connected between the pair of connection ends (2a, 2b) on the second AC voltage (Va2) side in the second switching circuit (2). The series circuit of the inductor (L1) and the capacitor (C1) is electrically connected in series with the first winding (N11) between the pair of connection ends (1c, 1d) in the first switching circuit (1). There is.
　第１の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータにおける昇圧回路もしくは従来例２のＤＣ－ＤＣコンバータにおけるチョッパ回路を用いることなく、簡単な構成で双方向に電圧変換を行うことが可能となる。その結果、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を向上させることも可能となる。また、ＤＣ－ＤＣコンバータ（１０）では、従来例２のＤＣ－ＤＣコンバータにおけるチョッパ回路が不要となるので、従来例２のＤＣ－ＤＣコンバータに比べて、双方向の電圧変換において変換効率を向上させることが可能となる。すなわち、ＤＣ－ＤＣコンバータ（１０）では、双方向に電圧変換を行うことが可能で、かつ、双方向の電圧変換において変換効率を向上させることが可能となる。 According to the first aspect, the DC-DC converter (10) does not use the booster circuit in the DC-DC converter of Conventional Example 1 or the chopper circuit in the DC-DC converter of Conventional Example 2 and has a simple configuration. It is possible to perform voltage conversion in the As a result, in the DC-DC converter (10), it is also possible to improve the conversion efficiency as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Further, in the DC-DC converter (10), since the chopper circuit in the DC-DC converter of Conventional Example 2 becomes unnecessary, the conversion efficiency is improved in bidirectional voltage conversion as compared with the DC-DC converter of Conventional Example 2. It is possible to That is, in the DC-DC converter (10), voltage conversion can be performed bidirectionally, and conversion efficiency can be improved in bidirectional voltage conversion.
　本発明に係る第２の態様のＤＣ－ＤＣコンバータ（１０）では、第１の態様において、第１巻線（Ｎ１１）の巻線数を第２巻線（Ｎ１２）の巻線数で除算した値で表されるトランス（Ｔ１）の巻数比は、第１直流電圧（Ｖｄ１）の最大値を第２直流電圧（Ｖｄ２）の最小値で除算した値よりも小さく、かつ、第１直流電圧（Ｖｄ１）の最小値を第２直流電圧（Ｖｄ２）の最大値で除算した値よりも大きいことが好ましい。 In the DC-DC converter (10) according to the second aspect of the present invention, in the first aspect, the number of turns of the first winding (N11) is divided by the number of turns of the second winding (N12) The turns ratio of the transformer (T1) represented by the value is smaller than a value obtained by dividing the maximum value of the first DC voltage (Vd1) by the minimum value of the second DC voltage (Vd2), and the first DC voltage It is preferable that the minimum value of Vd1) be larger than a value obtained by dividing the minimum value of the second DC voltage (Vd2).
　第２の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧（Ｖｄ１）の電圧値と第２直流電圧（Ｖｄ２）の電圧値とが一定の範囲内でそれぞれ変動する場合であっても、第１変換効率と、第２変換効率との差を抑制することが可能となる。 According to the second aspect, in the DC-DC converter (10), the voltage value of the first DC voltage (Vd1) and the voltage value of the second DC voltage (Vd2) each fluctuate within a predetermined range. Even if there is, it is possible to suppress the difference between the first conversion efficiency and the second conversion efficiency.
　本発明に係る第３の態様のＤＣ－ＤＣコンバータ（１０）では、第１の態様において、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）との一方は、蓄電池（１１）の端子間電圧であることが好ましい。第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）との他方は、直流電圧源（１２）の端子間電圧であることが好ましい。トランス（Ｔ１）の巻数比は、直流電圧源（１２）の端子間電圧を、蓄電池（１１）における充電時の端子間電圧と蓄電池（１１）における放電時の端子間電圧との平均値で除算した値を基準値とする所定範囲内の値であることが好ましい。 In the DC-DC converter (10) according to the third aspect of the present invention, in the first aspect, one of the first DC voltage (Vd1) and the second DC voltage (Vd2) is a terminal of the storage battery (11) It is preferable to be an inter-voltage. Preferably, the other of the first DC voltage (Vd1) and the second DC voltage (Vd2) is a voltage between terminals of the DC voltage source (12). The turns ratio of the transformer (T1) is obtained by dividing the inter-terminal voltage of the DC voltage source (12) by the average value of the inter-terminal voltage during charging in the storage battery (11) and the inter-terminal voltage during discharging in the storage battery (11). It is preferable that it is a value within a predetermined range in which the obtained value is a reference value.
　第３の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１変換効率と、第２変換効率との差を抑制することが可能となる。 According to the third aspect, the DC-DC converter (10) can suppress the difference between the first conversion efficiency and the second conversion efficiency.
　本発明に係る第４の態様のＤＣ－ＤＣコンバータ（１０）では、第１の態様ないし第３の態様のいずれか１つの態様において、制御回路（３）は、第１スイッチング素子（Ｑ１）を制御する第１制御信号により第１スイッチング回路（１）を制御するように構成されていることが好ましい。また、制御回路（３）は、第２スイッチング素子（Ｑ５）を制御する第２制御信号により第２スイッチング回路２を制御するように構成されていることが好ましい。第１制御信号および第２制御信号の各々は、ＰＷＭ信号であることが好ましい。第１制御信号と第２制御信号とは、同じ周波数、かつ、同じデューティ比であることが好ましい。制御回路（３）は、第１制御信号と第２制御信号との間の位相差（Ｔｄ）を可変とするように、第１制御信号の位相と第２制御信号の位相とを調節するように構成されていることが好ましい。 In the DC-DC converter (10) of the fourth aspect according to the present invention, in any one of the first to third aspects, the control circuit (3) comprises a first switching element (Q1). Preferably, the first switching circuit (1) is configured to be controlled by the first control signal to be controlled. The control circuit (3) is preferably configured to control the second switching circuit 2 by a second control signal that controls the second switching element (Q5). Preferably, each of the first control signal and the second control signal is a PWM signal. It is preferable that the first control signal and the second control signal have the same frequency and the same duty ratio. The control circuit (3) adjusts the phase of the first control signal and the phase of the second control signal so as to make the phase difference (Td) between the first control signal and the second control signal variable. It is preferable to be configured.
　第４の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）とを双方向に電圧変換を行うことが可能となる。また、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータにおける昇圧回路もしくは従来例２のＤＣ－ＤＣコンバータにおけるチョッパ回路を用いることなく、簡単な構成で双方向に電圧変換を行うことが可能となる。その結果、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を向上させることが可能となる。また、ＤＣ－ＤＣコンバータ（１０）では、従来例２のＤＣ－ＤＣコンバータにおけるチョッパ回路が不要となるので、従来例２のＤＣ－ＤＣコンバータに比べて、双方向の電圧変換において変換効率を向上させることが可能となる。すなわち、ＤＣ－ＤＣコンバータ（１０）では、双方向に電圧変換を行うことが可能で、かつ、双方向の電圧変換において変換効率を向上させることが可能となる。 According to the fourth aspect, in the DC-DC converter (10), voltage conversion can be performed bidirectionally between the first DC voltage (Vd1) and the second DC voltage (Vd2). Further, in the DC-DC converter (10), voltage conversion is performed bidirectionally with a simple configuration without using the booster circuit in the DC-DC converter of Conventional Example 1 or the chopper circuit in the DC-DC converter of Conventional Example 2. It becomes possible. As a result, in the DC-DC converter (10), the conversion efficiency can be improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Further, in the DC-DC converter (10), since the chopper circuit in the DC-DC converter of Conventional Example 2 becomes unnecessary, the conversion efficiency is improved in bidirectional voltage conversion as compared with the DC-DC converter of Conventional Example 2. It is possible to That is, in the DC-DC converter (10), voltage conversion can be performed bidirectionally, and conversion efficiency can be improved in bidirectional voltage conversion.
　本発明に係る第５の態様のＤＣ－ＤＣコンバータ（１０）では、第４の態様において、制御回路（３）は、第１制御信号と第２制御信号との一方の位相を、第１制御信号と第２制御信号との他方の位相よりも遅らせるように構成されていることが好ましい。 In the DC-DC converter (10) according to the fifth aspect of the present invention, in the fourth aspect, the control circuit (3) controls one of the phases of the first control signal and the second control signal as the first control. Preferably, it is configured to lag behind the other phase of the signal and the second control signal.
　第５の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）とを双方向に電圧変換を行うことが可能となる。 According to the fifth aspect, in the DC-DC converter (10), voltage conversion can be performed bidirectionally between the first DC voltage (Vd1) and the second DC voltage (Vd2).
　本発明に係る第６の態様のＤＣ－ＤＣコンバータ（１０）では、第５の態様において、第１制御信号および第２制御信号それぞれの周波数は、直列回路（４）の共振周波数以上であることが好ましい。 In the DC-DC converter (10) according to the sixth aspect of the present invention, in the fifth aspect, each frequency of the first control signal and the second control signal is equal to or higher than the resonance frequency of the series circuit (4). Is preferred.
　第６の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１スイッチング素子（Ｑ１）および第２スイッチング素子（Ｑ５）の各々が、ハードスイッチング動作するのを抑制することが可能となる。よって、ＤＣ－ＤＣコンバータ（１０）では、スイッチング損失を抑制することが可能となる。その結果、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より向上させることが可能となる。 According to the sixth aspect, in the DC-DC converter (10), hard switching operation of each of the first switching element (Q1) and the second switching element (Q5) can be suppressed. Therefore, in the DC-DC converter (10), it is possible to suppress the switching loss. As a result, in the DC-DC converter (10), the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
　本発明に係る第７の態様のＤＣ－ＤＣコンバータ（１０）では、第５の態様または第６の態様において、制御回路（３）は、第１制御信号と第２制御信号との間の位相差（Ｔｄ）が増加するとき、第１制御信号および第２制御信号それぞれの周波数を増加させることが好ましい。 In the DC-DC converter (10) of the seventh aspect according to the present invention, in the fifth aspect or the sixth aspect, the control circuit (3) controls the difference between the first control signal and the second control signal. When the phase difference (Td) increases, it is preferable to increase the frequency of each of the first control signal and the second control signal.
　第７の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、スイッチング損失を抑制することが可能となる。その結果、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より向上させることが可能となる。 According to the seventh aspect, the DC-DC converter (10) can suppress the switching loss. As a result, in the DC-DC converter (10), the conversion efficiency can be further improved as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2.
　本発明に係る第８の態様のＤＣ－ＤＣコンバータ（１０）では、第５の態様ないし第７の態様のいずれか１つの態様において、ＤＣ－ＤＣコンバータ（１０）は、直列回路（４）に流れる共振電流（Ｉｒ）の位相を検出する検出回路（５）を、更に備えていることが好ましい。制御回路（３）は、検出回路（５）により検出された共振電流（Ｉｒ）の位相に応じて、第１スイッチング回路（１）における一対の接続端（１ｃ，１ｄ）間もしくは第２スイッチング回路（２）における一対の接続端（２ａ，２ｂ）間の電圧の位相と、共振電流（Ｉｒ）の位相との位相差が小さくなるように、第１スイッチング回路（１）および第２スイッチング回路（２）のスイッチング周波数を制御するように構成されていることが好ましい。 In the DC-DC converter (10) according to the eighth aspect of the present invention, in any one of the fifth to seventh aspects, the DC-DC converter (10) is a series circuit (4). It is preferable to further include a detection circuit (5) for detecting the phase of the flowing resonance current (Ir). The control circuit (3) is responsive to the phase of the resonant current (Ir) detected by the detection circuit (5), between the pair of connection ends (1c, 1d) in the first switching circuit (1) or the second switching circuit The first switching circuit (1) and the second switching circuit (2) are arranged such that the phase difference between the phase of the voltage between the pair of connection ends (2a, 2b) in (2) and the phase of the resonant current (Ir) is reduced. Preferably, the switching frequency of 2) is controlled.
　第８の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より向上させることが可能となる。 According to the eighth aspect, the DC-DC converter (10) can further improve the conversion efficiency as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. .
　本発明に係る第９の態様のＤＣ－ＤＣコンバータ（１０）では、第８の態様において、検出回路（５）は、第１スイッチング回路（１）もしくは第２スイッチング回路（２）に流れる検出電流を検出するように構成されていることが好ましい。制御回路（３）は、検出回路（５）により検出された検出電流と、予め設定された設定電流との差が小さくなるように、第１制御信号と第２制御信号との間の位相差を制御するように構成されていることが好ましい。 In a DC-DC converter (10) according to a ninth aspect of the present invention, in the eighth aspect, the detection circuit (5) detects a detection current flowing through the first switching circuit (1) or the second switching circuit (2). Preferably, it is configured to detect The control circuit (3) sets the phase difference between the first control signal and the second control signal such that the difference between the detection current detected by the detection circuit (5) and the preset setting current is reduced. Preferably, it is configured to control
　第９の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、従来例１のＤＣ－ＤＣコンバータおよび従来例２のＤＣ－ＤＣコンバータに比べて、変換効率を、より一層向上させることが可能となる。 According to the ninth aspect, the DC-DC converter (10) can further improve the conversion efficiency as compared with the DC-DC converter of Conventional Example 1 and the DC-DC converter of Conventional Example 2. Become.
　本発明に係る第１０の態様のＤＣ－ＤＣコンバータ（１０）では、第９の態様において、検出回路（５）は、第１直流電圧（Ｖｄ１）および第２直流電圧（Ｖｄ２）を検出するように構成されていることが好ましい。制御回路（３）は、検出回路（５）により検出された第１直流電圧（Ｖｄ１）および第２直流電圧（Ｖｄ２）に基づいて、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）との電圧比を算出するように構成されていることが好ましい。制御回路（３）は、特定の制御を行う特定動作モードを有していることが好ましい。特定動作モードでは、制御回路（３）が、第２制御信号の位相を第１制御信号の位相よりも遅らせ、かつ、第１制御信号がオン状態のときに第２制御信号がオフ状態となるように、第１スイッチング回路（１）および第２スイッチング回路（２）を制御する。制御回路（３）に設けられた記憶部には、第１設定電圧比と、第１設定電圧比よりも大きい第２設定電圧比とが、記憶されていることが好ましい。制御回路（３）は、上記電圧比が第１設定電圧比よりも小さくかつ第２直流電圧（Ｖｄ２）から第１直流電圧（Ｖｄ１）に変換するときと、上記電圧比が第２設定電圧比よりも大きくかつ第１直流電圧（Ｖｄ１）から第２直流電圧（Ｖｄ２）に変換するときとのそれぞれにおいて、特定動作モードにより第１スイッチング回路（１）および第２スイッチング回路（２）を制御することが好ましい。 In a DC-DC converter (10) according to a tenth aspect of the present invention, in the ninth aspect, the detection circuit (5) detects the first DC voltage (Vd1) and the second DC voltage (Vd2). It is preferable to be configured. The control circuit (3) generates a first DC voltage (Vd1) and a second DC voltage (Vd2) based on the first DC voltage (Vd1) and the second DC voltage (Vd2) detected by the detection circuit (5). Preferably, it is configured to calculate a voltage ratio of The control circuit (3) preferably has a specific operation mode for performing specific control. In the specific operation mode, the control circuit (3) delays the phase of the second control signal relative to the phase of the first control signal, and the second control signal is turned off when the first control signal is on. Thus, the first switching circuit (1) and the second switching circuit (2) are controlled. It is preferable that a first set voltage ratio and a second set voltage ratio larger than the first set voltage ratio be stored in the storage unit provided in the control circuit (3). When the voltage ratio is smaller than the first set voltage ratio and the second DC voltage (Vd2) is converted to the first DC voltage (Vd1), the control circuit (3) sets the second voltage ratio to the second set voltage ratio. The first switching circuit (1) and the second switching circuit (2) are controlled according to the specific operation mode, each being larger than and converting from the first DC voltage (Vd1) to the second DC voltage (Vd2) Is preferred.
　第１０の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが一定の範囲内で変動しない場合であっても、動作を安定させることが可能になる。すなわち、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とが変動する許容範囲に制約がなくなり、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とが変動する許容範囲を拡張することが可能になる。 According to the tenth aspect, the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to stabilize the That is, in the DC-DC converter 10, there is no restriction on the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate, and the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate is expanded. It will be possible to
　本発明に係る第１１の態様のＤＣ－ＤＣコンバータ（１０）では、第１０の態様において、制御回路（３）は、特定動作モードである第１動作モードとは異なる、第２動作モードを有していることが好ましい。第２動作モードでは、制御回路（３）が、第２制御信号の位相を第１制御信号の位相よりも遅らせ、かつ、第１制御信号のデューティ比が第２制御信号のデューティ比よりも小さくなるように、第１スイッチング回路（１）および第２スイッチング回路（２）を制御する。制御回路（３）は、上記電圧比が第１設定電圧比よりも小さくかつ第１直流電圧（Ｖｄ１）から第２直流電圧（Ｖｄ２）に変換する場合と、上記電圧比が第２設定電圧比よりも大きくかつ第２直流電圧（Ｖｄ２）から第１直流電圧（Ｖｄ１）に変換する場合とのそれぞれで、かつ、上記設定電流、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）との一方および上記設定電流の積で得られる電力、第１制御信号と第２制御信号との間の位相差（Ｔｄ）のいずれかの絶対値が所定値以下のとき、第２動作モードにより第１スイッチング回路（１）および第２スイッチング回路（２）を制御することが好ましい。 In a DC-DC converter (10) according to an eleventh aspect of the present invention, in the tenth aspect, the control circuit (3) has a second operation mode different from the first operation mode which is the specific operation mode. Is preferred. In the second operation mode, the control circuit (3) delays the phase of the second control signal relative to the phase of the first control signal, and the duty ratio of the first control signal is smaller than the duty ratio of the second control signal To control the first switching circuit (1) and the second switching circuit (2). When the voltage ratio is smaller than the first set voltage ratio and the first direct current voltage (Vd1) is converted to the second direct current voltage (Vd2), the control circuit (3) generates the second set voltage ratio as the second set voltage ratio. The setting current, the first DC voltage (Vd1) and the second DC voltage (Vd2) are larger than the above and when converting from the second DC voltage (Vd2) to the first DC voltage (Vd1). When the absolute value of either the power obtained by the product of one of the above and the setting current or the phase difference (Td) between the first control signal and the second control signal is less than a predetermined value, the second operation mode Preferably, the first switching circuit (1) and the second switching circuit (2) are controlled.
　第１１の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが一定の範囲内で変動しない場合であっても、動作をより安定させることが可能になる。よって、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とが変動する許容範囲を、より拡張することが可能になる。 According to the eleventh aspect, the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to make it more stable. Therefore, in the DC-DC converter 10, it is possible to further extend the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate.
　本発明に係る第１２の態様のＤＣ－ＤＣコンバータ（１０）では、第１１の態様において、第１制御信号のデューティ比は、第１制御信号と第２制御信号との間の位相差（Ｔｄ）に比例することが好ましい。 In the DC-DC converter (10) of the twelfth aspect according to the present invention, in the eleventh aspect, the duty ratio of the first control signal is a phase difference (Td) between the first control signal and the second control signal. It is preferable to be proportional to
　第１２の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、制御回路（３）は、第２動作モードから第１動作モードに切り替わるときに、第１制御信号および第２制御信号の波形を一致させることが可能になる。また、制御回路（３）は、第２動作モードから通常の動作モードに切り替わるときに、第１制御信号および第２制御信号の波形を一致させることが可能になる。その結果、ＤＣ－ＤＣコンバータ（１０）では、制御回路（３）による動作モードの切替時に、出力波形が急変するのを回避することが可能となり、ＤＣ－ＤＣコンバータ（１０）の動作を安定させることが可能になる。 According to the twelfth aspect, in the DC-DC converter (10), the control circuit (3) generates the waveforms of the first control signal and the second control signal when switching from the second operation mode to the first operation mode. It becomes possible to match. Further, the control circuit (3) can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the normal operation mode. As a result, in the DC-DC converter (10), it is possible to avoid a sudden change in the output waveform when the operation mode is switched by the control circuit (3), and the operation of the DC-DC converter (10) is stabilized. It becomes possible.
　本発明に係る第１３の態様のＤＣ－ＤＣコンバータ（１０）では、第９の態様において、検出回路（５）は、第１直流電圧（Ｖｄ１）および第２直流電圧（Ｖｄ２）を検出するように構成されていることが好ましい。制御回路（３）は、検出回路（５）により検出された第１直流電圧（Ｖｄ１）および第２直流電圧（Ｖｄ２）に基づいて、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）との電圧比を算出するように構成されていることが好ましい。制御回路（３）は、特定の制御を行う特定動作モードを有していることが好ましい。特定動作モードでは、制御回路（３）が、第１制御信号の位相を第２制御信号の位相よりも遅らせ、かつ、第２制御信号がオン状態のときに第１制御信号がオフ状態となるように、第１スイッチング回路（１）および第２スイッチング回路（２）を制御する。制御回路（３）に設けられた記憶部には、第１設定電圧比と、第１設定電圧比よりも大きい第２設定電圧比とが、記憶されていることが好ましい。制御回路（３）は、上記電圧比が第１設定電圧比よりも小さくかつ第２直流電圧（Ｖｄ２）から第１直流電圧（Ｖｄ１）に変換するときと、上記電圧比が第２設定電圧比よりも大きくかつ第１直流電圧（Ｖｄ１）から第２直流電圧（Ｖｄ２）に変換するときとのそれぞれにおいて、特定動作モードにより第１スイッチング回路（１）および第２スイッチング回路（２）を制御することが好ましい。 In a DC-DC converter (10) according to a thirteenth aspect of the present invention, in the ninth aspect, the detection circuit (5) detects the first DC voltage (Vd1) and the second DC voltage (Vd2). It is preferable to be configured. The control circuit (3) generates a first DC voltage (Vd1) and a second DC voltage (Vd2) based on the first DC voltage (Vd1) and the second DC voltage (Vd2) detected by the detection circuit (5). Preferably, it is configured to calculate a voltage ratio of The control circuit (3) preferably has a specific operation mode for performing specific control. In the specific operation mode, the control circuit (3) delays the phase of the first control signal relative to the phase of the second control signal, and the first control signal is turned off when the second control signal is on. Thus, the first switching circuit (1) and the second switching circuit (2) are controlled. It is preferable that a first set voltage ratio and a second set voltage ratio larger than the first set voltage ratio be stored in the storage unit provided in the control circuit (3). When the voltage ratio is smaller than the first set voltage ratio and the second DC voltage (Vd2) is converted to the first DC voltage (Vd1), the control circuit (3) sets the second voltage ratio to the second set voltage ratio. The first switching circuit (1) and the second switching circuit (2) are controlled according to the specific operation mode, each being larger than and converting from the first DC voltage (Vd1) to the second DC voltage (Vd2) Is preferred.
　第１３の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが一定の範囲内で変動しない場合であっても、動作を安定させることが可能になる。すなわち、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とが変動する許容範囲に制約がなくなり、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とが変動する許容範囲を拡張することが可能になる。 According to the thirteenth aspect, the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to stabilize the That is, in the DC-DC converter 10, there is no restriction on the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate, and the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate is expanded. It will be possible to
　本発明に係る第１４の態様のＤＣ－ＤＣコンバータ（１０）では、第１３の態様において、制御回路（３）は、特定動作モードである第１動作モードとは異なる、第２動作モードを有していることが好ましい。第２動作モードでは、制御回路（３）が、第１制御信号の位相を第２制御信号の位相よりも遅らせ、かつ、第２制御信号のデューティ比が第１制御信号のデューティ比よりも小さくなるように、第１スイッチング回路（１）および第２スイッチング回路（２）を制御する。制御回路（３）は、上記電圧比が第１設定電圧比よりも小さくかつ第１直流電圧（Ｖｄ１）から第２直流電圧（Ｖｄ２）に変換する場合と、上記電圧比が第２設定電圧比よりも大きくかつ第２直流電圧（Ｖｄ２）から第１直流電圧（Ｖｄ１）に変換する場合とのそれぞれで、かつ、上記設定電流、第１直流電圧（Ｖｄ１）と第２直流電圧（Ｖｄ２）との一方および上記設定電流の積で得られる電力、第１制御信号と第２制御信号との間の位相差（Ｔｄ）のいずれかの絶対値が所定値以下のとき、第２動作モードにより第１スイッチング回路（１）および第２スイッチング回路（２）を制御することが好ましい。 In the DC-DC converter (10) of the fourteenth aspect according to the present invention, in the thirteenth aspect, the control circuit (3) has a second operation mode different from the first operation mode which is the specific operation mode. Is preferred. In the second operation mode, the control circuit (3) delays the phase of the first control signal relative to the phase of the second control signal, and the duty ratio of the second control signal is smaller than the duty ratio of the first control signal To control the first switching circuit (1) and the second switching circuit (2). When the voltage ratio is smaller than the first set voltage ratio and the first direct current voltage (Vd1) is converted to the second direct current voltage (Vd2), the control circuit (3) generates the second set voltage ratio as the second set voltage ratio. The setting current, the first DC voltage (Vd1) and the second DC voltage (Vd2) are larger than the above and when converting from the second DC voltage (Vd2) to the first DC voltage (Vd1). When the absolute value of either the power obtained by the product of one of the above and the setting current or the phase difference (Td) between the first control signal and the second control signal is less than a predetermined value, the second operation mode Preferably, the first switching circuit (1) and the second switching circuit (2) are controlled.
　第１４の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、第１直流電圧Ｖｄ１の電圧値と第２直流電圧Ｖｄ２の電圧値とが一定の範囲内で変動しない場合であっても、動作をより安定させることが可能になる。よって、ＤＣ－ＤＣコンバータ１０では、第１直流電圧Ｖｄ１と第２直流電圧Ｖｄ２とが変動する許容範囲を、より拡張することが可能になる。 According to the fourteenth aspect, the DC-DC converter (10) operates even when the voltage value of the first DC voltage Vd1 and the voltage value of the second DC voltage Vd2 do not fluctuate within a certain range. It becomes possible to make it more stable. Therefore, in the DC-DC converter 10, it is possible to further extend the allowable range in which the first DC voltage Vd1 and the second DC voltage Vd2 fluctuate.
　本発明に係る第１５の態様のＤＣ－ＤＣコンバータ（１０）では、第１４の態様において、第２制御信号のデューティ比は、第１制御信号と第２制御信号との間の位相差（Ｔｄ）に比例することが好ましい。 In the DC-DC converter (10) of the fifteenth aspect according to the present invention, in the fourteenth aspect, the duty ratio of the second control signal is a phase difference (Td) between the first control signal and the second control signal. It is preferable to be proportional to
　第１５の態様によれば、ＤＣ－ＤＣコンバータ（１０）では、制御回路（３）は、第２動作モードから第１動作モードに切り替わるときに、第１制御信号および第２制御信号の波形を一致させることが可能になる。また、制御回路（３）は、第２動作モードから通常の動作モードに切り替わるときに、第１制御信号および第２制御信号の波形を一致させることが可能になる。その結果、ＤＣ－ＤＣコンバータ（１０）では、制御回路（３）による動作モードの切替時に、出力波形が急変するのを回避することが可能となり、ＤＣ－ＤＣコンバータ（１０）の動作を安定させることが可能になる。 According to the fifteenth aspect, in the DC-DC converter (10), the control circuit (3) generates the waveforms of the first control signal and the second control signal when switching from the second operation mode to the first operation mode. It becomes possible to match. Further, the control circuit (3) can match the waveforms of the first control signal and the second control signal when switching from the second operation mode to the normal operation mode. As a result, in the DC-DC converter (10), it is possible to avoid a sudden change in the output waveform when the operation mode is switched by the control circuit (3), and the operation of the DC-DC converter (10) is stabilized. It becomes possible.
　本発明を幾つかの好ましい実施形態によって記述したが、この発明の本来の精神および範囲、即ち請求の範囲を逸脱することなく、当業者によって様々な修正および変形が可能である。 Although the present invention has been described in terms of several preferred embodiments, various modifications and variations can be made by those skilled in the art without departing from the true spirit and scope of the present invention, ie, the claims.

Claims (15)

  1. 　第１直流電圧と第２直流電圧とを双方向に電圧変換を行うＤＣ－ＤＣコンバータであって、
    　第１スイッチング素子を具備する第１スイッチング回路と、インダクタと、コンデンサと、トランスと、第２スイッチング素子を具備する第２スイッチング回路と、前記第１スイッチング回路および前記第２スイッチング回路を制御する制御回路とを備え、
    　前記第１スイッチング回路は、前記第１直流電圧と第１交流電圧とを双方向に電圧変換を行うように構成され、
    　前記第２スイッチング回路は、第２交流電圧と前記第２直流電圧とを双方向に電圧変換を行うように構成され、
    　前記トランスは、第１巻線と第２巻線とを備え、前記第１巻線と前記第２巻線とは、磁気的に結合され、
    　前記第１スイッチング回路における前記第１交流電圧側の一対の接続端間には、前記第１巻線が電気的に接続され、
    　前記第２スイッチング回路における前記第２交流電圧側の一対の接続端間には、前記第２巻線が電気的に接続され、
    　前記インダクタと前記コンデンサとの直列回路は、前記第１スイッチング回路における前記一対の接続端間において、前記第１巻線と電気的に直列接続されている
    　ことを特徴とするＤＣ－ＤＣコンバータ。     A DC-DC converter that performs voltage conversion between a first DC voltage and a second DC voltage in both directions,
    Control to control a first switching circuit comprising a first switching element, an inductor, a capacitor, a transformer, a second switching circuit comprising a second switching element, and the first switching circuit and the second switching circuit Equipped with a circuit,
    The first switching circuit is configured to perform voltage conversion between the first DC voltage and the first AC voltage in both directions,
    The second switching circuit is configured to perform voltage conversion between a second AC voltage and the second DC voltage in both directions,
    The transformer includes a first winding and a second winding, and the first winding and the second winding are magnetically coupled.
    The first winding is electrically connected between the pair of connection ends on the first alternating voltage side in the first switching circuit,
    The second winding is electrically connected between the pair of connection ends on the second AC voltage side in the second switching circuit,
    A DC-DC converter characterized in that a series circuit of the inductor and the capacitor is electrically connected in series with the first winding between the pair of connection ends in the first switching circuit.
  2. 　前記第１巻線の巻線数を前記第２巻線の巻線数で除算した値で表される前記トランスの巻数比は、前記第１直流電圧の最大値を前記第２直流電圧の最小値で除算した値よりも小さく、かつ、前記第１直流電圧の最小値を前記第２直流電圧の最大値で除算した値よりも大きい
    　ことを特徴とする請求項１記載のＤＣ－ＤＣコンバータ。     The turns ratio of the transformer represented by a value obtained by dividing the number of turns of the first winding by the number of turns of the second winding is the maximum value of the first direct current voltage and the minimum value of the second direct current voltage. The DC-DC converter according to claim 1, wherein the DC-DC converter is smaller than a value divided by a value and larger than a value obtained by dividing the minimum value of the first DC voltage by the maximum value of the second DC voltage.
  3. 　前記第１直流電圧と前記第２直流電圧との一方は、蓄電池の端子間電圧であり、
    　前記第１直流電圧と前記第２直流電圧との他方は、直流電圧源の端子間電圧であり、
    　前記第１巻線の巻線数を前記第２巻線の巻線数で除算した値で表される前記トランスの巻数比は、前記直流電圧源の端子間電圧を、前記蓄電池における充電時の端子間電圧と前記蓄電池における放電時の端子間電圧との平均値で除算した値を基準値とする所定範囲内の値である
    　ことを特徴とする請求項１記載のＤＣ－ＤＣコンバータ。     One of the first DC voltage and the second DC voltage is a voltage between terminals of the storage battery,
    The other of the first DC voltage and the second DC voltage is a voltage between terminals of a DC voltage source,
    The turns ratio of the transformer, which is represented by a value obtained by dividing the number of turns of the first winding by the number of turns of the second winding, determines the voltage between terminals of the DC voltage source when charging the storage battery. The DC-DC converter according to claim 1, wherein the DC-DC converter is a value within a predetermined range using a value obtained by dividing an average value of an inter-terminal voltage and an inter-terminal voltage at the time of discharge in the storage battery.
  4. 　前記制御回路は、前記第１スイッチング素子を制御する第１制御信号により前記第１スイッチング回路を制御し、かつ、前記第２スイッチング素子を制御する第２制御信号により前記第２スイッチング回路を制御するように構成され、
    　前記第１制御信号および前記第２制御信号の各々は、ＰＷＭ信号であり、前記第１制御信号と前記第２制御信号とは、同じ周波数、かつ、同じデューティ比であり、
    　前記制御回路は、前記第１制御信号と前記第２制御信号との間の位相差を可変とするように、前記第１制御信号の位相と前記第２制御信号の位相とを調節するように構成されている
    　ことを特徴とする請求項１ないし請求項３のいずれか１項に記載のＤＣ－ＤＣコンバータ。     The control circuit controls the first switching circuit by a first control signal that controls the first switching element, and controls the second switching circuit by a second control signal that controls the second switching element. Configured as
    Each of the first control signal and the second control signal is a PWM signal, and the first control signal and the second control signal have the same frequency and the same duty ratio,
    The control circuit adjusts the phase of the first control signal and the phase of the second control signal such that the phase difference between the first control signal and the second control signal is variable. The DC-DC converter according to any one of claims 1 to 3, which is configured.
  5. 　前記制御回路は、前記第１制御信号と前記第２制御信号との一方の位相を、前記第１制御信号と前記第２制御信号との他方の位相よりも遅らせるように構成されている
    　ことを特徴とする請求項４記載のＤＣ－ＤＣコンバータ。     The control circuit is configured to delay the phase of one of the first control signal and the second control signal more than the other phase of the first control signal and the second control signal. The DC-DC converter according to claim 4, characterized in that:
  6. 　前記第１制御信号および前記第２制御信号それぞれの周波数は、前記直列回路の共振周波数以上である
    　ことを特徴とする請求項５記載のＤＣ－ＤＣコンバータ。     The DC-DC converter according to claim 5, wherein the frequency of each of the first control signal and the second control signal is equal to or higher than a resonance frequency of the series circuit.
  7. 　前記制御回路は、前記第１制御信号と前記第２制御信号との間の位相差が増加するとき、前記第１制御信号および前記第２制御信号それぞれの周波数を増加させる
    　ことを特徴とする請求項５または請求項６記載のＤＣ－ＤＣコンバータ。     The control circuit increases the frequency of each of the first control signal and the second control signal when the phase difference between the first control signal and the second control signal increases. A DC-DC converter according to claim 5 or 6.
  8. 　前記直列回路に流れる共振電流の位相を検出する検出回路を、更に備え、
    　前記制御回路は、前記検出回路により検出された前記共振電流の位相に応じて、前記第１スイッチング回路もしくは前記第２スイッチング回路における前記一対の接続端間の電圧の位相と、前記共振電流の位相との位相差が小さくなるように、前記第１スイッチング回路および前記第２スイッチング回路のスイッチング周波数を制御するように構成されている
    　ことを特徴とする請求項５ないし請求項７のいずれか１項に記載のＤＣ－ＤＣコンバータ。     The circuit further comprises a detection circuit that detects the phase of the resonant current flowing in the series circuit,
    The control circuit controls a phase of a voltage between the pair of connection terminals in the first switching circuit or the second switching circuit and a phase of the resonance current according to the phase of the resonance current detected by the detection circuit. The switching frequency of the first switching circuit and the second switching circuit is controlled so as to reduce the phase difference between the first switching circuit and the second switching circuit. DC-DC converter as described in.
  9. 　前記検出回路は、前記第１スイッチング回路もしくは前記第２スイッチング回路に流れる検出電流を検出するように構成され、
    　前記制御回路は、前記検出回路により検出された前記検出電流と、予め設定された設定電流との差が小さくなるように、前記第１制御信号と前記第２制御信号との間の位相差を制御するように構成されている
    　ことを特徴とする請求項８記載のＤＣ－ＤＣコンバータ。     The detection circuit is configured to detect a detection current flowing in the first switching circuit or the second switching circuit,
    The control circuit sets a phase difference between the first control signal and the second control signal such that a difference between the detection current detected by the detection circuit and a preset setting current is reduced. The DC-DC converter according to claim 8, wherein the DC-DC converter is configured to control.
  10. 　前記検出回路は、前記第１直流電圧および前記第２直流電圧を検出するように構成され、
    　前記制御回路は、前記検出回路により検出された前記第１直流電圧および前記第２直流電圧に基づいて、前記第１直流電圧と前記第２直流電圧との電圧比を算出するように構成され、
    　前記制御回路は、特定の制御を行う特定動作モードを有し、
    　前記特定動作モードでは、前記制御回路が、前記第２制御信号の位相を前記第１制御信号の位相よりも遅らせ、かつ、前記第１制御信号がオン状態のときに前記第２制御信号がオフ状態となるように、前記第１スイッチング回路および前記第２スイッチング回路を制御し、
    　前記制御回路に設けられた記憶部には、第１設定電圧比と、前記第１設定電圧比よりも大きい第２設定電圧比とが、記憶され、
    　前記制御回路は、前記電圧比が前記第１設定電圧比よりも小さくかつ前記第２直流電圧から前記第１直流電圧に変換するときと、前記電圧比が前記第２設定電圧比よりも大きくかつ前記第１直流電圧から前記第２直流電圧に変換するときとのそれぞれにおいて、前記特定動作モードにより前記第１スイッチング回路および前記第２スイッチング回路を制御する
    　ことを特徴とする請求項９記載のＤＣ－ＤＣコンバータ。     The detection circuit is configured to detect the first DC voltage and the second DC voltage.
    The control circuit is configured to calculate a voltage ratio between the first DC voltage and the second DC voltage based on the first DC voltage and the second DC voltage detected by the detection circuit.
    The control circuit has a specific operation mode for performing specific control,
    In the specific operation mode, the control circuit delays the phase of the second control signal relative to the phase of the first control signal, and the second control signal is turned off when the first control signal is in the on state. Control the first switching circuit and the second switching circuit to be in a state;
    A first set voltage ratio and a second set voltage ratio larger than the first set voltage ratio are stored in a storage unit provided in the control circuit,
    When the voltage ratio is smaller than the first set voltage ratio and the second DC voltage is converted to the first DC voltage, the voltage ratio is larger than the second set voltage ratio and the control circuit 10. The DC according to claim 9, characterized in that the first switching circuit and the second switching circuit are controlled according to the specific operation mode at each of the time of converting the first DC voltage to the second DC voltage. -DC converter.
  11. 　前記制御回路は、前記特定動作モードである第１動作モードとは異なる、第２動作モードを有し、
    　前記第２動作モードでは、前記制御回路が、前記第２制御信号の位相を前記第１制御信号の位相よりも遅らせ、かつ、前記第１制御信号のデューティ比が前記第２制御信号のデューティ比よりも小さくなるように、前記第１スイッチング回路および前記第２スイッチング回路を制御し、
    　前記制御回路は、前記電圧比が前記第１設定電圧比よりも小さくかつ前記第１直流電圧から前記第２直流電圧に変換する場合と、前記電圧比が前記第２設定電圧比よりも大きくかつ前記第２直流電圧から前記第１直流電圧に変換する場合とのそれぞれで、かつ、前記設定電流、前記第１直流電圧と前記第２直流電圧との一方および前記設定電流の積で得られる電力、前記第１制御信号と前記第２制御信号との間の位相差のいずれかの絶対値が所定値以下のとき、前記第２動作モードにより前記第１スイッチング回路および前記第２スイッチング回路を制御する
    　ことを特徴とする請求項１０記載のＤＣ－ＤＣコンバータ。     The control circuit has a second operation mode different from the first operation mode which is the specific operation mode,
    In the second operation mode, the control circuit delays the phase of the second control signal relative to the phase of the first control signal, and the duty ratio of the first control signal is the duty ratio of the second control signal. Controlling the first switching circuit and the second switching circuit to be smaller than
    When the voltage ratio is smaller than the first set voltage ratio and the first DC voltage is converted to the second DC voltage, the voltage ratio is larger than the second set voltage ratio and the control circuit The electric power obtained by the product of one of the setting current, one of the first DC voltage and the second DC voltage, and the setting current in each of the cases where the second DC voltage is converted to the first DC voltage Controlling the first switching circuit and the second switching circuit according to the second operation mode when an absolute value of any of phase differences between the first control signal and the second control signal is equal to or less than a predetermined value The DC-DC converter according to claim 10, characterized in that:
  12. 　前記第１制御信号のデューティ比は、前記第１制御信号と前記第２制御信号との間の位相差に比例する
    　ことを特徴とする請求項１１記載のＤＣ－ＤＣコンバータ。     The DC-DC converter according to claim 11, wherein a duty ratio of the first control signal is proportional to a phase difference between the first control signal and the second control signal.
  13. 　前記検出回路は、前記第１直流電圧および前記第２直流電圧を検出するように構成され、
    　前記制御回路は、前記検出回路により検出された前記第１直流電圧および前記第２直流電圧に基づいて、前記第１直流電圧と前記第２直流電圧との電圧比を算出するように構成され、
    　前記制御回路は、特定の制御を行う特定動作モードを有し、
    　前記特定動作モードでは、前記制御回路が、前記第１制御信号の位相を前記第２制御信号の位相よりも遅らせ、かつ、前記第２制御信号がオン状態のときに前記第１制御信号がオフ状態となるように、前記第１スイッチング回路および前記第２スイッチング回路を制御し、
    　前記制御回路に設けられた記憶部には、第１設定電圧比と、前記第１設定電圧比よりも大きい第２設定電圧比とが、記憶され、
    　前記制御回路は、前記電圧比が前記第１設定電圧比よりも小さくかつ前記第２直流電圧から前記第１直流電圧に変換するときと、前記電圧比が前記第２設定電圧比よりも大きくかつ前記第１直流電圧から前記第２直流電圧に変換するときとのそれぞれにおいて、前記特定動作モードにより前記第１スイッチング回路および前記第２スイッチング回路を制御する
    　ことを特徴とする請求項９記載のＤＣ－ＤＣコンバータ。     The detection circuit is configured to detect the first DC voltage and the second DC voltage.
    The control circuit is configured to calculate a voltage ratio between the first DC voltage and the second DC voltage based on the first DC voltage and the second DC voltage detected by the detection circuit.
    The control circuit has a specific operation mode for performing specific control,
    In the specific operation mode, the control circuit delays the phase of the first control signal relative to the phase of the second control signal, and the first control signal is off when the second control signal is in the on state. Control the first switching circuit and the second switching circuit to be in a state;
    A first set voltage ratio and a second set voltage ratio larger than the first set voltage ratio are stored in a storage unit provided in the control circuit,
    When the voltage ratio is smaller than the first set voltage ratio and the second DC voltage is converted to the first DC voltage, the voltage ratio is larger than the second set voltage ratio and the control circuit 10. The DC according to claim 9, characterized in that the first switching circuit and the second switching circuit are controlled according to the specific operation mode at each of the time of converting the first DC voltage to the second DC voltage. -DC converter.
  14. 　前記制御回路は、前記特定動作モードである第１動作モードとは異なる、第２動作モードを有し、
    　前記第２動作モードでは、前記制御回路が、前記第１制御信号の位相を前記第２制御信号の位相よりも遅らせ、かつ、前記第２制御信号のデューティ比が前記第１制御信号のデューティ比よりも小さくなるように、前記第１スイッチング回路および前記第２スイッチング回路を制御し、
    　前記制御回路は、前記電圧比が前記第１設定電圧比よりも小さくかつ前記第１直流電圧から前記第２直流電圧に変換する場合と、前記電圧比が前記第２設定電圧比よりも大きくかつ前記第２直流電圧から前記第１直流電圧に変換する場合とのそれぞれで、かつ、前記設定電流、前記第１直流電圧と前記第２直流電圧との一方および前記設定電流の積で得られる電力、前記第１制御信号と前記第２制御信号との間の位相差のいずれかの絶対値が所定値以下のとき、前記第２動作モードにより前記第１スイッチング回路および前記第２スイッチング回路を制御する
    　ことを特徴とする請求項１３記載のＤＣ－ＤＣコンバータ。     The control circuit has a second operation mode different from the first operation mode which is the specific operation mode,
    In the second operation mode, the control circuit delays the phase of the first control signal relative to the phase of the second control signal, and the duty ratio of the second control signal is the duty ratio of the first control signal. Controlling the first switching circuit and the second switching circuit to be smaller than
    When the voltage ratio is smaller than the first set voltage ratio and the first DC voltage is converted to the second DC voltage, the voltage ratio is larger than the second set voltage ratio and the control circuit The electric power obtained by the product of one of the setting current, one of the first DC voltage and the second DC voltage, and the setting current in each of the cases where the second DC voltage is converted to the first DC voltage Controlling the first switching circuit and the second switching circuit according to the second operation mode when an absolute value of any of phase differences between the first control signal and the second control signal is equal to or less than a predetermined value The DC-DC converter according to claim 13, characterized in that:
  15. 　前記第２制御信号のデューティ比は、前記第１制御信号と前記第２制御信号との間の位相差に比例する
    　ことを特徴とする請求項１４記載のＤＣ－ＤＣコンバータ。     The DC-DC converter according to claim 14, wherein a duty ratio of the second control signal is proportional to a phase difference between the first control signal and the second control signal.
PCT/JP2015/003821 2014-07-30 2015-07-29 Dc-dc converter WO2016017170A1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016152687A (en) * 2015-02-17 2016-08-22 株式会社日本自動車部品総合研究所 Dc/dc converter
JP2020028216A (en) * 2018-08-10 2020-02-20 シェンヂェン ヴイマックス ニュー エネルギー カンパニー リミテッドＳｈｅｎｚｈｅｎ ＶＭＡＸ Ｎｅｗ Ｅｎｅｒｇｙ Ｃｏ．，Ｌｔｄ． Phase shift control method for charging circuit
WO2024018813A1 (en) * 2022-07-18 2024-01-25 株式会社Soken Electric power conversion device and control program

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004282828A (en) * 2003-03-13 2004-10-07 Honda Motor Co Ltd Bidirectional dc-dc converter
WO2014103105A1 (en) * 2012-12-28 2014-07-03 パナソニック株式会社 Dc-to-dc converter

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5701283B2 (en) * 2012-12-25 2015-04-15 オムロンオートモーティブエレクトロニクス株式会社 Charger

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004282828A (en) * 2003-03-13 2004-10-07 Honda Motor Co Ltd Bidirectional dc-dc converter
WO2014103105A1 (en) * 2012-12-28 2014-07-03 パナソニック株式会社 Dc-to-dc converter

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016152687A (en) * 2015-02-17 2016-08-22 株式会社日本自動車部品総合研究所 Dc/dc converter
JP2020028216A (en) * 2018-08-10 2020-02-20 シェンヂェン ヴイマックス ニュー エネルギー カンパニー リミテッドＳｈｅｎｚｈｅｎ ＶＭＡＸ Ｎｅｗ Ｅｎｅｒｇｙ Ｃｏ．，Ｌｔｄ． Phase shift control method for charging circuit
WO2024018813A1 (en) * 2022-07-18 2024-01-25 株式会社Soken Electric power conversion device and control program

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