WO2008032362A1 - Dc/dc converter device - Google Patents

Abstract

A DC/DC converter device composed of a capacitor, switching transistors has a small-scale simple circuit structure and capable of increase the electric power to be converted. A DC/DC converter device comprises a series circuit of a capacitor (Ce) and an inductor (Lr) inserted between a low-voltage DC power supply (VL) and a high-voltage DC power supply (VH) and semiconductor switching elements (Sw1 to Sw4). A mode in which simultaneous conduction of the switches (Sw2, Sw3) and simultaneous conduction of the switches (Sw1, Sw4) are alternately switched by using as the drive frequency the resonance frequency at which the capacitor (Ce) and the inductor (Lr) series-resonate and the series circuit is connected parallel to the low-voltage DC power supply (VL) and a mode in which the series circuit is connected in series to the low-voltage DC power supply (VL) and this second series circuit is connected parallel to the high-voltage DC power supply (VH) are alternately switched thereby to increase the converted power for each switching.

Description

 Specification

 DCZDC converter device

 Technical field

 The present invention relates to a DCZDC converter device that converts a DC voltage into a DC voltage that is stepped up or stepped down.

 Background art

 [0002] A conventional DCZDC converter device includes m (m is an integer of 2 or more) number of parallel connected switched capacitor transformers, and each transformer includes a capacitor and a plurality of switching transistors. Composed. Each switched capacitor transformer has a switching signal that alternately switches between charging and discharging of the capacitor, and a clock signal whose phase is shifted by 2π / (rad) according to a predetermined input voltage. It is configured to be driven by a signal to be in a state (see, for example, Patent Document 1).

 [0003] Patent Document 1: Japanese Utility Model Publication No. 1 147685

 Disclosure of the invention

 Problems to be solved by the invention

 [0004] In such a conventional DCZDC converter device, the power is transferred by alternately switching the charge and discharge of the capacitor. However, if the amount of power to be transferred is increased, the power to increase the capacity of the capacitor and the switching of the switch element This will increase the frequency. The increase in capacitor capacity has the problem that the converter device becomes large. In addition, the increase in switching frequency requires a high-speed, high-precision control circuit element that supports high frequencies, and a gate drive circuit with high driving power is required to drive the switch element at high speed. There is a problem of high cost of the converter device.

 [0005] The present invention has been made to solve the above-described problems, and an object thereof is to obtain a DCZDC converter device capable of increasing the amount of power to be transferred with a small and simple circuit configuration. It is said.

 Means for solving the problem

[0006] A DCZDC converter device according to the present invention includes a low voltage side DC power supply and a high voltage side DC power supply. A capacitor and a plurality of semiconductor switching elements are provided between the power source and the capacitor, and charging and discharging of the capacitor are alternately switched by the switching operation of the semiconductor switching element.

Transfer energy between two power sources. Then, an inductor is inserted in a path section where the charging path and discharging path of the capacitor overlap, and the capacitor and the inductor are connected in series when the capacitor is charged and discharged.

 The invention's effect

 [0007] In such a DCZDC converter device, since the inductor is arranged in the charging path and discharging path of the capacitor, the resonance phenomenon between the capacitor and the inductor can be used by appropriately setting the switching frequency of the semiconductor switching element. It becomes possible. As a result, the amount of energy that can be transferred by one switching operation can be increased, and the amount of energy that can be transferred without increasing the capacitance of the capacitor or the switching frequency of the semiconductor switching element can be increased.

 Brief Description of Drawings

 FIG. 1 is a diagram showing a main circuit configuration of a converter device according to a first embodiment of the present invention.

 FIG. 2 is a diagram for explaining the operation of the converter device according to the first embodiment of the present invention.

 FIG. 3 is a diagram illustrating the effect of the converter device according to the first embodiment of the present invention using a comparative example.

 FIG. 4 is a diagram showing a main circuit configuration of a converter device according to another example of the first embodiment of the present invention.

 FIG. 5 is a diagram for explaining the operation of the converter device according to the second embodiment of the present invention.

 FIG. 6 shows a main circuit configuration of a converter device according to a third embodiment of the present invention.

 FIG. 7 is a diagram showing a main circuit configuration of a converter device according to another example of the third embodiment of the present invention.

 FIG. 8 shows a main circuit configuration of a converter device according to a fourth embodiment of the present invention.

 FIG. 9 is a diagram showing a main circuit configuration of a converter device according to another example of the fourth embodiment of the present invention.

 FIG. 10 is a diagram showing a main circuit configuration of a converter device according to a fifth embodiment of the present invention.

FIG. 11 is a diagram showing a main circuit configuration of a converter device according to a sixth embodiment of the present invention. FIG. 12 is a diagram showing a main circuit configuration of a converter device according to another example of the sixth embodiment of the present invention.

 FIG. 13 is a diagram for explaining the operation of the converter according to the sixth embodiment of the present invention.

 Explanation of symbols

 [0009] 1 SC type (Switched capacitor type) converter block

 la ~: Ld SC type converter block (SC type cell)

 2 Low voltage side DC power supply positive terminal

 2a Low voltage side DC power supply negative terminal (ground terminal)

 3 High voltage side DC power supply positive terminal

 3a High voltage side DC power supply negative terminal (ground terminal)

 10, 10a SC converter

 12 Setting frequency

 Ce, Cel to Ce3 capacitors

 Dil, Di2 First and second diodes

 Di3, Di4 First and second diodes

 Swl to Sw4 Switches as first to fourth semiconductor switching elements

 Swla, Sw2a Switches as first and second semiconductor switching elements

 Sw3a, Sw4a Switches as first and second semiconductor switching elements

 SwlOO, Sw201 to Sw203, Sw301 to Sw303, Sw401 to Sw403 Switch as a semiconductor switching element

 Lr, Lrl to Lr3 inductors

 BEST MODE FOR CARRYING OUT THE INVENTION

[0010] Embodiment 1.

 Hereinafter, a DCZDC converter device (hereinafter referred to as a converter device) according to Embodiment 1 of the present invention will be described with reference to the drawings.

 FIG. 1 is a diagram showing a main circuit configuration of a converter device according to Embodiment 1 of the present invention.

As shown in the figure, between the low voltage side (VL side) DC power supply and the high voltage side (VH side) DC power supply One SC type (switched capacitor type) converter block 1 is connected. Smoothing capacitors CL and CH for smoothing the voltage are connected between both terminals 2 and 2a of the low-voltage side DC power supply and between both terminals 3 and 3a of the high-voltage DC power supply. The negative terminal 2a and the negative terminal 3a of the high voltage side DC power source are grounded.

 Converter block 1 includes four MOSFETs (hereinafter referred to as switches) Swl to Sw4, capacitors Ce, and inductors Lr as semiconductor switching elements.

 The drain terminal of the switch Swl as the first semiconductor switching element is connected to the positive terminal 3 of the high voltage side DC power supply. In the switch Sw2 as the second semiconductor switching element, the drain terminal is connected to the source terminal of the switch Swl, and the source terminal is connected to the positive terminal 2 of the low-voltage side DC power supply. The source terminal of the switch Sw3 as the third semiconductor switching element is connected to the negative terminal 3a of the high voltage side DC power source and the negative terminal 2a of the low voltage side DC power source. In the switch Sw4 as the fourth semiconductor switching element, the source terminal is connected to the drain terminal of the switch Sw3, and the drain terminal is connected to the positive terminal 2 of the low-voltage DC power supply. The capacitor Ce and the inductor Lr are connected in series, and are connected between the connection point of the switches Swl and Sw2 and the connection point of the switches Sw3 and Sw4.

 [0012] Each switch Swl to Sw4 includes a gate drive signal generated by a control circuit unit (not shown).

 (Hereinafter referred to as a gate signal) is input, and an on-off operation is performed according to the voltage level of the gate signal. The voltage between terminals 2 and 2a of the low-voltage DC power supply is VL, and the voltage between terminals 3 and 3a of the high-voltage DC power supply is VH.

By switching between simultaneous conduction of switches Sw2 and Sw3 and simultaneous conduction of switches Swl and Sw4, when 2VL> VH, power is transferred from the low voltage side to the high voltage side, and when 2VL <VH. Shifts from the high voltage side to the low voltage side. The basic operation of the converter device in each case will be described below. As will be described later, the series resonance phenomenon of the inductor Lr and the capacitor _Ce is used. However, for the sake of convenience, the operation of the inductor Lr is ignored for the sake of convenience in order to explain the basic operation of power transfer.

[0013] When 2VL> VH, when switches Sw2 and Sw3 are on, switches Swl and Sw4 are off, and the current flows from smoothing capacitor CL (low voltage side positive terminal 2) to switch Sw2 to inductor Lr to capacitor It flows through the route from Ce to switch Sw3 to ground terminal 2a. As a result, the low voltage side The smoothing capacitor CL and the capacitor Ce are connected in parallel, and the capacitor Ce is charged to VL by the terminal voltage VL on the low voltage side. Next, when the switches Sw2 and Sw3 are turned off and the switches Swl and Sw4 are turned on, the current flows from the smoothing capacitor CL (low voltage side positive terminal 2) to the switch Sw4 to the capacitor Ce to the inductor Lr to the switch Swl to the smoothing capacitor. Flows from CH to ground terminal 3a, 2a. As a result, the smoothing capacitor CL and the capacitor Ce are connected in series, and the series body is connected in parallel with the smoothing capacitor CH. Since the smoothing capacitor and the capacitor Ce have a voltage VL, the voltage of the series body is 2VL. Since the terminal voltage VH on the high voltage side is smaller than 2VL, the energy shifts from the low voltage side to the high voltage side.

 [0014] In the case of 2VL and VH, when switches Swl and Sw4 are on, switches Sw2 and Sw3 are off, and the current flows from smoothing capacitor CH (high voltage side positive terminal 3) to switch Swl to inductor Lr to capacitor. Ce ~ Switch Sw4 ~ Smoothing capacitor CL ~ Ground terminal 2a, 3a flows. As a result, the smoothing capacitor CL and the capacitor Ce are connected in series, and the series body is connected in parallel with the smoothing capacitor CH. Since the voltages of the smoothing capacitors CL and CH are VL and VH, the capacitor Ce is charged with the voltage VH−VL. Next, when the switches Swl and Sw4 are turned off and the switches Sw2 and Sw3 are turned on, the current flows through a path from the capacitor Ce to the inductor Lr to the switch Sw2 to the smoothing capacitor CL to the switch Sw3. Thus, the smoothing capacitor CL and the capacitor Ce on the low voltage side are connected in parallel. Since the voltages of the smoothing capacitor CL and the capacitor Ce are VL and VH-VL, and VL and VH-VL, the energy is so that the voltage of the capacitor Ce becomes equal to the voltage VL between terminals on the low voltage side. Transition from the high voltage side to the low voltage side.

 [0015] Thus, in this converter device, VHZVL operates in such a way that power is transferred bidirectionally in the relationship of approximately two.

In either direction, switches Sw2 and Sw3 are simultaneously switched on and switches Swl and Sw4 are switched on alternately. The gate signals of switches Sw2 and Sw3 and the gate signals of switches Swl and Sw4 have the same shape. The switching of the switching operation switches between charging and discharging of the capacitor Ce to perform power transfer.However, since the inductor Lr is inserted in the section where the current path during charging and the current path during discharging overlap, Both current paths during discharge The 1S inductor Lr, capacitor Ce, and the resistance of the current flow path are connected in series. For this reason, the switching frequencies of the gate signals of the switches Sw2 and Sw3 and the gate signals of the switches Swl and Sw4 are made to coincide with the resonance frequency at which the inductor Lr and the capacitor Ce are in a series resonance state.

 [0016] The capacitance value of the capacitor Ce is Ce, the inductance value of the inductor Lr is Lr, the resistance of the path through which the current flows, that is, the on-resistance of the switch Sw2, Sw3 or the switch Swl, Sw4, the capacitor Ce, and the resistance of the inductor Lr If the sum of the components is R, the period T of the gate signal can be expressed by the following equation (1).

 [0017] [Equation 1]

[0018] As described above, when the inductor Lr and the capacitor Ce are in a series resonance state, the gate signals of the switches Swl to Sw4 and the voltage and current waveforms of the respective parts are shown in FIG. Fig. 2 (a) shows the case of 2VL> VH, and Fig. 2 (b) shows the case of 2VL> VH. Note that the current that flows from the positive terminal 2 of the low-voltage side DC power supply to the converter block 1 is IL, the current that flows from the converter block 1 to the positive terminal 3 of the high-voltage side DC power supply is IH, the current that flows to the capacitor Ce is Ice, and the capacitor The Ce voltage is Vce. The direction of the current and voltage arrows shown in Fig. 2 is positive.

 As shown in the figure, the switches Sw2, Sw3 and the switches Swl, Sw4 are switched on and off at the timing when the current Ice flowing in the capacitor Ce becomes zero, and the current Ic e flowing in the capacitor Ce is as shown in FIG. It becomes a continuous sinusoidal current. In addition, the current IL is a current waveform in which the current Ice is converted to an absolute value in either a positive or negative direction, and the current IH is a current waveform obtained by taking out only the ON periods of the switches IL and SW4 of the current IL.

In addition, the voltage Vce of the capacitor Ce is a voltage that oscillates in a sinusoidal shape centered on the voltage VL. The voltage shows a maximum value and a minimum value at the switching timing of each gate signal.

 As shown in the waveform of this voltage Vce, the voltage Vce of the capacitor Ce changes from VL + Δν to VL−Δν at the time of energy transfer. If the resonance phenomenon is not used, only the amount of charge of (2VL -VH) is transferred! On the other hand, in this embodiment, the energy transfer is larger than (2V L-VH). It becomes possible.

As described above, in this embodiment, since the series resonance phenomenon of the inductor Lr and the capacitor Ce is used, the current Ice flowing through the capacitor Ce can be made into a continuous sinusoidal current, and is used per switching. The amount of energy stored in the capacitor Ce can be increased. Therefore, it is possible to increase the amount of power transferred with a small and simple circuit configuration without increasing the capacitor capacity or increasing the switching frequency.

Next, using a converter device having the circuit configuration shown in FIG. 1 and having no inductor Lr as a comparative example, a characteristic comparison is made between the example in this embodiment (with inductor Lr) and the comparative example (without inductor). Figure 3 shows the results.

 Fig. 3 (a) shows the relationship between the capacitance value Ce of the capacitor Ce and the amount of energy transferred per switching from the low voltage side to the high voltage side. The calculation conditions are shown in Fig. 3 ( As shown in b), VL / VH = 144V / 284V, capacitor Ce charging and discharging path resistance R was 40mΩ, inductor Lr inductance value Lr was 1μΗ, and the maximum drive frequency was 100kHz.

 The driving frequency (gate signal frequency) of the embodiment (with inductor Lr) that uses the series resonance phenomenon of the inductor Lr and the capacitor Ce on the premise of switching when the current Ice flowing through the capacitor Ce becomes zero is Based on equation (1), the following force vj is used.

 [0022] [Equation 2]

[0023] 比較例 (インダクタ なし)の駆動周波数は、時定数に基づ!/、て求められ、以下のど ちら力 vj、さい方となる。

[0023] The drive frequency of the comparative example (without the inductor) is obtained based on the time constant! /, Which is the following force vj.

[0024] [Equation 3]

100 kHz

As shown in FIG. 3, the embodiment according to the present invention (with inductor Lr) transfers a large amount of power with a small capacitor capacity as compared with the comparative example (without inductor Lr).

 [0026] In the above embodiment, the inductor Lr is connected in series with the capacitor Ce and connected between the connection point of the switches Swl and Sw2 and the connection point of the switches Sw3 and Sw4. As shown, only the capacitor Ce is connected between the connection point of the switches Swl and Sw2 and the connection point of the switches Sw3 and Sw4, and the inductor Lr is connected to the low-voltage side positive terminal 2 and the switches Swl and Sw2. It may be inserted between points. In this case as well, since the inductor Lr is inserted in the section where the current path during charging and the current path during discharging overlap, the series resonance phenomenon of the inductor Lr and the capacitor Ce is used as in the above embodiment. And the same effect can be obtained.

 Embodiment 2.

 In the first embodiment, when the inductor Lr is manufactured using a small magnetic material for miniaturization and allowing some magnetic saturation, the inductor Lr depends on the flowing current level (transition power level). The inductance value changes. Figure 5 (a) shows the relationship between the amount of power transferred depending on the amount of current flowing through inductor Lr, and the inductance and current values of inductor Lr. As shown in the figure, the inductance value decreases as the electric energy (current amount) increases.

For this reason, in the second embodiment, the drive frequency is made variable, and the drive frequency is set to substantially match the resonance frequency that changes in accordance with the change in the inductance value. Here, as shown in Fig. 5 (b), the transition power region is divided into four, and the drive frequency is varied for each region. 11 is the resonance frequency that varies with the amount of power transferred, and 12 is the resonance frequency. This is the drive frequency (set frequency) that is switched and set accordingly. For example, a storage unit (not shown) is provided, and four types of clock signals having different frequencies are stored in the storage unit in advance, a DC current value on the low voltage side is detected, and a storage unit is detected according to the current value. Calls the clock signal and uses it to generate the gate signal for each switch Swl to Sw4.

 [0028] Thus, in this embodiment, the drive frequency is variable, and the drive frequency is set so as to substantially match the resonance frequency even when the resonance frequency changes. Therefore, a small magnetic body allows some magnetic saturation. Inductor Lr can be used, and the circuit configuration can be made inexpensive and small.

 [0029] Embodiment 3.

 In the first embodiment, the SC converter block 1 connected between the low voltage side (VL side) DC power source and the high voltage side (VH side) DC power source is connected to four switches Swl to Sw4 and capacitors. Force composed of Ce and inductor Lr In this third embodiment, converter block 1 is connected to diodes Dil, Di2 as first and second diodes, and switches (MOSFETs) as first and second semiconductor switching elements. Consists of Sw3a, Sw4a, capacitor Ce and inductor.

 FIG. 6 is a diagram showing a main circuit configuration of the converter device according to the third embodiment of the present invention.

 As shown in the figure, similar switches Sw3a and Sw4a are used instead of the switches Sw3 and Sw4 shown in the first embodiment. Further, instead of the switches Swl and Sw2 shown in the first embodiment, the force sword terminal is connected to the high-voltage side positive terminal 3 and the force sword terminal is connected to the anode terminal of the diode Dil. A diode Di2 whose anode terminal is connected to the switch Sw4a is used. Only the capacitor Ce is connected between the connection point of the diodes Dil and Di2 and the connection point of the switches Sw3a and Sw4a. The connection point of the diode Di2 and switch Sw4a is connected to the low-voltage side positive terminal 2 via the inductor Lr. Connect to.

 Note that the position of the inductor Lr only needs to be connected in series with the capacitor Ce when the capacitor Ce is charged and discharged, and FIG. 7 shows the case where the same position as in the first embodiment is acceptable.

Next, the operation will be described.

The switching frequency of the gate signal of switch Sw3a and the gate signal of switch Sw4a By switching the switch Sw3a and switch Sw4a alternately, the power is transferred from the low voltage side to the high voltage side when 2VL> VH. . Here, only the energy transfer from the low voltage side to the high voltage side is performed, and the same current and voltage waveforms shown in FIG. 2A of the first embodiment are obtained.

 The diode Dil is turned on by the electromotive voltage of the inductor Lr and the voltage of the capacitor Ce while the switch Sw4a is turned on and a current flows toward the high-voltage side positive terminal 3. The diode Di2 is switched by the switch Sw3a and the current flows from the low-voltage side positive terminal 2! /, While the voltage from the inductor Lr and the voltage difference between the low-voltage side positive terminal 2 and the capacitor Ce voltage Turns on. Both diodes Dil and Di2 are automatically turned off when the current direction is reversed.

 [0031] In this embodiment as well, since the series resonance phenomenon of the inductor Lr and the capacitor Ce is used, the current Ice flowing through the capacitor Ce can be made into a continuous sinusoidal current, and the capacitor Ce used per switching The amount of stored energy can be increased. For this reason, the amount of power transferred can be increased with a small and simple circuit configuration without increasing the capacitor capacity or increasing the switching frequency. In addition, since the plurality of semiconductor switching elements are two switches Sw3a and Sw4a, the gate drive circuit can be simplified.

 [0032] Embodiment 4.

 In the first embodiment, the SC converter block 1 connected between the low voltage side (VL side) DC power source and the high voltage side (VH side) DC power source is connected to four switches Swl to Sw4 and capacitors. Force composed of Ce and inductor Lr In this Embodiment 4, the converter block 1 is connected to the switches (MOSFETs) Swla, Sw2a as the first and second semiconductor switching elements, and the diode Di3 as the first and second diodes. , Di4, capacitor Ce and inductor.

 FIG. 8 shows a main circuit configuration of the converter device according to the fourth embodiment of the present invention.

As shown in the figure, similar switches Swla and Sw2a are used instead of the switches Swl and Sw2 shown in the first embodiment. Also, instead of the switches Sw3 and Sw4 shown in the first embodiment above, In addition, a diode Di3 whose anode terminal is connected to the ground terminals 2a and 3a and a diode Di4 whose anode terminal is connected to the force sword terminal of the diode Di3 and whose force sword terminal is connected to the switch Sw2a are used. Also, only the capacitor Ce is connected between the connection point of the diodes Di3 and Di4 and the connection point of the switches Swla and Sw2a, and the connection point of the diode Di4 and switch Sw2a is connected to the low-voltage side positive terminal 2 via the inductor Lr. Connecting.

 In this case as well, the position of the inductor Lr only needs to be connected in series with the capacitor Ce when the capacitor Ce is charged / discharged.

 Next, the operation will be described.

 By switching the switching frequency of the switch Swla gate signal and the switch Sw2a gate signal to the resonance frequency at which the inductor Lr and the capacitor Ce are in a series resonance state, and switching the switch Swla and the switch Sw2a alternately, 2VL is obtained. At VH, power is transferred from the high voltage side to the low voltage side. Here, only the energy transfer from the high voltage side to the low voltage side is performed, and the same current and voltage waveforms as shown in FIG. 2B of the first embodiment are obtained.

 The diode Di3 is turned on by the electromotive voltage of the inductor Lr and the voltage of the capacitor Ce while the switch Sw2a is turned on and the current flows from the capacitor Ce to the low-voltage side positive electrode terminal 2. The diode Di4 is connected to the voltage generated by the inductor Lr and the capacitor Ce voltage superimposed on the low-voltage side positive terminal 2 while the switch Swla is turned on and current flows from the high-voltage side positive terminal 3 to the low-voltage side. Turns on by voltage difference with voltage side terminal 3. Both diodes are automatically turned off when the current direction is reversed.

 [0034] In this embodiment as well, since the series resonance phenomenon of the inductor Lr and the capacitor Ce is used, the current Ice flowing in the capacitor Ce can be made into a continuous sinusoidal current, and the capacitor Ce used per switching The amount of stored energy can be increased. For this reason, the amount of power transferred can be increased with a small and simple circuit configuration without increasing the capacitor capacity or increasing the switching frequency. Also, since the plurality of semiconductor switching elements are two switches Swla and Sw2a, the gate drive circuit can be simplified.

[0035] Embodiment 5. In Embodiments 1 to 4 above, a force in which one SC converter block 1 is connected between the low voltage side (VL side) DC power source and the high voltage side (VH side) DC power source. Connect multiple SC converter blocks like this in parallel.

 FIG. 10 is a diagram showing a main circuit configuration of the converter device according to the fourth embodiment of the present invention.

 As shown in the figure, four SC cells la˜: Ld having the same SC-type converter block force as the converter block 1 shown in the first embodiment are connected to the low voltage side (VL side) DC power source and the high power source. Connect in parallel with the pressure side (VH side) DC power supply. As in the first embodiment, smoothing capacitors CL and CH for smoothing the voltage are connected between the low voltage side terminals 2 and 2a and between the high voltage side terminals 3 and 3a. Low voltage side negative terminal 2a and high voltage side negative terminal 3a are grounded.

[0036] Each SC cell la ~: The reference clock signal for driving Ld is shifted by 2 π Z4 (rad).

 In this way, by shifting the reference clock signal by 2π (4 (rad), the gate signals of the switches Swl to Sw4 constituting each la˜: Ld are also shifted by 2πΖ4 between the SC cells la˜ld. Also, the frequency of this clock signal is made to coincide with the resonance frequency at which the inductor Lr and the capacitor Ce are in series resonance, and the switching frequency of the switch in each SC cell la˜: Ld is made to coincide with the above resonance frequency. The operation in each SC cell la˜: Ld is the same as in the first embodiment.

 As a result, four times the amount of power can be transferred by four SC cells la˜: Ld, and the ripple currents of the smoothing capacitors CL and CH can be reduced. Since the capacitance values (size) of the smoothing capacitors CL and CH are determined depending on the magnitude of the ripple current value, the capacitance (size) of the smoothing capacitors CL and CH can be reduced by reducing the ripple current. .

[0037] In this embodiment, four SC cells la to: force using Ld

 The same operation can be performed by shifting the good reference clock signal by 2 π Ζη (rad) by (n). In this case, the larger the number of SC cells, the greater the effect of reducing the ripple current of the smoothing capacitors CL and CH, and the size of the smoothing capacitors CL and CH can be reduced.

Moreover, although each said SC cell la ~: Ld cord applied the said Embodiment 1, you may apply the said Embodiment 2 ~ 4. [0038] Embodiment 6.

 In Embodiments 1 to 5 described above, the power indicating the converter device in which VHZVL transfers power between the low-voltage side (VL side) DC power source and the high-voltage side (VH side) DC power source in an approximate relationship of 2 In the sixth embodiment, the case where the voltage ratio is 4 where VH is about 4VL will be described.

 FIG. 11 is a diagram showing a main circuit configuration of the converter device according to the sixth embodiment of the present invention.

 As shown in the figure, an SC converter device 10 is connected between a low voltage side (VL side) DC power source and a high voltage side (VH side) DC power source. Smoothing capacitors CL and CH for smoothing the voltage are connected between the low voltage side terminals 2 and 2a and between the high voltage side terminals 3 and 3a. The low voltage side negative terminal 2a and the high voltage side negative terminal 3a is grounded.

 As shown in the figure, converter device 10 includes four switches Swl00, Sw203, Sw303, Sw404, capacitor Ce3, and inductor Lr3 in the same configuration as converter block 1 of the first embodiment. Among these element configurations, the three switches Sw202, Sw302, Sw402, and the capacitor Ce2 are the same units as the unit composed of the three switches Sw203, Sw303, Sw404, the capacitor Ce3, and the inductor Lr3. And an inductor Lr2, three switches Sw201, Sw301, Sw401, a capacitor Cel, and an inductor Lrl.

 In FIG. 11, the source terminal of the switch Sw201 is connected to the positive terminal 2 on the low voltage side, the source terminal of the switch Sw202 is connected to the drain terminal of the switch Sw201, and the switch Sw203 is connected to the drain terminal of the switch Sw202. Similar to the later-described operation, it is possible to connect the source terminals of the switches Sw201 to Sw203 to the low-voltage side positive terminal 2 as in the converter device 10a shown in FIG.

 [0040] Each switch Swl00, Sw201 to 203, Sw301 to 303, and Sw401 to 403 receives a gate signal generated by a control circuit unit (not shown), and performs an on / off operation according to the voltage level of the gate signal.

Figure 13 shows the gate signal of each switch and the voltage and current waveforms of each part. VL, VH, IL, and IH are the voltages and currents for the same parts as in the first embodiment, and the currents flowing through the capacitors Cel to Ce3 and the voltages of the capacitors Cel to Ce3 are also shown. . Furthermore, the directions of the current and voltage arrows shown in FIG. 11 are positive.

 By alternately switching between simultaneous conduction of switches Sw201 to 203 and Sw301 to 303 and simultaneous conduction of switches Swl00 and Sw401 to 403, when 4VL> VH, power is transferred from the low voltage side to the high voltage side. In the case of 4VL to VH, power is transferred from the high voltage side to the low voltage side. The operation of the converter device in each case will be described below with reference to FIGS. 13 (a) and 13 (b).

 [0041] As shown in FIG. 13 (a), when 4VL> VH, the switches Swl00 and Sw401 to 403 are off when the switches Sw201 to 203 and Sw301 to 303 are on. Three series bodies (Cel, Lrl), (Ce2, Lr2), and (Ce3, Lr3) in which Ce3 and inductors Lrl to Lr3 are connected in series are parallel in parallel between both terminals 2 and 2a of the low-voltage DC power supply. Connected. As a result, the voltages of the capacitors Cel to Ce3 are charged to VL + Δν.

 Next, when the switches Sw201 to 203 and Sw301 to 303 are turned off and the switches Swl00 and Sw401 to 4003 are turned on, the three series-connected bodies (Cel, Lrl), (Ce2, Lr2), (Ce 3, Lr3) and smoothing capacitor CL are connected in series, and these series-connected composite series C L- (Cel, Lrl) (Ce2, Lr2) (Ce3, Lr3) are both terminals of the high-voltage side DC power supply 3 3a are connected in parallel. The energy shifts from the low voltage side to the high voltage side, and the capacitors Cel to Ce3 are discharged, and the voltage becomes VL−Δν.

 [0042] As shown in FIG. 13 (b), in the case of 4VL and VH, the switches Swl00 and Sw401 to 403 are off when the switches Sw201 to 203 and Sw301 to 303 are on. The bodies (Cel, Lrl), (Ce2, Lr2), and (Ce3, Lr3) are connected in parallel between both terminals 2 and 2a of the low-voltage DC power supply. The energy shifts from the high-voltage side force to the low-voltage side, and each capacitor Cel ~ Ce3 is discharged and the voltage becomes VL Δν.

 Next, when the switches Sw201 to 203 and Sw301 to 303 are turned off and the switches Swl00 and Sw401 to 4003 are turned on, the above three series bodies (Cel, Lrl), (Ce2, Lr2), (Ce3, Lr3) and The series capacitor CL (Cel, Lrl)-(Ce2, Lr2)-(Ce3, Lr3) is connected between the terminals 3 and 3a of the high-voltage side DC power supply. Connected in parallel. As a result, the voltages of the capacitors Cel to Ce3 are charged to VL + Δν.

[0043] Thus, the pair of capacitors Ce (Cel to Ce3) and the inductor Lr (Lrl to Lr3) are connected in series. Multiple connected series bodies (Ce, Lr) (in this case, 3) are provided, and these series bodies (Ce, Lr) are simultaneously connected in parallel between both terminals 2 and 2a of the low-voltage DC power supply. The first mode and the plurality of series bodies (Ce, Lr) are simultaneously connected in series to the low voltage side DC power supply (smoothing capacitor CL) and the series connected composite series body is connected to the high voltage side DC power supply. By alternately switching between the second mode connected in parallel between the terminals 3 and 3a, the charging and discharging of the plurality of capacitors Cel to Ce3 are simultaneously switched. The resistance of the charge / discharge path is almost negligible. In the first mode, the resonance period Ta in which each inductor Lr and each capacitor Ce is in a series resonance state has the inductance value of each Lr as Lr, If the capacitance value of each Ce is Ce, it can be expressed by the following formula (2).

[0044] [Equation 4]

· ' , ® Ta = 2 π

· ', ®

[0045] Further, in the second mode, the resonance period Tb in which each inductor Lr and each capacitor Ce is in a series resonance state is as follows. When the inductance value of each Lr is Lr and the capacitance value of each Ce is Ce, It can be expressed by the following formula (3).

[0046] [Equation 5]

[0047] From the above formulas (2) and (3), Ta = Tb, and the two types of gate signals used in the first and second modes are simply rectangular with a duty ratio of 50% as in the first embodiment. It becomes a pulse signal. Thus, even when voltage conversion is performed at a voltage ratio of 4, the series resonance phenomenon of the inductor Lr and the capacitor Ce can be used to increase the amount of energy stored in the capacitor Ce used per switching. Therefore, it is possible to increase the amount of power transferred with a small and simple circuit configuration without increasing the capacitor capacity or increasing the switching frequency.

[0048] Note that even if the circuit configuration shown in FIG. 1 of Embodiment 1 is provided in two stages, a converter device having a similar voltage ratio of 4 can be configured. In that case, install a smoothing capacitor between the first and second stages. In the configuration shown in FIGS. 11 and 12, only the smoothing capacitors CL and CH connected between the low voltage side terminals 2 and 2a and between the high voltage side terminals 3 and 3a are required.

 In addition, although a DC voltage conversion mode with a voltage ratio of 4 has been described, the above unit including a series body in which a capacitor Ce and an inductor Lr are connected in series and a plurality of switches is sufficient if the voltage ratio is an integer of 2 or more. By further increasing the power, it is possible to transfer power at a larger voltage ratio.

 In the first to sixth embodiments, the same effect can be obtained even if another semiconductor switching element such as a power IGBT using a MOSFET is used as the semiconductor switching element. Industrial applicability

[0050] The present invention can be applied to a booster circuit, a step-down circuit, or a step-up / step-down circuit that realizes energy transfer by switching charge / discharge of a capacitor by switching operation of a semiconductor switching element.

Claims

The scope of the claims  [1] A capacitor and a plurality of semiconductor switching elements are provided between the low-voltage side DC power supply and the high-voltage side DC power supply, and charging and discharging of the capacitor are alternately switched by the switching operation of the semiconductor switching element. For DC ZDC converter devices that transfer energy between the above two power supplies!  A DCZDC converter device, wherein an inductor is inserted in a path section where a charging path and a discharging path of the capacitor overlap, and the capacitor and the inductor are connected in series when the capacitor is charged and discharged. [2] The D according to claim 1, wherein a period of a drive signal for driving the plurality of semiconductor switching elements is substantially matched with a resonance period of the capacitor and the inductor. CZDC converter device. [3] The DCZDC converter device according to [2], wherein the period of the drive signal is variable in accordance with an inductance value of the inductor that varies depending on an amount of current flowing through the inductor.  [4] A cell that includes the capacitor, the inductor, and the plurality of semiconductor switching elements between the low-voltage side DC power source and the high-voltage side DC power source, and that transfers energy between the two power sources. , N (n is an integer of 2 or more) connected in parallel, and the drive signals for driving the semiconductor switching elements in each cell are shifted by 2 π Ζη between the cells. The DCZD C converter device according to any one of claims 1 to 3.  [5] The plurality of semiconductor switching elements are The first semiconductor switching element having one terminal connected to the positive terminal of the high-voltage side DC power supply, the other terminal of the first semiconductor switching element, and the positive terminal of the low-voltage side DC power supply A second semiconductor switching element to which a child is connected; a third semiconductor switching element having one terminal connected to the negative terminal of the high-voltage side DC power source and the negative terminal of the low-voltage side DC power source; A fourth semiconductor switching element having both terminals connected to the other terminal of the third semiconductor switching element and the positive terminal of the low-voltage side DC power source, A series body in which the capacitor and the inductor are connected in series is formed, and the connection point between the first and second semiconductor switching elements and the connection point between the third and fourth semiconductor switching elements are connected in series. Connect through the body,  The simultaneous conduction of the second and third semiconductor switching elements and the simultaneous conduction of the first and fourth semiconductor switching elements are alternately performed, and charging and discharging of the capacitor are alternately switched. The DCZDC converter device according to any one of claims 1 to 3. [6] The plurality of semiconductor switching elements are:  The first semiconductor switching element having one terminal connected to the positive terminal of the high-voltage side DC power supply, the other terminal of the first semiconductor switching element, and the positive terminal of the low-voltage side DC power supply A second semiconductor switching element to which a child is connected; a third semiconductor switching element having one terminal connected to the negative terminal of the high-voltage side DC power source and the negative terminal of the low-voltage side DC power source; A fourth semiconductor switching element having both terminals connected to the other terminal of the third semiconductor switching element and the terminal on the low-voltage side DC power supply side of the second semiconductor switching element,  The connection point between the first and second semiconductor switching elements and the connection point between the third and fourth semiconductor switching elements are connected via the capacitor,  The inductor is inserted between the positive terminal of the low-voltage DC power supply and the connection point between the second and fourth semiconductor switching elements,  The simultaneous conduction of the second and third semiconductor switching elements and the simultaneous conduction of the first and fourth semiconductor switching elements are alternately performed, and charging and discharging of the capacitor are alternately switched. The DCZDC converter device according to any one of claims 1 to 3. [7] A first diode in which the force sword terminal is connected to the positive terminal of the high-voltage side DC power source, a force sword terminal is connected to the anode terminal of the first diode, and the anode terminal is the low voltage side A second diode connected to a positive electrode terminal of a DC power supply, and the plurality of semiconductor switching elements include: A first semiconductor switching element having one terminal connected to the negative terminal of the high voltage side DC power supply and the negative terminal of the low voltage side DC power supply; the other terminal of the first semiconductor switching element; Both terminals are connected to the positive terminal of the voltage side DC power supply A second semiconductor switching element,  A series body in which the capacitor and the inductor are connected in series is formed, and the connection point between the first and second diodes and the connection point between the first and second semiconductor switching elements are connected to each other. Connect through  The first semiconductor switching element and the second semiconductor switching element are alternately turned on to alternately switch the charge and discharge of the capacitor, and energy is transferred from the low voltage side DC power source to the high voltage side DC power source. The DCZDC converter device according to any one of claims 1 to 3, wherein [8] A first diode in which the force sword terminal is connected to the positive terminal of the high-voltage side DC power source, a force sword terminal is connected to the anode terminal of the first diode, and the anode terminal is on the low voltage side A second diode connected to a positive electrode terminal of a DC power supply, and the plurality of semiconductor switching elements include:  A first semiconductor switching element having one terminal connected to the negative terminal of the high-voltage side DC power supply and the negative terminal of the low-voltage side DC power supply; the other terminal of the first semiconductor switching element; and the first terminal A second semiconductor switching element having both terminals connected to the anode terminal of the diode of  The connection point between the first and second diodes and the connection point between the first and second semiconductor switching elements are connected via the capacitor,  The inductor is inserted between the positive terminal of the low-voltage side DC power supply and the connection point between the second diode and the second semiconductor switching element,  The first semiconductor switching element and the second semiconductor switching element are alternately turned on to alternately switch the charge and discharge of the capacitor, and energy is transferred from the low voltage side DC power source to the high voltage side DC power source. The DCZDC converter device according to any one of claims 1 to 3, wherein [9] The anode terminal is connected to the negative terminal of the high-voltage side DC power supply and the negative terminal of the low-voltage side DC power supply, and the anode terminal is connected to the force sword terminal of the first diode. A force sword terminal and a second diode connected to the positive terminal of the low-voltage side DC power source, The plurality of semiconductor switching elements are:  The first semiconductor switching element having one terminal connected to the positive terminal of the high-voltage side DC power supply, the other terminal of the first semiconductor switching element, and the positive terminal of the low-voltage side DC power supply A second semiconductor switching element to which a child is connected, forming a series body in which the capacitor and the inductor are connected in series, and a connection point between the first and second diodes and the first And connecting the connection point between the second semiconductor switching elements through the series body,  The first semiconductor switching element and the second semiconductor switching element are alternately turned on to alternately switch charging and discharging of the capacitor, and energy is transferred from the high-voltage side DC power source to the low-voltage side DC power source. The DCZDC converter device according to any one of claims 1 to 3, wherein [10] The anode terminal is connected to the negative terminal of the high-voltage side DC power supply and the negative terminal of the low-voltage side DC power supply, and the anode terminal is connected to the force sword terminal of the first diode. A force sword terminal and a second diode connected to the positive terminal of the low-voltage side DC power source,  The plurality of semiconductor switching elements are:  One terminal is connected to both ends of the first semiconductor switching element connected to the positive terminal of the high-voltage side DC power source, the other terminal of the first semiconductor switching element, and the cathode terminal of the second diode. A connection point between the first and second diodes and a connection point between the first and second semiconductor switching elements via the capacitor. Connect  The inductor is inserted between the positive terminal of the low-voltage side DC power supply and the connection point between the second diode and the second semiconductor switching element,  The first semiconductor switching element and the second semiconductor switching element are alternately turned on to alternately switch charging and discharging of the capacitor, and energy is transferred from the high-voltage side DC power source to the low-voltage side DC power source. The DCZDC converter device according to any one of claims 1 to 3, wherein [11] Between the low voltage side DC power source and the high voltage side DC power source, the capacitor and the above A first mode in which a plurality of series bodies each having an inductor connected in series are provided, and the plurality of series bodies are simultaneously connected in parallel between both terminals of the low-voltage side DC power source by the switching operation of the plurality of semiconductor switching elements; And a second mode in which the plurality of series bodies are simultaneously connected in series to the low-voltage side DC power source and the series-connected composite series body is connected in parallel between both terminals of the high-voltage side DC power source. 4. The DCZDC converter device according to claim 1, wherein charging and discharging of the plurality of capacitors are simultaneously switched by alternately switching.