JP2013247814A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device in which the primary coil of a transformer is an input side and a first and a second load respectively are connected to a secondary coil via a rectification circuit and to a tertiary coil via a voltage adjustment switching circuit, and which can reduce a switching loss and a surge voltage as to the switching element of the voltage adjustment switching circuit.SOLUTION: A voltage adjustment switching circuit 40 includes diodes D31 and D32 and switching elements Q31 and Q32. A controller 50, after turning switching elements Q11 and Q14 off in order to break positive half-wave electrical conduction to a primary coil T11, turns the switching element Q31 off in order to break positive half-wave electrical conduction in a tertiary coil T13. Also, after turning switching elements Q12 and Q13 off in order to break negative half-wave electrical conduction to the primary coil T11, the controller 50 turns the switching element Q32 off in order to break negative half-wave electrical conduction in the tertiary coil T13.

Description

  The present invention relates to a power supply device.

  A high-voltage battery is mounted in a plug-in hybrid vehicle or an electric vehicle, and an on-vehicle charger for charging the high-voltage battery from an external commercial power source is used (for example, Patent Document 1).

  Specifically, the technique disclosed in Patent Document 1 can charge a main battery and an auxiliary battery having a lower voltage than the main battery with a system power supply. A transformer that connects the main battery side and the system power supply side in an electrically insulated state; a first bridge circuit that is connected between the main battery and the primary winding of the transformer and includes four switching elements; It is connected to the secondary winding and includes at least one second bridge circuit composed of four switching elements. In addition, a system power supply connection unit connected to the second bridge circuit, and an auxiliary battery provided so as to be connectable to the main battery side and system power supply connection unit side via a DC / DC converter are provided. . And while controlling each switching element of a 1st bridge circuit, each switching element of a 2nd bridge circuit, and the switching element of a DC / DC converter, it uses electric power of a main battery from the connection part for system power supplies of household appliances Control to output AC voltage and frequency AC voltage.

  With this configuration, the main battery and the auxiliary battery can be charged by the system power supply, and electric power for home appliances can be output using at least the main battery as a power source without providing a dedicated DC / AC inverter.

JP 2008-312395 A

  Incidentally, in an insulated switching power supply device (converter) in which an input and an output are electrically insulated by a transformer, it is desired to reduce switching loss and surge voltage.

  The object of the present invention is to connect the primary load of the transformer to the input side, the secondary load to the first load via a rectifier circuit, and the tertiary winding to the second load via a voltage adjustment switching circuit. Another object of the present invention is to provide a power supply device capable of reducing switching loss and surge voltage of a switching element of a voltage adjusting switching circuit in the power supply device.

  In the first aspect of the present invention, a transformer having a primary winding, a secondary winding, and a tertiary winding is connected to the primary winding of the transformer, and a positive half-wave is energized to the primary winding. A first primary winding side switching element for the first primary winding side switching element connected to the primary winding of the transformer, and a second primary winding side switching element for conducting negative half-wave energization to the primary winding; A first load connected to the secondary winding of the transformer via a rectifier circuit; a second load connected to the tertiary winding of the transformer via a voltage adjusting switching circuit; The primary winding side switching element and the second primary winding side switching element are controlled so that the primary winding of the transformer is energized and the secondary load of the transformer passes through the rectifier circuit to the first load side From the transformer's tertiary winding Control means for supplying power to the second load side via the voltage adjustment switching circuit, and the voltage adjustment switching circuit is connected to the positive terminal of the tertiary winding of the transformer via a diode. A first tertiary winding side switching element and a second tertiary winding side switching element connected to a negative terminal of the tertiary winding of the transformer via a diode, and the control means includes the primary winding The first tertiary winding to cut off the positive half-wave energization in the tertiary winding after turning off the first primary winding side switching element to cut off the positive half-wave energization to the wire A negative half-wave in the tertiary winding after turning off the second primary winding-side switching element to turn off the line-side switching element and cut off the negative half-wave energization to the primary winding. Block the power Turning off the second tertiary winding side switching elements so as to be summarized as.

  According to a second aspect of the present invention, in the power supply device according to the first aspect, the control means is configured to cause the first primary winding side switching element to energize the primary winding with a positive half-wave. To turn on the first tertiary winding side switching element so as to energize the positive half wave in the tertiary winding after turning on, and energize the negative half wave to the primary winding In summary, the second primary winding side switching element is turned on in order to cause the negative half wave to be energized in the tertiary winding after the second primary winding side switching element is turned on. To do.

  According to a third aspect of the present invention, in the power supply device according to the first or second aspect, the control means is configured to cause the first tertiary winding side to energize a positive half-wave in the tertiary winding. After turning on the switching element, the second tertiary winding side switching element is turned off to cut off the negative half-wave energization in the tertiary winding and the negative half-wave energization in the tertiary winding. The first tertiary winding side switching element is turned off to cut off the positive half-wave energization in the tertiary winding after the second tertiary winding side switching element is turned on to perform The gist.

  The invention according to claim 4 is the power supply device according to any one of claims 1 to 3, wherein the tertiary winding of the transformer has a center tap, and the center tap is grounded. And

  According to a fifth aspect of the present invention, in the power supply device according to any one of the first to third aspects, the positive terminal of the tertiary winding of the transformer is grounded via a diode and the tertiary winding of the transformer. The main point is that the negative terminal of the wire is grounded via a diode.

  According to the first, second, third, fourth, and fifth aspects of the present invention, the voltage adjusting switching circuit includes a first tertiary winding connected to the positive terminal of the tertiary winding of the transformer via the diode. The switching element and the second tertiary winding side switching element connected to the negative terminal of the tertiary winding of the transformer via a diode. Then, the control means turns off the first primary winding side switching element to cut off the positive half-wave energization to the primary winding, and then cuts off the positive half-wave energization in the tertiary winding. The first tertiary winding side switching element is turned off, and the second primary winding side switching element is turned off in order to cut off the negative half-wave energization to the primary winding. The second tertiary winding side switching element is turned off to cut off the half-wave energization.

  As a result, the switching loss is reduced by performing zero current switching when the first tertiary winding side switching element and the second tertiary winding side switching element are turned off in the voltage adjusting switching circuit connected to the tertiary winding of the transformer. And the surge voltage can be reduced.

  As a result, the transformer primary winding is the input side, the secondary load is connected to the first load via the rectifier circuit, and the secondary load is connected to the tertiary winding via the voltage adjustment switching circuit. With respect to the switching element of the voltage adjusting switching circuit, the switching loss can be reduced and the surge voltage can be reduced.

  According to the present invention, the primary winding of the transformer is connected to the input side, the first load is connected to the secondary winding via the rectifier circuit, and the second load is connected to the tertiary winding via the voltage adjusting switching circuit. The switching element of the voltage adjusting switching circuit in the power supply apparatus can reduce switching loss and surge voltage.

The circuit diagram of the power supply device in this embodiment. The time chart for demonstrating the effect | action of a power supply device. The circuit diagram for demonstrating the effect | action of a power supply device. The circuit diagram for demonstrating the effect | action of a power supply device. The circuit diagram for demonstrating the effect | action of a power supply device. The circuit diagram for demonstrating the effect | action of a power supply device. The circuit diagram for demonstrating the effect | action of a power supply device. The circuit diagram for demonstrating the effect | action of a power supply device. The circuit diagram of the power supply device of another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the power supply apparatus 10 in this embodiment is a vehicle-mounted power supply apparatus mounted on a plug-in hybrid vehicle or an electric vehicle.

  The power supply device 10 includes a transformer T1. The transformer T1 has a primary winding T11, a secondary winding T12, and a tertiary winding T13. The tertiary winding T13 has a center tap, and the center tap is grounded. The number of turns of the primary winding T11 of the transformer T1 is n1, the number of turns of the secondary winding T12 is n2, and the number of turns on the positive terminal side and the number of turns on the negative terminal side in the tertiary winding T13 are n3.

  An H bridge circuit 11 is connected to the primary winding T11 of the transformer T1. A rectifier circuit 12 is connected to the secondary winding T12 of the transformer T1. Furthermore, a voltage adjusting switching circuit 40 is connected to the tertiary winding T13 of the transformer T1.

  The H bridge circuit 11 includes switching elements Q11, Q12, Q13, and Q14. Switching elements Q11, Q12, Q13, and Q14 are constituted by MOSFETs, and parasitic diodes are connected in parallel to the MOSFETs. The source terminal of the switching element Q11 and the drain terminal of the switching element Q13 are connected, and the source terminal of the switching element Q12 and the drain terminal of the switching element Q14 are connected. The drain terminal of the switching element Q11 and the drain terminal of the switching element Q12 are connected, and the source terminal of the switching element Q13 and the source terminal of the switching element Q14 are connected.

  The drain terminals of the switching elements Q11 and Q12 and the source terminals of the switching elements Q13 and Q14 are connected to the capacitor C11. An input power supply is connected to the H bridge circuit 11 via a capacitor C11.

  The intermediate point of switching element Q11 and switching element Q13 is connected to one terminal of primary winding T11 of transformer T1, and the intermediate point of switching element Q12 and switching element Q14 is connected to the other terminal of primary winding T11 of transformer T1. It is connected.

In this way, the commercial power supply is connected to the primary winding T11 of the transformer T1 via the H bridge circuit 11.
The rectifier circuit 12 is a bridge rectifier circuit including four diodes D21, D22, D23, and D24. Diodes D21 and D22 are connected in series. The anode of the diode D21 and the cathode of the diode D22 are connected. Diodes D23 and D24 are connected in series. The anode of the diode D23 and the cathode of the diode D24 are connected. The cathodes of the diodes D21 and D23 are connected, and the anodes of the diodes D22 and D24 are connected.

  An intermediate point between the diode D21 and the diode D22 is connected to one terminal of the secondary winding T12 of the transformer T1, and an intermediate point between the diode D23 and the diode D24 is connected to the other terminal of the secondary winding T12 of the transformer T1. ing.

  The cathodes of the diodes D21 and D23 are connected to one electrode of the capacitor C21 via the coil L21, and the anodes of the diodes D22 and D24 are connected to the other electrode of the capacitor C21. A charging load R21 as a first load is connected to the capacitor C21. The charging load R21 is a high voltage battery. Thus, the charging load R21 is connected to the secondary winding T12 of the transformer T1 through the rectifier circuit 12. A travel motor is connected to the charging load R21 (high voltage battery) via an inverter.

  The voltage adjustment switching circuit 40 capable of performing the voltage adjustment operation includes diodes D31 and D32, switching elements Q31 and Q32, a freewheeling diode D33, a coil L31, and a capacitor C31. The switching elements Q31 and Q32 are constituted by MOSFETs, and parasitic diodes are connected in parallel to the MOSFETs.

  The anode of the diode D31 is connected to the positive terminal of the tertiary winding T13 of the transformer T1, and the drain terminal of the switching element Q31 is connected to the cathode of the diode D31. The anode of the diode D32 is connected to the negative terminal of the tertiary winding T13 of the transformer T1, and the drain terminal of the switching element Q32 is connected to the cathode of the diode D32. The source terminal of the switching element Q31 and the source terminal of the switching element Q32 are connected to one end of the coil L31. In this way, a center tap type full-wave rectifier circuit is configured.

  The other end of the coil L31 is connected to the positive electrode of the capacitor C31. The cathode of the return diode D33 is connected to one end of the coil L31, and the anode of the return diode D33 is connected to the negative electrode of the capacitor C31. The capacitor C31 is connected to an auxiliary machine load R33 as a second load through a filter constituted by a coil L32 and a capacitor C32. The auxiliary machine load R33 is an auxiliary battery, and an auxiliary machine (power management ECU or other auxiliary machine) is connected to the auxiliary battery.

  Thus, the auxiliary load R33 is connected to the tertiary winding T13 of the transformer T1 via the voltage adjustment switching circuit 40. Further, the transformer T1 has a secondary winding T12 to which a commercial power supply is connected on the primary winding T11 side, to which a high voltage battery is connected, and a tertiary winding T13 to which an auxiliary battery is connected.

The controller 50 senses the source voltage of switching element Q31, Q32 takes in the voltage (floating voltage) _{V F} applied across the freewheeling diode D33, the voltage applied from this potential between the gate and source of the switching element Q31, Q32 Adjust. The controller 50 controls the switching elements Q11, Q12, Q13, Q14 of the H bridge circuit 11 and the switching elements Q31, Q32 of the voltage adjustment switching circuit 40. Specifically, the terminal H1 of the controller 50 is connected to the gate terminal of the switching element Q11 via the gate resistor R11 and is connected to the gate terminal of the switching element Q14 via the gate resistor R14. The terminal H2 of the controller 50 is connected to the gate terminal of the switching element Q12 via the gate resistor R12 and is connected to the gate terminal of the switching element Q13 via the gate resistor R13. Furthermore, the terminal L1 of the controller 50 is connected to the gate terminal of the switching element Q31 via the gate resistor R31. Further, the terminal L2 of the controller 50 is connected to the gate terminal of the switching element Q32 via the gate resistor R32. The controller 50 can turn on and off the switching elements by adjusting the gate voltage of the switching elements corresponding to the respective terminals by sending pulse voltages to the respective terminals H1, H2, L1, and L2. It has become.

Next, the operation of the power supply device 10 will be described.
FIG. 2 is a time chart for explaining the operation of the switching elements Q11, Q12, Q13, Q14, Q31, and Q32 by the controller 50.

In the time chart, from the top, the level of the terminal H1 (the on / off state of the switching elements Q11, Q14), the level of the terminal H2 (the on / off state of the switching elements Q12, Q13), and the level of the terminal L1 (of the switching element Q31). ON / OFF state) and the level of the terminal L2 (the ON / OFF state of the switching element Q32). Further below it, the current _{I DS} flowing between the voltage _{V DS} and the drain-source between the drain and source of the switching element Q31, a current _{I DS} flowing between the voltage _{V DS} and the drain-source between the drain and source of the switching element Q32 , Current flowing through the freewheeling diode D33.

In FIG. 2, the on / off operation of the switching elements Q11 and Q14 rises at the timing t1, falls at the timing t4, rises again at the timing t9, and the period from t1 to t9 is one cycle. The on / off operation of the switching elements Q12 and Q13 rises at the timing t5 and falls at the timing t8. The on / off operation of the switching element Q31 rises at the timing t2 and falls at the timing t7. Further, the on / off operation of the switching element Q32 falls at the timing t3, rises at the timing t6, and falls at the timing t10. Switching elements Q11 and Q14 and switching elements Q12 and Q13 are PMW controlled and controlled at a fixed frequency. The duty ratio in the on / off control in the switching elements Q11 and Q14 is a ratio of the on period _TonH1 to one cycle, and this duty ratio is determined by the amount of electric power to the charging load R21. Similarly, the duty ratio in the on / off control in the switching elements Q12 and Q13 is a ratio of the on period _TonH2 to one cycle, and this duty ratio is determined by the amount of electric power to the charging load R21.

  Thus, the high voltage output at the secondary winding T12 of the transformer is feedback-controlled, and the auxiliary machine output at the tertiary winding T13 of the transformer is a voltage (21 to 21) which is higher than a desired voltage (about 13 to 14 volts). The auxiliary machine output at the transformer tertiary winding T13 adjusts the voltage in the voltage adjusting switching circuit 40. That is, since the auxiliary machine output at the transformer tertiary winding T13 becomes an indeterminate voltage depending on the high voltage output at the secondary winding T12, it is adjusted by the voltage adjusting switching circuit 40.

Regarding the operation of the voltage adjustment switching circuit 40, the switching elements Q11 and Q14 are turned on at the timing t1 in FIG. 2, but the switching element Q31 is turned on after the switching elements Q11 and Q14 are turned on. At this time, the on delay time t _dQ31 of the switching element Q31, that is, the off period (non-energization period) in the switching element Q31 is necessary in the switching element Q31 from the on period (conduction period) _TonH1 of the switching elements Q11 and Q14. This is a period obtained by subtracting a simple energization period _TonQ31 . The energization period _TonQ31 of the switching element Q31 is determined by feeding back the output voltage on the auxiliary machine side. Further, the switching element Q31 is continuously turned on after the timing t4, and is turned off at the timing t7 after the switching elements Q12 and Q13 are turned on at the timing t5.

Similarly, the switching elements Q12 and Q13 are turned on at the timing of t5 in FIG. 2, but the switching element Q32 is turned on after the switching elements Q12 and Q13 are turned on. In this case, delay time _{t DQ32} ON the switching element Q32 is, from the on-period (conduction _{period) T ONH2} of switching elements Q12, Q13, and a period obtained by subtracting the energization period _{T OnQ32} required in the switching element Q32. Further, the switching element Q32 is continuously turned on after the timing of t8, and is turned off at the timing of t10 after the switching elements Q11 and Q14 are turned on at the timing of t9.

  FIG. 3 shows an energization state in the period T1 from t1 to t2 in FIG. FIG. 4 shows the energization state of the period T2 from t2 to t3 and the period T3 from t3 to t4 in FIG. FIG. 5 shows the energization state during the period T4 from t4 to t5 in FIG. FIG. 6 shows an energization state in the period T5 from t5 to t6 in FIG. FIG. 7 shows the energization state of the period T6 from t6 to t7 and the period T7 from t7 to t8 in FIG. FIG. 8 shows the energization state during the period T8 from t8 to t9 in FIG.

  As shown in FIG. 3, switching elements Q11 and Q14 as the first primary winding side switching elements are connected to the primary winding T11 of the transformer T1, and energize the primary winding T11 with a positive half-wave. Is for. Further, as shown in FIG. 6, switching elements Q12 and Q13 as the second primary winding side switching elements are connected to the primary winding T11 of the transformer T1, and a negative half-wave energization is applied to the primary winding T11. Is for doing.

In the period T1 in FIG. 2, the switching elements Q11 and Q14 are turned on, the switching elements Q12 and Q13 are turned off, the switching element Q31 is turned off, and the switching element Q32 is turned on. In this period T1, as shown in FIG. 3, the alternating current from the commercial power source is converted into a direct current and inputted to the H bridge circuit 11, and the path of the switching element Q11 → the primary winding T11 of the transformer T1 → the switching element Q14. current _{I P} flows.

Thereby, an alternating current is induced in the secondary winding T12 of the transformer T1. In the rectifier circuit 12 a current _{I S} flows through a path of capacitor C21 → the diode D24 → second transformer T1 winding T12 → diode D21 → coil L21 → capacitor C21. In the voltage adjusting switching circuit 40, the current _ILV continuously flows through the path of the capacitor C31 → the freewheeling diode D33 → the coil L31 → the capacitor C31 in FIG.

In the period T1 in FIG. 2 shown in FIG. 3, the voltage _{V DS} between the drain and source of the switching element Q31 is, the tertiary winding to the voltage induced _{V t} and the switching elements of the transformer T1 Q31, Q32 source voltage The difference from V _F (V _t −V _F ). The voltage V _t induced in the tertiary winding of the transformer T1 is the input power supply voltage V _VH and the turns ratio N _T (= n3 / n1; n1 is the number of turns of the primary winding, n3 is the number of turns on the positive terminal side of the tertiary winding ). The current _{I DS} flowing between the drain and source of the switching element Q31 becomes "0". The voltage V _DS between the drain and source of the switching element Q32 is “0”, and the current I _DS flowing between the drain and source of the switching element Q32 is “0”.

In the period T2 in FIG. 2, the switching elements Q11 and Q14 are turned on, the switching elements Q12 and Q13 are turned off, the switching element Q31 is turned on, and the switching element Q32 is turned on. In this period T2, as shown in FIG. 4, the alternating current from the commercial power source is converted into a direct current and inputted to the H bridge circuit 11, and the path of the switching element Q11 → the primary winding T11 of the transformer T1 → the switching element Q14. current _{I P} flows.

Thereby, an alternating current is induced in the secondary winding T12 and the tertiary winding T13 of the transformer T1. In the rectifier circuit 12 a current _{I S} flows through a path of capacitor C21 → the diode D24 → second transformer T1 winding T12 → diode D21 → coil L21 → capacitor C21. In the voltage adjusting switching circuit 40, a current _ILV flows through a path of the tertiary winding T13 → the diode D31 → the switching element Q31 → the coil L31 → the capacitor C31.

In the period T2 of FIG. 2 shown in FIG. 4, the drain-source voltage V _DS of the switching element Q31 is “0”, the current I _DS flowing between the drain and source of the switching element Q31 is “I _LV ”, and switching The voltage V _DS between the drain and source of the element Q32 is “0”, and the current I _DS flowing between the drain and source of the switching element Q32 is “0”.

In period T3 in FIG. 2, switching elements Q11 and Q14 are turned on, switching elements Q12 and Q13 are turned off, switching element Q31 is turned on, and switching element Q32 is turned off. Also during this period T3, as shown in FIG. 4, the AC from the commercial power source is converted to DC and input to the H bridge circuit 11, and the path of the switching element Q11 → the primary winding T11 of the transformer T1 → the switching element Q14. current _{I P} flows.

Thereby, an alternating current is induced in the secondary winding T12 and the tertiary winding T13 of the transformer T1. In the rectifier circuit 12 a current _{I S} flows through a path of capacitor C21 → the diode D24 → second transformer T1 winding T12 → diode D21 → coil L21 → capacitor C21. In the voltage adjusting switching circuit 40, a current _ILV flows through a path of the tertiary winding T13 → the diode D31 → the switching element Q31 → the coil L31 → the capacitor C31.

In the period T3 of FIG. 2 shown in FIG. 4, the drain-source voltage V _DS of the switching element Q31 is “0”, the current I _DS flowing between the drain and source of the switching element Q31 is “I _LV ”, and switching The voltage V _DS between the drain and source of the element Q32 is “0”, and the current I _DS flowing between the drain and source of the switching element Q32 is “0”.

In the period T4 in FIG. 2, the switching elements Q11 and Q14 are turned off, the switching elements Q12 and Q13 are turned off, the switching element Q31 is turned on, and the switching element Q32 is turned off. In this period T5, as shown in FIG. 5, no current flows through the primary winding T11 of the transformer T1. In the rectifier circuit 12, a capacitor C21 → the diode D22 → the diode D21, and capacitor C21 → the diode D24 → via coil L21 through a diode D23 flows current _{I S} in a path back to the capacitor C21. In the voltage adjusting switching circuit 40, the current _ILV flows through the path of the capacitor C31 → the freewheeling diode D33 → the coil L31 → the capacitor C31.

In the period T4 of FIG. 2 shown in FIG. 5, the drain-source voltage V _DS of the switching element Q31 is “0”, and the current I _DS flowing between the drain and source of the switching element Q31 is “0”. Further, the drain-source voltage V _DS of the switching element Q32 is the difference (V _t −V _F ) between the transformer reset voltage V _t and the source voltage V _F of the switching elements Q31, Q32. The transformer reset voltage V _t is a _product of the input power supply voltage V _VH and the turn ratio N _T (= n3 / n1; n1 is the number of turns of the primary winding, and n3 is the number of turns on the negative terminal side of the tertiary winding). Current _{I DS} flowing between the drain and source of the switching element Q32 becomes "0".

  In this way, the controller 50 controls the switching elements Q11, Q12, Q13, and Q14, energizes the primary winding T11 of the transformer T1, and charges the charging load from the secondary winding T12 of the transformer T1 through the rectifier circuit 12. Power is supplied to the R21 side. Further, the controller 50 controls the switching elements Q11, Q12, Q13, and Q14 to supply power from the tertiary winding T13 of the transformer T1 to the auxiliary load R33 side through the voltage adjusting switching circuit 40.

In the period T5 in FIG. 2, the switching elements Q11 and Q14 are turned off, the switching elements Q12 and Q13 are turned on, the switching element Q31 is turned on, and the switching element Q32 is turned off. In this period T6, as shown in FIG. 6, the alternating current from the commercial power source is converted into a direct current and input to the H bridge circuit 11, and the path of the switching element Q12 → the primary winding T11 of the transformer T1 → the switching element Q13. current _{I P} flows.

Thereby, an alternating current is induced in the secondary winding T12 and the tertiary winding T13 of the transformer T1. In the rectifier circuit 12 a current _{I S} flows through a path of capacitor C21 → the diode D22 → second transformer T1 winding T12 → diode D23 → coil L21 → capacitor C21. In the voltage adjusting switching circuit 40, the current _ILV flows through the path of the capacitor C31 → the freewheeling diode D33 → the coil L31 → the capacitor C31.

In the period T5 of FIG. 2 shown in FIG. 6, the drain-source voltage V _DS of the switching element Q31 is “0”, and the current I _DS flowing between the drain and source of the switching element Q31 is “0”. Further, the voltage V _DS between the drain and source of the switching element Q32 is the difference between the voltage V _t induced in the tertiary winding of the transformer T1 and the voltage V _F of the source of the switching elements Q31 and Q32 (V _t −V _F ) The voltage V _t induced in the tertiary winding of the transformer T1 is the input power supply voltage V _VH and the turns ratio N _T (= n3 / n1; n1 is the number of turns of the primary winding, and n3 is the number of turns on the negative terminal side of the tertiary winding. ). Current _{I DS} flowing between the drain and source of the switching element Q32 becomes "0".

In the period T6 in FIG. 2, the switching elements Q11 and Q14 are turned off, the switching elements Q12 and Q13 are turned on, the switching element Q31 is turned on, and the switching element Q32 is turned on. In this period T6, as shown in FIG. 7, AC from the commercial power source is converted to DC and input to the H bridge circuit 11, and the current flows through the path of the switching element Q12 → the primary winding T11 of the transformer T1 → switching element Q13. I _P flows.

Thereby, an alternating current is induced in the secondary winding T12 and the tertiary winding T13 of the transformer T1. In the rectifier circuit 12 a current _{I S} flows through a path of capacitor C21 → the diode D22 → second transformer T1 winding T12 → diode D23 → coil L21 → capacitor C21. In the voltage adjusting switching circuit 40, the current _ILV flows through the path of the tertiary winding T13 of the transformer T1, the diode D32, the switching element Q32, the coil L31, and the capacitor C31.

In the period T6 of FIG. 2 shown in FIG. 7, the drain-source voltage V _DS of the switching element Q31 is “0”, and the current I _DS flowing between the drain and source of the switching element Q31 is “0”. Further, the drain-source voltage V _DS of the switching element Q32 is “0”, and the current I _DS flowing between the drain and source of the switching element Q32 is “I _LV ”.

In the period T7 in FIG. 2, the switching elements Q11 and Q14 are turned off, the switching elements Q12 and Q13 are turned on, the switching element Q31 is turned off, and the switching element Q32 is turned on. Also during this period T7, as shown in FIG. 7, AC from the commercial power source is converted to DC and input to the H-bridge circuit 11, and the path of the switching element Q12 → the primary winding T11 of the transformer T1 → the switching element Q13. current _{I P} flows.

Thereby, an alternating current is induced in the secondary winding T12 and the tertiary winding T13 of the transformer T1. In the rectifier circuit 12 a current _{I S} flows through a path of capacitor C21 → the diode D22 → second transformer T1 winding T12 → diode D23 → coil L21 → capacitor C21. In the voltage adjusting switching circuit 40, the current _ILV flows through the path of the tertiary winding T13 of the transformer T1, the diode D32, the switching element Q32, the coil L31, and the capacitor C31.

In the period T7 of FIG. 2 shown in FIG. 7, the drain-source voltage V _DS of the switching element Q31 is “0”, the current I _DS flowing between the drain and source of the switching element Q31 is “0”, and the switching element The voltage V _DS between the drain and source of Q32 is “0”, and the current I _DS flowing between the drain and source of the switching element Q32 is “I _LV ”.

In the period T8 in FIG. 2, the switching elements Q11 and Q14 are turned off, the switching elements Q12 and Q13 are turned off, the switching element Q31 is turned off, and the switching element Q32 is turned on. In this period T8, as shown in FIG. 8, no current flows through the primary winding T11 of the transformer T1. In the rectifier circuit 12, a capacitor C21 → the diode D22 → the diode D21, and capacitor C21 → the diode D24 → via coil L21 through a diode D23 flows current _{I S} in a path back to the capacitor C21. In the voltage adjusting switching circuit 40, a current _ILV flows through a path of the capacitor C31 → the freewheeling diode D33 → the coil L31 → the capacitor C31.

In the period T8 of Figure 2 shown in FIG. 8, the voltage _{V DS} between the drain and source of the switching element Q31 is, difference between the voltage _{V F} of the source of the transformer reset voltage _{V t} and the switching elements Q31, Q32 _{(V t} −V _F ). The transformer reset voltage V _t is a multiplication value of the input power supply voltage V _VH and the turn ratio N _T (= n3 / n1; n1 is the number of turns of the primary winding, and n3 is the number of turns of the tertiary winding on the positive terminal side). Current _{I DS} flowing between the drain and source of the switching element Q31 becomes "0". The voltage V _DS between the drain and source of the switching element Q32 is “0”, and the current I _DS flowing between the drain and source of the switching element Q32 is “0”.

  In this way, the controller 50 controls the switching elements Q11, Q12, Q13, and Q14, energizes the primary winding T11 of the transformer T1, and charges the charging load from the secondary winding T12 of the transformer T1 through the rectifier circuit 12. Power is supplied to the R21 side. Further, the controller 50 controls the switching elements Q11, Q12, Q13, and Q14 to supply power from the tertiary winding T13 of the transformer T1 to the auxiliary load R33 side through the voltage adjusting switching circuit 40.

At this time, the controller 50 turns off the first primary winding side switching elements Q11 and Q14 to cut off the positive half-wave energization to the primary winding T11 at t7 after the timing t4 in FIG. At the timing, the first tertiary winding side switching element Q31 is turned off to cut off the positive half-wave energization in the tertiary winding T13. The timing t7 in Fig. 2 is a current I _DS flowing between the drain and source of the switching element Q31 is "0", the current I _DS is the switching element Q31 is turned off when a "0". Further, the controller 50 turns off the second primary winding side switching elements Q12 and Q13 to cut off the negative half-wave energization to the primary winding T11, and the timing t10 after the timing t8 in FIG. Then, the second tertiary winding side switching element Q32 is turned off to cut off the negative half-wave energization in the tertiary winding T13. The timing t10 in FIG. 2 is a current _{I DS} flowing between the drain and source of the switching element Q32 is "0", the current _{I DS} is the switching element Q32 is turned off when a "0".

  As a result, zero current switching is performed when the first tertiary winding side switching element Q31 and the second tertiary winding side switching element Q32 in the voltage adjusting switching circuit 40 connected to the tertiary winding T13 of the transformer T1 are turned off. The switching loss can be reduced and the surge voltage can be reduced.

  Further, the controller 50 turns on the first primary winding side switching elements Q11 and Q14 to energize the primary winding T11 at the timing t1 in FIG. 2 and then turns on the t2 in FIG. The first tertiary winding-side switching element Q31 is turned on so that the positive half-wave energization is performed in the tertiary winding T13 at the timing. Further, the controller 50 turns on the second primary winding side switching elements Q12 and Q13 so as to energize the negative half-wave to the primary winding T11 at the timing of t5 in FIG. At this time, the second tertiary winding side switching element Q32 is turned on so that the negative half-wave is energized in the tertiary winding T13.

  Further, the controller 50 turns on the first tertiary winding side switching element Q31 to energize the positive half-wave in the tertiary winding T13 at the timing t2 in FIG. 2 and then the timing at t3 in FIG. Then, the second tertiary winding side switching element Q32 is turned off to cut off the negative half-wave energization in the tertiary winding T13. Further, the controller 50 turns on the second tertiary winding side switching element Q32 so as to energize the negative half-wave in the tertiary winding T13 at the timing t6 in FIG. 2, and then the timing at t7 in FIG. Then, the first tertiary winding side switching element Q31 is turned off to cut off the positive half-wave energization in the tertiary winding T13.

According to the above embodiment, the following effects can be obtained.
(1) The voltage adjusting switching circuit 40 includes the first tertiary winding side switching element Q31 connected to the positive terminal of the tertiary winding T13 of the transformer T1 via the diode D31 and the tertiary winding T13 of the transformer T1. It has the 2nd tertiary winding side switching element Q32 connected to the negative terminal via the diode D32. The controller 50 as the control means turns off the first primary winding side switching elements Q11 and Q14 to cut off the positive half-wave energization to the primary winding T11, and then the positive half-wave in the tertiary winding T13. The first tertiary winding side switching element Q31 is turned off to cut off the energization of the wave. Further, the controller 50 turns off the second primary winding side switching elements Q12 and Q13 to cut off the negative half-wave energization to the primary winding T11, and then the negative half-wave in the tertiary winding T13. The second tertiary winding side switching element Q32 is turned off to cut off the energization. Therefore, switching loss can be reduced and surge voltage can be reduced by performing zero current switching when the first tertiary winding side switching element Q31 and the second tertiary winding side switching element Q32 are turned off. .

  As a result, it becomes as follows. The primary winding T11 of the transformer T1 is connected to the input side, the secondary winding T12 is connected to the charging load R21 via the rectifier circuit 12, and the tertiary winding T13 is connected to the auxiliary load R33 via the voltage adjusting switching circuit 40. Yes. The switching elements Q31 and Q32 of the voltage adjusting switching circuit 40 in this power supply apparatus can reduce switching loss and surge voltage.

(2) Since the tertiary winding T13 of the transformer T1 has a center tap, and the center tap is grounded, the configuration can be simplified.
The embodiment is not limited to the above, and may be embodied as follows, for example.

  The circuit configuration of the voltage adjustment switching circuit 40 may be as shown in FIG. That is, the positive terminal of the transformer tertiary winding T13 is grounded via the freewheeling diode D33, and the negative terminal of the transformer tertiary winding T13 is grounded via the diode D34 to form a bridge-type full-wave rectifier circuit. May be.

  -Although MOSFET was used as a switching element, you may use an insulated gate bipolar transistor (IGBT) as a switching element. In the case of using the IGBT, a diode is connected between the collector and the emitter in reverse parallel with the cathode corresponding to the collector and the anode corresponding to the emitter.

  DESCRIPTION OF SYMBOLS 10 ... Power supply device, 12 ... Rectifier circuit, 40 ... Voltage adjustment switching circuit, 50 ... Controller, D31 ... Diode, D32 ... Diode, Q11 ... Switching element, Q12 ... Switching element, Q13 ... Switching element, Q14 ... Switching element, Q31: switching element, Q32: switching element, R21: charging load, R33: auxiliary load, T1: transformer, T11: primary winding, T12: secondary winding, T13: tertiary winding.

Claims (5)

A transformer having a primary winding, a secondary winding and a tertiary winding;
A first primary winding side switching element connected to the primary winding of the transformer and energizing a positive half-wave to the primary winding;
A second primary winding-side switching element connected to the primary winding of the transformer and configured to energize a negative half-wave to the primary winding;
A first load connected to the secondary winding of the transformer via a rectifier circuit;
A second load connected to the tertiary winding of the transformer via a voltage adjusting switching circuit;
The first primary winding side switching element and the second primary winding side switching element are controlled so that the primary winding of the transformer is energized and the secondary winding of the transformer passes through the rectifier circuit to Control means for supplying power to the first load side and supplying power to the second load side from the tertiary winding of the transformer via the voltage adjusting switching circuit;
With
The switching circuit for voltage regulation includes a first tertiary winding side switching element connected to a positive terminal of a tertiary winding of the transformer via a diode and a diode to a negative terminal of the tertiary winding of the transformer. A second tertiary winding side switching element connected to each other,
The control means cuts off the positive half-wave energization in the tertiary winding after turning off the first primary winding-side switching element to cut off the positive half-wave energization to the primary winding. The first tertiary winding side switching element is turned off to make the first winding turn off, and the third primary winding side switching element is turned off to cut off the negative half-wave energization to the primary winding. A power supply device characterized in that the second tertiary winding side switching element is turned off in order to cut off the negative half-wave energization in the winding.   The control means performs energization of the positive half wave in the tertiary winding after turning on the first primary winding side switching element to energize the primary winding in the positive half wave. The first tertiary winding side switching element is turned on as much as possible, and the secondary primary winding side switching element is turned on so as to energize the negative half wave to the primary winding. 2. The power supply device according to claim 1, wherein the second tertiary winding side switching element is turned on so as to energize a negative half-wave in the winding.   The control means cuts off the negative half-wave energization in the tertiary winding after turning on the first tertiary winding-side switching element so as to energize the positive half-wave in the tertiary winding. In order to turn off the second tertiary winding side switching element, and to turn on the second tertiary winding side switching element to turn on the negative half-wave in the tertiary winding, the tertiary 3. The power supply device according to claim 1, wherein the first tertiary winding side switching element is turned off to cut off the positive half-wave energization in the winding.   The power supply device according to any one of claims 1 to 3, wherein the tertiary winding of the transformer has a center tap, and the center tap is grounded.   The positive terminal of the tertiary winding of the transformer is grounded via a diode, and the negative terminal of the tertiary winding of the transformer is grounded via a diode. The power supply device according to claim 1.