WO2021039424A1 - Power supply circuit - Google Patents

Power supply circuit Download PDF

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Publication number
WO2021039424A1
WO2021039424A1 PCT/JP2020/030794 JP2020030794W WO2021039424A1 WO 2021039424 A1 WO2021039424 A1 WO 2021039424A1 JP 2020030794 W JP2020030794 W JP 2020030794W WO 2021039424 A1 WO2021039424 A1 WO 2021039424A1
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Prior art keywords
voltage
circuit
switch
diode bridge
bridge
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PCT/JP2020/030794
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French (fr)
Japanese (ja)
Inventor
隆芳 西山
太佳雄 大須賀
直人 木下
祥平 宮田
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株式会社村田製作所
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Publication of WO2021039424A1 publication Critical patent/WO2021039424A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode

Definitions

  • the present invention relates to a power supply circuit.
  • the present invention has been made in view of the above reasons, and provides a power supply circuit capable of reducing stress applied to elements constituting a circuit connected to the subsequent stage of a diode bridge when a disturbance is superimposed on an input voltage.
  • the purpose is to reduce stress applied to elements constituting a circuit connected to the subsequent stage of a diode bridge when a disturbance is superimposed on an input voltage.
  • the power supply circuit A diode bridge that rectifies the voltage and A plurality of first switches connected in parallel to each of the diodes constituting the diode bridge, A polarity detection circuit that detects the polarity of the voltage and A bridge control circuit that controls an open / closed state of the first switch based on the polarity of the voltage detected by the polarity detection circuit and the voltage between the output ends of the diode bridge is provided.
  • the bridge control circuit keeps at least one of the first switches open in the path through which the current flows until the voltage between the output ends of the diode bridge changes within a preset voltage range. maintain.
  • the power supply circuit is A second switch connected in series between the diode bridge and a subsequent circuit connected to the subsequent stage of the diode bridge, A voltage detector that detects the voltage between the output ends of the diode bridge, It may further include a switch control unit that keeps the second switch in an open state until the voltage detected by the voltage detection unit changes within a preset voltage range. ..
  • the power supply circuit is The polarity detection circuit detects the polarity of the voltage and outputs a voltage signal corresponding to the detected polarity.
  • the voltage signal is input to the bridge control circuit, and the voltage signal is detected by the polarity detection circuit.
  • the first switch may be opened and closed, and when power is not supplied from the subsequent circuit, the first switch may be maintained in an open state.
  • the power supply circuit according to the present invention is The subsequent circuit has a booster circuit that boosts the voltage to a voltage higher than the output voltage of the diode bridge.
  • the bridge control circuit When the bridge control circuit is connected to the output end of the booster circuit and the voltage signal is input to the bridge control circuit, the voltage output from the booster circuit is sent to the first switch in response to the voltage signal. It may be applied.
  • the subsequent circuit connected to the subsequent stage of the diode bridge may be a power conversion circuit that converts a DC voltage input from the diode bridge.
  • the bridge control circuit maintains the first switch in the open state until the voltage between the output ends of the diode bridge changes within a preset voltage range.
  • the disturbance superimposed on the input voltage is reduced by the diode bridge, so that the stress applied to the elements constituting the circuit connected to the subsequent stage of the diode bridge can be reduced.
  • the power supply circuit includes a diode bridge that rectifies the AC voltage applied to the input terminal, a first switch connected in parallel to each of the diodes constituting the diode bridge, and a voltage applied to the input terminal.
  • a polarity detection circuit for detecting the polarity of the first switch and a bridge control circuit for controlling the open / closed state of the first switch are provided. Then, in the bridge control circuit, after the AC voltage is applied to the input end of the diode bridge, the voltage between the output ends of the diode bridge changes within a preset voltage range for a preset period. 1 Keep the switch open.
  • the bridge control circuit switches the first switches SW1 and SW2 based on the polarity of the polarity detection circuit, assuming that the disturbance has subsided.
  • the closed state or the first switches SW3 and SW4 are closed.
  • the polarity of the voltage applied between the diode bridge DB1 having the input ends tei1 and tei2 and the output ends teoh and teol and the input ends tie1 and tei2 is determined.
  • Supply DC power is connected between the output ends teoh2 and teol2 of the power conversion circuit 2.
  • the power supply circuit includes switches SW1, SW2, SW3, SW4, and a bridge control circuit 12. Further, the power supply circuit detects the voltage between the switch 14 connected between the diode bridge DB1 and the power conversion circuit 2, the switch control unit 15 that controls the switch 14, and the output ends teah and teol of the diode bridge DB1.
  • the voltage detection unit 131 is provided.
  • An AC power supply AC is connected between the input ends tei1 and tei2 of the diode bridge DB1. Further, a power conversion circuit 2 is connected to the subsequent stage of the diode bridge DB1.
  • the diode bridge DB1 is composed of four diodes D11, D12, D13 and D14. In the diode D11, the anode is connected to the input end tei1 and the cathode is connected to the input end tei2. In the diode D12, the anode is connected to the output end teol and the cathode is connected to the input end tei2.
  • the anode is connected to the input end tei2 and the cathode is connected to the output end teoh.
  • the anode is connected to the output end teol and the cathode is connected to the input end tei1.
  • the switches SW1, SW2, SW3, and SW4 are first switches having, for example, FETs and bipolar transistors and connected in parallel to each of the four diodes D11, D12, D13, and D14.
  • An N-channel FET may be used for the switches SW1 and SW3 on the high side. Since the N-channel FET requires a boosted voltage to be in the closed state, it is unlikely that the N-channel FET will be closed due to a malfunction, and disturbance can be suppressed more reliably.
  • the polarity detection circuit 11 includes, for example, as shown in FIG. 2, a comparator 111 including, for example, an operational amplifier, and an inverting circuit 112 including, for example, an inverting amplifier circuit.
  • the comparator 111 compares the potentials of the connection point a on one output end side of the AC power supply AC and the connection point b on the other output end side, and the potential of the connection point a is higher than the potential of the connection point b. At that time, a preset H level voltage signal is output.
  • the H level is set to a specified voltage equal to or higher than the turn-on voltage of the switches SW11, SW12, SW13, and SW14.
  • the inverting circuit 112 when the H level voltage signal is input, the inverting circuit 112 performs a conversion that inverts the logic and outputs a preset L level voltage signal.
  • the L level is set to a specified voltage lower than the turn-on voltage of the switches SW11, SW12, SW13, and SW14.
  • the comparator 111 outputs the above-mentioned L level voltage signal when the potential of the connection point a is lower than the potential of the connection point b.
  • the inverting circuit 112 performs a conversion that inverts the logic and outputs the above-mentioned H level voltage signal.
  • the power conversion circuit 2 is a flyback type DC-DC converter, and includes a transformer TR1, switching elements Q21 and Q22, a drive circuit 21, capacitors C21, C22, C23, and a diode D2. It is a post-stage circuit having.
  • the transformer TR1 has a primary coil L11 and L12 and a secondary coil L2 that are inductively coupled to each other. One end of the coil L11 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the switching element Q21.
  • the switching element Q21 is an FET and is connected between the other end of the coil L11 of the transformer TR1 and the switch 14.
  • the drain of the switching element Q21 is connected to the other end of the coil L11 of the transformer TR1, and the source of the switching element Q21 is connected to the switch 14.
  • the switching element Q22 is connected between the other end of the coil L2 of the transformer TR1 and the output end teol2 on the low potential side of the power conversion circuit 2.
  • the drain of the switching element Q22 is connected to the other end of the coil L2 of the transformer TR1, and the source of the switching element Q22 is connected to the output end teol2.
  • the drive circuit 21 is connected to the output terminal teh on the high potential side of the diode bridge DB1, receives DC power from the diode bridge DB1, and outputs a control signal to the gates of the switching elements Q21 and Q22.
  • the switching elements Q21 and Q22 are turned on and off by the control signal input from the drive circuit 21.
  • the capacitor C21 is for smoothing the DC voltage output from the diode bridge DB1, and is connected between the output end teah on the high potential side of the diode bridge DB1 and the switch 14.
  • the capacitor C22 is for stabilizing the DC voltage output from the power conversion circuit 2, and is connected between the output ends teoh2 and teol2 of the power conversion circuit 2.
  • the anode is connected to the other end of the coil L12 of the transformer TR1, and the cathode is connected to the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12.
  • the capacitor C23 is for stabilizing the voltage output to each of the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12, which will be described later, and is the cathode of the diode D2 and the output end teah on the high potential side of the diode bridge DB1.
  • the booster circuit is composed of the coils L11 and L12, the switching element Q21, and the diode D2.
  • each switch SW11, SW12, SW13, SW14 of the bridge control circuit 12 is boosted to a voltage higher than the output voltage of the diode bridge DB1, in other words, a DC voltage is superimposed on the output voltage of the diode bridge DB1. Apply the voltage.
  • the bridge control circuit 12 controls the open / closed state of the switches SW1, SW2, SW3, and SW4 based on the polarity of the voltage detected by the polarity detection circuit 11 and the voltage between the output ends of the diode bridge DB1.
  • the bridge control circuit 12 has switches SW11, SW12, SW13, and SW14.
  • the switch SW11 is connected between the output terminal te111 of the polarity detection circuit 11 and the switch SW1.
  • the switch SW12 is connected between the output terminal te112 of the polarity detection circuit 11 and the switch SW2.
  • the switch SW13 is connected between the output terminal te113 of the polarity detection circuit 11 and the switch SW3.
  • the switch SW14 is connected between the output terminal te114 of the polarity detection circuit 11 and the switch SW4. Then, in a state where power is not supplied to the power conversion circuit 2, the switches SW1, SW2, SW3, and SW4 are maintained in an open state regardless of the level of the voltage signal input from the polarity detection circuit 11.
  • the switch 14 is a second switch arranged in a path through which a current flows from the diode bridge DB1 to the power conversion circuit 2.
  • the switch 14 switches between a state in which power is being supplied from the diode bridge DB1 to the power conversion circuit 2 and a state in which the power supply from the diode bridge DB1 to the power conversion circuit 2 is cut off.
  • This switch 14 is connected between the output terminal electricity on the low potential side of the diode bridge DB1 and the power conversion circuit 2 connected to the subsequent stage of the diode bridge DB1.
  • the switch control unit 15 is composed of, for example, dedicated hardware, and the voltage between the output terminals teah and steel of the diode bridge DB1 within a preset period detected by the voltage detection unit 131 is a preset voltage range.
  • the open / closed state of the switch 14 is controlled based on whether or not the transition is within the range.
  • the length of the preset period is set to, for example, 1 msec.
  • the voltage range is set based on, for example, the IEEE standard, and is set in a range of 30 V or more and 57 V or less.
  • the switch control unit 15 outputs an enable signal to the switch 14 to switch when the voltage between the output terminal teah and teol of the diode bridge DB1 is within the preset voltage range within a preset period. 14 is closed.
  • the switch control unit 15 is in a state in which the disturbance superimposed on the voltage applied to the input terminal of the diode bridge has subsided (the voltage between the output terminals teah and steel of the diode bridge DB1 is within a preset voltage range. It is assumed that the enable signal is output to the switch 14 and the switch 14 is closed as a state in which the state has changed for a preset period.
  • the current flowing out from the output end on the connection point a side of the AC power supply AC flows into the input end tee1 of the diode bridge DB1 and then bypasses the diode D11 in the closed state. It flows out from the output end teah on the high potential side of the diode bridge DB1 via the switch SW1.
  • the current flowing out from the output terminal teah on the high potential side of the diode bridge DB1 flows into the output terminal teal on the low potential side of the diode bridge DB1 via the power conversion circuit 2.
  • the current flowing into the output end teol on the low potential side of the diode bridge DB1 returns to the AC power supply AC via the closed switch SW2 and the input end tei2 that bypass the diode D12.
  • the current flowing out from the output end on the connection point b side of the AC power supply AC flows into the input end tee2 of the diode bridge DB1 and then bypasses the diode D13 in the closed state. It flows out from the output terminal teh on the high potential side of the diode bridge DB1 via the switch SW3.
  • the current flowing out from the output terminal teah on the high potential side of the diode bridge DB1 flows into the output terminal teal on the low potential side of the diode bridge DB1 via the power conversion circuit 2.
  • the current flowing into the output end teol on the low potential side of the diode bridge DB1 returns to the AC power supply AC via the closed switch SW4 that bypasses the diode D14 and the input end tee1.
  • the switch control unit 15 acquires the history of the voltage between the output terminals teah and teol of the diode bridge DB1 within a preset period detected by the voltage detection unit 131 (step S101).
  • the switch control unit 15 based on the acquired history of the voltage between the output terminal teoh and teol of the diode bridge DB1, all the voltages between the output terminal teoh and teol within a preset period are the lower limit values.
  • step S102 It is determined whether or not the voltage is within the voltage range of Vminth or more and the voltage upper limit value Vmaxth or less.
  • the preset period is set to, for example, 1 msec as described above.
  • the voltage lower limit value Vminth and the voltage upper limit value Vmaxth are set to, for example, 30V and 57V, respectively, as described above.
  • Step S102 No).
  • the switch control unit 15 executes the process of step S101 again.
  • the switch 14 since the switch 14 is maintained in the open state, DC power is not supplied from the diode bridge DB1 to the power conversion circuit 2, and the power conversion circuit 2 to the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12 respectively. No voltage is applied.
  • the switches SW1, SW2, SW3, and SW4 are maintained in the open state regardless of the voltage signal output from the polarity detection circuit 11. That is, the bridge control circuit 12 is in an invalid mode in which the voltage signal output from the polarity detection circuit 11 is invalidated.
  • Step S102 Yes.
  • the switch control unit 15 closes the switch 14 by outputting an enable signal to the switch 14 (step S103), and ends the start-up process.
  • DC power is supplied from the diode bridge DB1 to the power conversion circuit 2, and the switches SW11, SW12, SW13, of the bridge control circuit 12 from the power conversion circuit 2 are based on the polarity of the voltage detected by the polarity detection circuit 11.
  • a voltage is applied to any two of the SW14s. Specifically, the switch SW11 and the switch SW12 are closed, and the switch SW13 and the switch SW14 are opened (or, the switch SW11 and the switch SW12 are opened, and the switch SW13 and the switch SW14 are closed). That is, the bridge control circuit 12 is in an effective mode for validating the voltage signal output from the polarity detection circuit 11.
  • the switch control unit 15 After the switch control unit 15 starts supplying power from the AC power supply AC at time T0, all the voltages between the output terminals teah and steel are preset for each period ⁇ T. It is assumed that it is determined whether or not the voltage range is within the ⁇ Vth.
  • the bridge control circuit 12 maintains the invalid mode immediately after the power supply from the AC power supply AC is started at time T0. Then, when the switch control unit 15 determines that the voltage between the output terminal teah and the steel is out of the voltage range ⁇ Vth during the period between the time T0 and the time T1, the switch 14 is maintained in the open state.
  • the bridge control circuit 12 maintains the invalid mode because no voltage is applied from the power conversion circuit 2 to the switches SW11, SW12, SW13, and SW14. Further, when the switch control unit 15 determines that the voltage between the output terminal teah and the steel is out of the voltage range ⁇ Vth during the period between the time T1 and the time T2, the bridge control circuit 12 similarly sets the invalid mode. maintain. After that, when the switch control unit 15 determines that the voltage between the output terminal teah and the steel is within the voltage range ⁇ Vth in the period between the time T2 and the time T3, the switch 14 is closed. In this case, a voltage is applied from the power conversion circuit 2 to the switches SW11, SW12, SW13, and SW14, and the bridge control circuit 12 switches from the invalid mode to the effective mode.
  • the bridge control circuit 12 has a diode bridge DB1 within a preset period immediately after the supply of the AC voltage to the diode bridge DB1 is started.
  • the switch 14 is maintained in the open state until the voltage between the output terminal teoh and the teol changes within the preset voltage range ⁇ Vth.
  • the voltage between the output terminal teah and teol of the diode bridge DB1 often deviates from the voltage range ⁇ Vth due to the disturbance being superimposed on the AC voltage input from the AC power supply AC.
  • the disturbance is reduced by the rectifying diodes D11, D12, D13, D14 constituting the diode bridge DB1. Therefore, the stress applied to the various elements constituting the power conversion circuit 2 connected to the subsequent stage of the diode bridge DB1 due to the disturbance of the AC voltage input to the diode bridge DB1 is reduced.
  • the power conversion circuit 2 has a booster circuit that boosts the voltage to a voltage higher than the output voltage of the diode bridge DB1. Then, when the bridge control circuit 12 is connected to the cathode of the diode D2 forming a part of the booster circuit and the switch 14 is kept in the closed state, when the voltage output from the booster circuit is applied, the polarity A voltage is applied to the switches SW1, SW2, SW3, and SW4 according to the voltage signal output from the detection circuit 11. As a result, it is not necessary to separately provide a voltage source for driving the bridge control circuit 12, so that the configuration of the power supply circuit can be simplified.
  • the power conversion circuit 202 may be a forward type DC-DC converter.
  • the power conversion circuit 202 includes transformers TR21 and TR22, switching elements Q221, Q222, and Q223, a drive circuit 221 and capacitors C21, C22, C23, and a diode D22.
  • the transformer TR21 has a coil L211 on the primary side and a coil L212 on the secondary side that are inductively coupled to each other.
  • the transformer TR22 has a coil L221 on the primary side and a coil L222 on the secondary side that are inductively coupled to each other.
  • One end of the coil L221 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the anode of the diode D22.
  • One end of the coil L222 is connected to the output end teoh2 on the high potential side of the power conversion circuit 202, and the other end is connected to the switching element Q222.
  • the switching element Q221 is connected between the other end of the coil L211 of the transformer TR21 and the switch 14.
  • the drain of the switching element Q221 is connected to the other end of the coil L211 of the transformer TR21, and the source of the switching element Q221 is connected to the switch 14.
  • the switching element Q222 is connected between the other end of the coil L212 of the transformer TR21 and the other end of the coil L221 of the transformer TR22.
  • the source of the switching element Q222 is connected to the other end of the coil L212 of the transformer TR21, and the drain of the switching element Q222 is connected to the other end of the coil L221 of the transformer TR22.
  • the switching element Q223 is connected between one end of the coil L212 of the transformer TR21 and the other end of the coil L221 of the transformer TR22.
  • the drain of the switching element Q223 is connected to one end of the coil L212 of the transformer TR21
  • the source of the switching element Q223 is connected to the other end of the coil L221 of the transformer TR22.
  • the drive circuit 221 is connected to the output end teah on the high potential side of the diode bridge DB1, receives DC power from the diode bridge DB1, and outputs a control signal to the gates of the switching elements Q221, Q222, and Q223.
  • the switching elements Q221, Q222, and Q223 are turned on and off by the control signal input from the drive circuit 221.
  • the anode is connected to the other end of the coil L221 of the transformer TR22, and the cathode is connected to the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12.
  • the booster circuit is composed of the coils L211 and L221, the switching element Q221, and the diode D22.
  • each switch SW11, SW12, SW13, SW14 of the bridge control circuit 12 is boosted to a voltage higher than the output voltage of the diode bridge DB1, in other words, a DC voltage is superimposed on the output voltage of the diode bridge DB1. Apply the voltage.
  • the bridge control circuit 12 has switches SW11, SW12, SW13, and SW14 corresponding to the switches SW1, SW2, SW3, and SW4, respectively.
  • the present invention is not limited to this, and as shown in FIG. 7, for example, the bridge control circuit 3012 may have only the switching elements SW11 and SW13 corresponding to the switches SW1 and SW3.
  • the bridge control circuit 4012 may have only the switching elements SW12 and SW14 corresponding to the switches SW2 and SW4.
  • the same reference numerals as those in FIG. 1 are attached to the same configurations as those in the embodiment.
  • the power conversion circuit 402 includes a transformer TR41, switching elements Q21 and Q22, a drive circuit 21, capacitors C21, C22 and C23, and a diode D2.
  • the transformer TR41 has a coil L411 on the primary side and coils L412 and L2 on the secondary side. One end of the coil L411 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the switching element Q21. One end of the coil L412 is connected to the output end teol on the low potential side of the diode bridge DB1, and the other end is connected to the anode of the diode D2.
  • the circuit configurations of the bridge control circuits 3012 and 4012 can be simplified.
  • the present invention is suitable as a switching power supply circuit and a PoE power supply circuit.
  • 2,202,402 Power conversion circuit
  • 11 Polarity detection circuit
  • 12,301,4012 Bridge control circuit, 14, SW1, SW2, SW3, SW4, SW11, SW12, SW13, SW14: Switch
  • 15 Switch control Units 21,221: Drive circuit
  • 112 Inversion circuit
  • DB1 Diode bridge, L11, L12, L2, L211, L212, L221, L222, L411, L412: Coil, Q21, Q22, Q221, Q222, Q223: Switching element, tei1, tei2: Input end, te111, te112, te113, te114, teoh, teol, teoh2, teol2: output terminal, TR1, TR21

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

Abstract

This power supply circuit comprises: a diode bridge (DB1) that rectifies a voltage; switches (SW1, SW2, SW3, SW4) respectively connected in parallel to diodes (D11, D12, D13, D14) constituting the diode bridge (DB1); a polarity detection circuit (11) that detects the polarity of the voltage; and a bridge control circuit (12) that controls opened/closed states of the switches (SW1, SW2, SW3, SW4). Also, the bridge control circuit (12) maintains the switches (SW1, SW2, SW3, SW4) in an opened state until the voltage between output ends of the diode bridge (DB1) changes within a preset voltage range.

Description

電源回路Power circuit
　本発明は、電源回路に関する。 The present invention relates to a power supply circuit.
　入力される電圧の極性を検出する極性検出回路と、ブリッジ整流ダイオードの各素子に並列に接続したスイッチ回路と、極性検出回路で検出した検出結果に基づき、前述のスイッチ回路の開閉を行うことにより、整流ダイオードに流れる順方向電流をバイパスする手段と、を備えるＰｏＥ電源回路が提案されている（例えば特許文献１参照）。 By opening and closing the switch circuit described above based on the polarity detection circuit that detects the polarity of the input voltage, the switch circuit connected in parallel to each element of the bridge rectifier diode, and the detection result detected by the polarity detection circuit. A PoE power supply circuit including a means for bypassing a forward current flowing through a rectifier diode has been proposed (see, for example, Patent Document 1).
特開２００９－１１０９３号公報JP-A-2009-11093
　ところで、特許文献１に記載されたＰｏＥ電源回路では、スイッチ回路が閉状態の場合において、入力電圧に外乱が重畳していると、その外乱がスイッチ回路を介してブリッジ整流ダイオードの後段に接続された回路へ伝達されてしまう。この場合、ブリッジ整流ダイオードの後段に接続された回路を構成する各種素子に大きなストレスを与えてしまう虞がある。 By the way, in the PoE power supply circuit described in Patent Document 1, when the switch circuit is in the closed state and the disturbance is superimposed on the input voltage, the disturbance is connected to the subsequent stage of the bridge rectifier diode via the switch circuit. It will be transmitted to the circuit. In this case, there is a risk of giving a large stress to various elements constituting the circuit connected to the subsequent stage of the bridge rectifier diode.
　本発明は、上記事由に鑑みてなされたものであり、入力電圧に外乱が重畳した場合においてダイオードブリッジの後段に接続された回路を構成する素子に与えるストレスを低減できる電源回路を提供することを目的とする。 The present invention has been made in view of the above reasons, and provides a power supply circuit capable of reducing stress applied to elements constituting a circuit connected to the subsequent stage of a diode bridge when a disturbance is superimposed on an input voltage. The purpose.
　上記目的を達成するために、本発明に係る電源回路は、
　電圧を整流するダイオードブリッジと、
　前記ダイオードブリッジを構成するダイオードそれぞれに並列に接続された複数の第１スイッチと、
　前記電圧の極性を検出する極性検出回路と、
　前記極性検出回路により検出される前記電圧の極性と、前記ダイオードブリッジの出力端間の電圧とに基づいて、前記第１スイッチの開閉状態を制御するブリッジ制御回路と、を備え、
　前記ブリッジ制御回路は、前記ダイオードブリッジの出力端間の電圧が予め設定された電圧範囲内で推移する状態になるまで、電流が流れる経路に配置される少なくとも１つの前記第１スイッチを開状態で維持する。 In order to achieve the above object, the power supply circuit according to the present invention
A diode bridge that rectifies the voltage and
A plurality of first switches connected in parallel to each of the diodes constituting the diode bridge,
A polarity detection circuit that detects the polarity of the voltage and
A bridge control circuit that controls an open / closed state of the first switch based on the polarity of the voltage detected by the polarity detection circuit and the voltage between the output ends of the diode bridge is provided.
The bridge control circuit keeps at least one of the first switches open in the path through which the current flows until the voltage between the output ends of the diode bridge changes within a preset voltage range. maintain.
　また、本発明に係る電源回路は、
　前記ダイオードブリッジと前記ダイオードブリッジの後段に接続される後段回路との間に直列に接続される第２スイッチと、
　前記ダイオードブリッジの出力端間の電圧を検出する電圧検出部と、
　前記電圧検出部により検出される電圧が予め設定された電圧範囲内で推移する状態になるまで、前記第２スイッチを開状態で維持するスイッチ制御部と、を更に備える、ものであってもよい。 Further, the power supply circuit according to the present invention is
A second switch connected in series between the diode bridge and a subsequent circuit connected to the subsequent stage of the diode bridge,
A voltage detector that detects the voltage between the output ends of the diode bridge,
It may further include a switch control unit that keeps the second switch in an open state until the voltage detected by the voltage detection unit changes within a preset voltage range. ..
　また、本発明に係る電源回路は、
　前記極性検出回路が、前記電圧の極性を検出し、検出した極性に応じた電圧信号を出力し、
　前記ブリッジ制御回路が、前記後段回路から電力が供給されている場合、前記電圧信号が前記ブリッジ制御回路へ入力されることにより、前記極性検出回路により検出される前記電圧の極性に基づいて、前記第１スイッチを開閉させ、前記後段回路から電力が供給されない場合、前記第１スイッチが開状態となるよう維持する、ものであってもよい。 Further, the power supply circuit according to the present invention is
The polarity detection circuit detects the polarity of the voltage and outputs a voltage signal corresponding to the detected polarity.
When the bridge control circuit is supplied with power from the subsequent circuit, the voltage signal is input to the bridge control circuit, and the voltage signal is detected by the polarity detection circuit. The first switch may be opened and closed, and when power is not supplied from the subsequent circuit, the first switch may be maintained in an open state.
　また、本発明に係る電源回路は、
　前記後段回路が、前記ダイオードブリッジの出力電圧よりも高い電圧に昇圧する昇圧回路を有し、
　前記ブリッジ制御回路が、前記昇圧回路の出力端に接続され、前記電圧信号が前記ブリッジ制御回路へ入力されると、前記電圧信号に応じて前記昇圧回路から出力される電圧が前記第１スイッチへ印加される、ものであってもよい。 Further, the power supply circuit according to the present invention is
The subsequent circuit has a booster circuit that boosts the voltage to a voltage higher than the output voltage of the diode bridge.
When the bridge control circuit is connected to the output end of the booster circuit and the voltage signal is input to the bridge control circuit, the voltage output from the booster circuit is sent to the first switch in response to the voltage signal. It may be applied.
　また、本発明に係る電源回路は、
　前記ダイオードブリッジの後段に接続された後段回路が、前記ダイオードブリッジから入力される直流電圧を変換する電力変換回路であってもよい。 Further, the power supply circuit according to the present invention is
The subsequent circuit connected to the subsequent stage of the diode bridge may be a power conversion circuit that converts a DC voltage input from the diode bridge.
　本発明によれば、ブリッジ制御回路が、ダイオードブリッジの出力端間の電圧が予め設定された電圧範囲内で推移する状態になるまで第１スイッチを開状態で維持する。これにより、入力電圧に重畳する外乱がダイオードブリッジで低減されるため、ダイオードブリッジの後段に接続された回路を構成する素子に与えるストレスを低減することができる。 According to the present invention, the bridge control circuit maintains the first switch in the open state until the voltage between the output ends of the diode bridge changes within a preset voltage range. As a result, the disturbance superimposed on the input voltage is reduced by the diode bridge, so that the stress applied to the elements constituting the circuit connected to the subsequent stage of the diode bridge can be reduced.
本発明の実施の形態に係る電源回路および電力変換回路を示す回路図である。It is a circuit diagram which shows the power supply circuit and the power conversion circuit which concerns on embodiment of this invention. 実施の形態に係る極性検出回路を示す回路図である。It is a circuit diagram which shows the polarity detection circuit which concerns on embodiment. 実施の形態に係る電源回路の動作を説明するための回路図である。It is a circuit diagram for demonstrating the operation of the power supply circuit which concerns on embodiment. 図３Ａの場合に対して入力電圧の極性が逆の場合における実施の形態に係る電源回路の動作を説明するための回路図である。It is a circuit diagram for demonstrating the operation of the power supply circuit which concerns on embodiment when the polarity of an input voltage is opposite to the case of FIG. 3A. 実施の形態に係るスイッチ制御部が実行する電源回路を起動させるための起動処理の流れの一例を示すフローチャートである。It is a flowchart which shows an example of the flow of the activation process for activating the power supply circuit executed by the switch control unit which concerns on embodiment. 実施の形態に係るスイッチ制御回路の動作説明図である。It is operation explanatory drawing of the switch control circuit which concerns on embodiment. 変形例に係る電源回路の回路図である。It is a circuit diagram of the power supply circuit which concerns on a modification. 変形例に係る電源回路の回路図である。It is a circuit diagram of the power supply circuit which concerns on a modification. 変形例に係る電源回路の回路図である。It is a circuit diagram of the power supply circuit which concerns on a modification.
　以下、本発明の実施の形態について図面を参照して詳細に説明する。本実施の形態に係る電源回路は、入力端に印加された交流電圧を整流するダイオードブリッジと、ダイオードブリッジを構成するダイオードそれぞれに並列に接続された第１スイッチと、入力端に印加された電圧の極性を検出する極性検出回路と、第１スイッチの開閉状態を制御するブリッジ制御回路と、を備える。そして、ブリッジ制御回路は、ダイオードブリッジの入力端に交流電圧が印加されてから、ダイオードブリッジの出力端間の電圧が予め設定された電圧範囲内で予め設定された期間推移する状態になるまで第１スイッチを開状態で維持する。そして、予め設定された電圧範囲内で予め設定された期間推移する状態になった場合、外乱がおさまったとして、ブリッジ制御回路は、極性検出回路の極性に基づいて、第１スイッチＳＷ１、ＳＷ２を閉状態、もしくは、第１スイッチＳＷ３、ＳＷ４を閉状態にする。次に、本実施の形態に係る電源回路の構成について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The power supply circuit according to the present embodiment includes a diode bridge that rectifies the AC voltage applied to the input terminal, a first switch connected in parallel to each of the diodes constituting the diode bridge, and a voltage applied to the input terminal. A polarity detection circuit for detecting the polarity of the first switch and a bridge control circuit for controlling the open / closed state of the first switch are provided. Then, in the bridge control circuit, after the AC voltage is applied to the input end of the diode bridge, the voltage between the output ends of the diode bridge changes within a preset voltage range for a preset period. 1 Keep the switch open. Then, when the state changes for a preset period within a preset voltage range, the bridge control circuit switches the first switches SW1 and SW2 based on the polarity of the polarity detection circuit, assuming that the disturbance has subsided. The closed state or the first switches SW3 and SW4 are closed. Next, the configuration of the power supply circuit according to the present embodiment will be described in detail.
　本実施の形態に係る電源回路は、図１に示すように、入力端ｔｅｉ１、ｔｅｉ２と出力端ｔｅｏｈ、ｔｅｏｌとを有するダイオードブリッジＤＢ１と、入力端ｔｅｉ１、ｔｅｉ２間に印加される電圧の極性を検出する極性検出回路１１と、ダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ側（以下、後段と記載する）に接続された電力変換回路２と、を備え、電力変換回路２に接続された負荷Ｚへ直流電力を供給する。負荷Ｚは、電力変換回路２の出力端ｔｅｏｈ２、ｔｅｏｌ２間に接続されている。また、電源回路は、スイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４と、ブリッジ制御回路１２と、を備える。更に、電源回路は、ダイオードブリッジＤＢ１と電力変換回路２との間に接続されたスイッチ１４と、スイッチ１４を制御するスイッチ制御部１５と、ダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧を検出する電圧検出部１３１と、を備える。 In the power supply circuit according to the present embodiment, as shown in FIG. 1, the polarity of the voltage applied between the diode bridge DB1 having the input ends tei1 and tei2 and the output ends teoh and teol and the input ends tie1 and tei2 is determined. To the load Z connected to the power conversion circuit 2 including the polarity detection circuit 11 for detection, the output terminal teah of the diode bridge DB1, and the power conversion circuit 2 connected to the steel side (hereinafter, referred to as the latter stage). Supply DC power. The load Z is connected between the output ends teoh2 and teol2 of the power conversion circuit 2. Further, the power supply circuit includes switches SW1, SW2, SW3, SW4, and a bridge control circuit 12. Further, the power supply circuit detects the voltage between the switch 14 connected between the diode bridge DB1 and the power conversion circuit 2, the switch control unit 15 that controls the switch 14, and the output ends teah and teol of the diode bridge DB1. The voltage detection unit 131 is provided.
　ダイオードブリッジＤＢ１の入力端ｔｅｉ１、ｔｅｉ２の間には、交流電源ＡＣが接続されている。また、ダイオードブリッジＤＢ１の後段には、電力変換回路２が接続されている。ダイオードブリッジＤＢ１は、４つのダイオードＤ１１、Ｄ１２、Ｄ１３、Ｄ１４から構成されている。ダイオードＤ１１は、アノードが入力端ｔｅｉ１に接続され、カソードが入力端ｔｅｉ２に接続されている。ダイオードＤ１２は、アノードが出力端ｔｅｏｌに接続され、カソードが入力端ｔｅｉ２に接続されている。ダイオードＤ１３は、アノードが入力端ｔｅｉ２に接続され、カソードが出力端ｔｅｏｈに接続されている。ダイオードＤ１４は、アノードが出力端ｔｅｏｌに接続され、カソードが入力端ｔｅｉ１に接続されている。 An AC power supply AC is connected between the input ends tei1 and tei2 of the diode bridge DB1. Further, a power conversion circuit 2 is connected to the subsequent stage of the diode bridge DB1. The diode bridge DB1 is composed of four diodes D11, D12, D13 and D14. In the diode D11, the anode is connected to the input end tei1 and the cathode is connected to the input end tei2. In the diode D12, the anode is connected to the output end teol and the cathode is connected to the input end tei2. In the diode D13, the anode is connected to the input end tei2 and the cathode is connected to the output end teoh. In the diode D14, the anode is connected to the output end teol and the cathode is connected to the input end tei1.
　スイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４は、例えばＦＥＴ、バイポーラトランジスタを有し、４つのダイオードＤ１１、Ｄ１２、Ｄ１３、Ｄ１４それぞれに並列に接続された第１スイッチである。そして、ハイサイド側のスイッチＳＷ１、ＳＷ３には、Ｎチャネル型のＦＥＴを用いてもよい。Ｎチャネル型のＦＥＴは、閉状態にするために昇圧された電圧が必要となるため、誤作動で閉状態となる可能性が低く、より確実に外乱を抑制することができる。 The switches SW1, SW2, SW3, and SW4 are first switches having, for example, FETs and bipolar transistors and connected in parallel to each of the four diodes D11, D12, D13, and D14. An N-channel FET may be used for the switches SW1 and SW3 on the high side. Since the N-channel FET requires a boosted voltage to be in the closed state, it is unlikely that the N-channel FET will be closed due to a malfunction, and disturbance can be suppressed more reliably.
　極性検出回路１１は、例えば図２に示すように、例えばオペアンプを含んで構成されるコンパレータ１１１と、例えば反転増幅回路を含んで構成される反転回路１１２と、を備える。コンパレータ１１１は、交流電源ＡＣの一方の出力端側の接続点ａと他方の出力端側の接続点ｂとのそれぞれの電位を比較し、接続点ａの電位が接続点ｂの電位よりも高いとき、予め設定されたＨレベルの電圧信号を出力する。ここで、Ｈレベルは、スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４のターンオン電圧以上の規定の電圧に設定されている。この場合、反転回路１１２は、Ｈレベルの電圧信号が入力されると、論理を反転する変換をして予め設定されたＬレベルの電圧信号を出力する。ここで、Ｌレベルは、スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４のターンオン電圧未満の規定の電圧に設定されている。 The polarity detection circuit 11 includes, for example, as shown in FIG. 2, a comparator 111 including, for example, an operational amplifier, and an inverting circuit 112 including, for example, an inverting amplifier circuit. The comparator 111 compares the potentials of the connection point a on one output end side of the AC power supply AC and the connection point b on the other output end side, and the potential of the connection point a is higher than the potential of the connection point b. At that time, a preset H level voltage signal is output. Here, the H level is set to a specified voltage equal to or higher than the turn-on voltage of the switches SW11, SW12, SW13, and SW14. In this case, when the H level voltage signal is input, the inverting circuit 112 performs a conversion that inverts the logic and outputs a preset L level voltage signal. Here, the L level is set to a specified voltage lower than the turn-on voltage of the switches SW11, SW12, SW13, and SW14.
　一方、コンパレータ１１１は、接続点ａの電位が接続点ｂの電位よりも低いとき、前述のＬレベルの電圧信号を出力する。この場合、反転回路１１２は、Ｌレベルの電圧信号が入力されると、論理を反転する変換をして前述のＨレベルの電圧信号を出力する。 On the other hand, the comparator 111 outputs the above-mentioned L level voltage signal when the potential of the connection point a is lower than the potential of the connection point b. In this case, when the L level voltage signal is input, the inverting circuit 112 performs a conversion that inverts the logic and outputs the above-mentioned H level voltage signal.
　図１に戻って、電力変換回路２は、フライバック型のＤＣ－ＤＣコンバータであり、トランスＴＲ１と、スイッチング素子Ｑ２１、Ｑ２２と、駆動回路２１と、コンデンサＣ２１、Ｃ２２、Ｃ２３と、ダイオードＤ２と、を有する後段回路である。トランスＴＲ１は、互いに誘導結合される一次側のコイルＬ１１、Ｌ１２と二次側のコイルＬ２とを有する。コイルＬ１１は、一端がダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、他端がスイッチング素子Ｑ２１に接続されている。コイルＬ１２は、一端がダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、他端がダイオードＤ２のアノードに接続されている。コイルＬ２は、一端が電力変換回路２の高電位側の出力端ｔｅｏｈ２に接続され、他端がスイッチング素子Ｑ２２に接続されている。スイッチング素子Ｑ２１は、ＦＥＴであり、トランスＴＲ１のコイルＬ１１の他端とスイッチ１４との間に接続されている。ここで、スイッチング素子Ｑ２１のドレインが、トランスＴＲ１のコイルＬ１１の他端に接続され、スイッチング素子Ｑ２１のソースが、スイッチ１４に接続されている。スイッチング素子Ｑ２２は、トランスＴＲ１のコイルＬ２の他端と電力変換回路２の低電位側の出力端ｔｅｏｌ２との間に接続されている。ここで、スイッチング素子Ｑ２２のドレインが、トランスＴＲ１のコイルＬ２の他端に接続され、スイッチング素子Ｑ２２のソースが、出力端ｔｅｏｌ２に接続されている。駆動回路２１は、ダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、ダイオードブリッジＤＢ１から直流電力の供給を受けて、各スイッチング素子Ｑ２１、Ｑ２２のゲートへ制御信号を出力する。これにより、各スイッチング素子Ｑ２１、Ｑ２２が、駆動回路２１から入力される制御信号によりオンオフ動作する。 Returning to FIG. 1, the power conversion circuit 2 is a flyback type DC-DC converter, and includes a transformer TR1, switching elements Q21 and Q22, a drive circuit 21, capacitors C21, C22, C23, and a diode D2. It is a post-stage circuit having. The transformer TR1 has a primary coil L11 and L12 and a secondary coil L2 that are inductively coupled to each other. One end of the coil L11 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the switching element Q21. One end of the coil L12 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the anode of the diode D2. One end of the coil L2 is connected to the output end teoh2 on the high potential side of the power conversion circuit 2, and the other end is connected to the switching element Q22. The switching element Q21 is an FET and is connected between the other end of the coil L11 of the transformer TR1 and the switch 14. Here, the drain of the switching element Q21 is connected to the other end of the coil L11 of the transformer TR1, and the source of the switching element Q21 is connected to the switch 14. The switching element Q22 is connected between the other end of the coil L2 of the transformer TR1 and the output end teol2 on the low potential side of the power conversion circuit 2. Here, the drain of the switching element Q22 is connected to the other end of the coil L2 of the transformer TR1, and the source of the switching element Q22 is connected to the output end teol2. The drive circuit 21 is connected to the output terminal teh on the high potential side of the diode bridge DB1, receives DC power from the diode bridge DB1, and outputs a control signal to the gates of the switching elements Q21 and Q22. As a result, the switching elements Q21 and Q22 are turned on and off by the control signal input from the drive circuit 21.
　コンデンサＣ２１は、ダイオードブリッジＤＢ１から出力される直流電圧を平滑化するためのものであり、ダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈとスイッチ１４との間に接続されている。コンデンサＣ２２は、電力変換回路２から出力される直流電圧を安定化させるためのものであり、電力変換回路２の出力端ｔｅｏｈ２、ｔｅｏｌ２間に接続されている。ダイオードＤ２は、アノードがトランスＴＲ１のコイルＬ１２の他端に接続され、カソードがブリッジ制御回路１２の各スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４に接続されている。コンデンサＣ２３は、後述するブリッジ制御回路１２の各スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４へ出力する電圧を安定化させるためのものであり、ダイオードＤ２のカソードとダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈとの間に接続されている。ここで、コイルＬ１１、Ｌ１２、スイッチング素子Ｑ２１およびダイオードＤ２から昇圧回路が構成される。この昇圧回路は、ブリッジ制御回路１２の各スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４に、ダイオードブリッジＤＢ１の出力電圧よりも高い電圧に昇圧した電圧、言い換えると、ダイオードブリッジＤＢ１の出力電圧に直流電圧を重畳してなる電圧を印加する。 The capacitor C21 is for smoothing the DC voltage output from the diode bridge DB1, and is connected between the output end teah on the high potential side of the diode bridge DB1 and the switch 14. The capacitor C22 is for stabilizing the DC voltage output from the power conversion circuit 2, and is connected between the output ends teoh2 and teol2 of the power conversion circuit 2. In the diode D2, the anode is connected to the other end of the coil L12 of the transformer TR1, and the cathode is connected to the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12. The capacitor C23 is for stabilizing the voltage output to each of the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12, which will be described later, and is the cathode of the diode D2 and the output end teah on the high potential side of the diode bridge DB1. Is connected to. Here, the booster circuit is composed of the coils L11 and L12, the switching element Q21, and the diode D2. In this booster circuit, each switch SW11, SW12, SW13, SW14 of the bridge control circuit 12 is boosted to a voltage higher than the output voltage of the diode bridge DB1, in other words, a DC voltage is superimposed on the output voltage of the diode bridge DB1. Apply the voltage.
　ブリッジ制御回路１２は、極性検出回路１１により検出される電圧の極性と、ダイオードブリッジＤＢ１の出力端間の電圧と、に基づいて、スイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４の開閉状態を制御する。ブリッジ制御回路１２は、スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４を有する。スイッチＳＷ１１は、極性検出回路１１の出力端ｔｅ１１１とスイッチＳＷ１との間に接続されている。スイッチＳＷ１２は、極性検出回路１１の出力端ｔｅ１１２とスイッチＳＷ２との間に接続されている。スイッチＳＷ１３は、極性検出回路１１の出力端ｔｅ１１３とスイッチＳＷ３との間に接続されている。スイッチＳＷ１４は、極性検出回路１１の出力端ｔｅ１１４とスイッチＳＷ４との間に接続されている。そして、電力変換回路２へ電力が供給されていない状態では、極性検出回路１１から入力される電圧信号のレベルに関わらず、スイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４は、開状態で維持される。 The bridge control circuit 12 controls the open / closed state of the switches SW1, SW2, SW3, and SW4 based on the polarity of the voltage detected by the polarity detection circuit 11 and the voltage between the output ends of the diode bridge DB1. The bridge control circuit 12 has switches SW11, SW12, SW13, and SW14. The switch SW11 is connected between the output terminal te111 of the polarity detection circuit 11 and the switch SW1. The switch SW12 is connected between the output terminal te112 of the polarity detection circuit 11 and the switch SW2. The switch SW13 is connected between the output terminal te113 of the polarity detection circuit 11 and the switch SW3. The switch SW14 is connected between the output terminal te114 of the polarity detection circuit 11 and the switch SW4. Then, in a state where power is not supplied to the power conversion circuit 2, the switches SW1, SW2, SW3, and SW4 are maintained in an open state regardless of the level of the voltage signal input from the polarity detection circuit 11.
　スイッチ１４は、ダイオードブリッジＤＢ１から電力変換回路２へ電流が流れる経路に配置される第２スイッチである。スイッチ１４は、ダイオードブリッジＤＢ１から電力変換回路２へ電力が供給されている状態とダイオードブリッジＤＢ１から電力変換回路２への電力供給が遮断された状態とのいずれかに切り替える。このスイッチ１４は、ダイオードブリッジＤＢ１の低電位側の出力端ｔｅｏｌと、ダイオードブリッジＤＢ１の後段に接続される電力変換回路２との間に接続されている。 The switch 14 is a second switch arranged in a path through which a current flows from the diode bridge DB1 to the power conversion circuit 2. The switch 14 switches between a state in which power is being supplied from the diode bridge DB1 to the power conversion circuit 2 and a state in which the power supply from the diode bridge DB1 to the power conversion circuit 2 is cut off. This switch 14 is connected between the output terminal electricity on the low potential side of the diode bridge DB1 and the power conversion circuit 2 connected to the subsequent stage of the diode bridge DB1.
　スイッチ制御部１５は、例えば専用のハードウェアで構成され、電圧検出部１３１により検出される、予め設定された期間内におけるダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が予め設定された電圧範囲内で推移しているか否かに基づいて、スイッチ１４の開閉状態を制御する。ここで、予め設定された期間の長さは、例えば１ｍｓｅｃに設定される。また、電圧範囲は、例えばＩＥＥＥ規格に基づいて設定され、３０Ｖ以上５７Ｖ以下の範囲に設定される。スイッチ制御部１５は、予め設定された期間内におけるダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が予め設定された電圧範囲内で推移している場合、スイッチ１４へイネーブル信号を出力してスイッチ１４を閉状態にする。 The switch control unit 15 is composed of, for example, dedicated hardware, and the voltage between the output terminals teah and steel of the diode bridge DB1 within a preset period detected by the voltage detection unit 131 is a preset voltage range. The open / closed state of the switch 14 is controlled based on whether or not the transition is within the range. Here, the length of the preset period is set to, for example, 1 msec. Further, the voltage range is set based on, for example, the IEEE standard, and is set in a range of 30 V or more and 57 V or less. The switch control unit 15 outputs an enable signal to the switch 14 to switch when the voltage between the output terminal teah and teol of the diode bridge DB1 is within the preset voltage range within a preset period. 14 is closed.
　次に、本実施の形態に係る電源回路の基本的な動作について図３Ａおよび図３Ｂを参照しながら説明する。ここでは、スイッチ制御部１５が、ダイオードブリッジの入力端に印加される電圧に重畳された外乱がおさまった状態（ダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が予め設定された電圧範囲内で予め設定された期間推移している状態）としてスイッチ１４へイネーブル信号を出力してスイッチ１４を閉状態にしているものとする。ここで、交流電源ＡＣの接続点ａ側の電位が接続点ｂ側の電位よりも高いとき、ブリッジ制御回路１２のスイッチＳＷ１１、ＳＷ１２が閉状態となり、スイッチＳＷ１３、ＳＷ１４が開状態となる。そして、ブリッジ制御回路１２からスイッチＳＷ１、ＳＷ２へＨレベルの電圧信号が入力され、ブリッジ制御回路１２からスイッチＳＷ３、ＳＷ４へＬレベルの電圧信号が入力される。このとき、図３Ａに示すようにスイッチＳＷ１、ＳＷ２が閉状態となり、スイッチＳＷ３、ＳＷ４が開状態となる。この場合、図３Ａの破線矢印で示すように、交流電源ＡＣの接続点ａ側の出力端から流出した電流が、ダイオードブリッジＤＢ１の入力端ｔｅｉ１に流入した後、ダイオードＤ１１をバイパスする閉状態のスイッチＳＷ１を経由してダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈから流出する。ダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈから流出した電流は、電力変換回路２を経由して、ダイオードブリッジＤＢ１の低電位側の出力端ｔｅｏｌに流入する。ダイオードブリッジＤＢ１の低電位側の出力端ｔｅｏｌに流入した電流は、ダイオードＤ１２をバイパスする閉状態のスイッチＳＷ２、入力端ｔｅｉ２を経由して交流電源ＡＣに戻る。 Next, the basic operation of the power supply circuit according to the present embodiment will be described with reference to FIGS. 3A and 3B. Here, the switch control unit 15 is in a state in which the disturbance superimposed on the voltage applied to the input terminal of the diode bridge has subsided (the voltage between the output terminals teah and steel of the diode bridge DB1 is within a preset voltage range. It is assumed that the enable signal is output to the switch 14 and the switch 14 is closed as a state in which the state has changed for a preset period. Here, when the potential on the connection point a side of the AC power supply AC is higher than the potential on the connection point b side, the switches SW11 and SW12 of the bridge control circuit 12 are in the closed state, and the switches SW13 and SW14 are in the open state. Then, the H level voltage signal is input from the bridge control circuit 12 to the switches SW1 and SW2, and the L level voltage signal is input from the bridge control circuit 12 to the switches SW3 and SW4. At this time, as shown in FIG. 3A, the switches SW1 and SW2 are in the closed state, and the switches SW3 and SW4 are in the open state. In this case, as shown by the broken line arrow in FIG. 3A, the current flowing out from the output end on the connection point a side of the AC power supply AC flows into the input end tee1 of the diode bridge DB1 and then bypasses the diode D11 in the closed state. It flows out from the output end teah on the high potential side of the diode bridge DB1 via the switch SW1. The current flowing out from the output terminal teah on the high potential side of the diode bridge DB1 flows into the output terminal teal on the low potential side of the diode bridge DB1 via the power conversion circuit 2. The current flowing into the output end teol on the low potential side of the diode bridge DB1 returns to the AC power supply AC via the closed switch SW2 and the input end tei2 that bypass the diode D12.
　一方、交流電源ＡＣの接続点ａ側の電位が接続点ｂ側の電位よりも低いとき、ブリッジ制御回路１２のスイッチＳＷ１１、ＳＷ１２が開状態となり、スイッチＳＷ１３、ＳＷ１４が閉状態となる。そして、ブリッジ制御回路１２からスイッチＳＷ１、ＳＷ２へＬレベルの電圧信号が入力され、ブリッジ制御回路１２からスイッチＳＷ３、ＳＷ４へＨレベルの電圧信号が入力される。このとき、図３Ｂに示すようにスイッチＳＷ１、ＳＷ２が開状態となり、スイッチＳＷ３、ＳＷ４が閉状態となる。この場合、図３Ｂの破線矢印で示すように、交流電源ＡＣの接続点ｂ側の出力端から流出した電流が、ダイオードブリッジＤＢ１の入力端ｔｅｉ２に流入した後、ダイオードＤ１３をバイパスする閉状態のスイッチＳＷ３を経由してダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈから流出する。ダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈから流出した電流は、電力変換回路２を経由して、ダイオードブリッジＤＢ１の低電位側の出力端ｔｅｏｌに流入する。ダイオードブリッジＤＢ１の低電位側の出力端ｔｅｏｌに流入した電流は、ダイオードＤ１４をバイパスする閉状態のスイッチＳＷ４、入力端ｔｅｉ１を経由して交流電源ＡＣに戻る。 On the other hand, when the potential on the connection point a side of the AC power supply AC is lower than the potential on the connection point b side, the switches SW11 and SW12 of the bridge control circuit 12 are in the open state, and the switches SW13 and SW14 are in the closed state. Then, the L level voltage signal is input from the bridge control circuit 12 to the switches SW1 and SW2, and the H level voltage signal is input from the bridge control circuit 12 to the switches SW3 and SW4. At this time, as shown in FIG. 3B, the switches SW1 and SW2 are in the open state, and the switches SW3 and SW4 are in the closed state. In this case, as shown by the broken line arrow in FIG. 3B, the current flowing out from the output end on the connection point b side of the AC power supply AC flows into the input end tee2 of the diode bridge DB1 and then bypasses the diode D13 in the closed state. It flows out from the output terminal teh on the high potential side of the diode bridge DB1 via the switch SW3. The current flowing out from the output terminal teah on the high potential side of the diode bridge DB1 flows into the output terminal teal on the low potential side of the diode bridge DB1 via the power conversion circuit 2. The current flowing into the output end teol on the low potential side of the diode bridge DB1 returns to the AC power supply AC via the closed switch SW4 that bypasses the diode D14 and the input end tee1.
　次に、本実施の形態に係るスイッチ制御部１５が実行する電源回路を起動させるための起動処理について図４を参照しながら説明する。まず、スイッチ制御部１５は、電圧検出部１３１により検出される、予め設定された期間内におけるダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧の履歴を取得する（ステップＳ１０１）。次に、スイッチ制御部１５は、取得したダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧の履歴に基づいて、予め設定された期間内における出力端ｔｅｏｈ、ｔｅｏｌ間の電圧の全てが電圧下限値Ｖｍｉｎｔｈ以上且つ電圧上限値Ｖｍａｘｔｈ以下の電圧範囲内であるか否かを判定する（ステップＳ１０２）。ここで、予め設定された期間は、前述のように、例えば１ｍｓｅｃに設定される。また、電圧下限値Ｖｍｉｎｔｈ、電圧上限値Ｖｍａｘｔｈは、前述のように、それぞれ、例えば３０Ｖ、５７Ｖに設定される。 Next, the activation process for activating the power supply circuit executed by the switch control unit 15 according to the present embodiment will be described with reference to FIG. First, the switch control unit 15 acquires the history of the voltage between the output terminals teah and teol of the diode bridge DB1 within a preset period detected by the voltage detection unit 131 (step S101). Next, in the switch control unit 15, based on the acquired history of the voltage between the output terminal teoh and teol of the diode bridge DB1, all the voltages between the output terminal teoh and teol within a preset period are the lower limit values. It is determined whether or not the voltage is within the voltage range of Vminth or more and the voltage upper limit value Vmaxth or less (step S102). Here, the preset period is set to, for example, 1 msec as described above. Further, the voltage lower limit value Vminth and the voltage upper limit value Vmaxth are set to, for example, 30V and 57V, respectively, as described above.
　ここにおいて、スイッチ制御部１５が、予め設定された期間内における出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が電圧下限値Ｖｍｉｎｔｈ以上且つ電圧上限値Ｖｍａｘｔｈ以下の電圧範囲内から外れていると判定したとする（ステップＳ１０２：Ｎｏ）。この場合、スイッチ制御部１５は、再びステップＳ１０１の処理を実行する。この場合、スイッチ１４が開状態で維持されるため、ダイオードブリッジＤＢ１から電力変換回路２へ直流電力が供給されず、電力変換回路２からブリッジ制御回路１２のスイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４それぞれへ電圧が印加されない。この場合、極性検出回路１１から出力される電圧信号に関わらずスイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４が開状態で維持される。即ち、ブリッジ制御回路１２は、極性検出回路１１から出力される電圧信号を無効にする無効モードとなる。 Here, it is assumed that the switch control unit 15 determines that the voltage between the output terminal teah and the steel within a preset period is out of the voltage range of the voltage lower limit value Vminth or more and the voltage upper limit value Vmaxth or less (). Step S102: No). In this case, the switch control unit 15 executes the process of step S101 again. In this case, since the switch 14 is maintained in the open state, DC power is not supplied from the diode bridge DB1 to the power conversion circuit 2, and the power conversion circuit 2 to the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12 respectively. No voltage is applied. In this case, the switches SW1, SW2, SW3, and SW4 are maintained in the open state regardless of the voltage signal output from the polarity detection circuit 11. That is, the bridge control circuit 12 is in an invalid mode in which the voltage signal output from the polarity detection circuit 11 is invalidated.
　一方、スイッチ制御部１５が、予め設定された期間内における出力端ｔｅｏｈ、ｔｅｏｌ間の電圧の全てが電圧下限値Ｖｍｉｎｔｈ以上且つ電圧上限値Ｖｍａｘｔｈ以下の電圧範囲内に収まっていると判定したとする（ステップＳ１０２：Ｙｅｓ）。この場合、スイッチ制御部１５は、スイッチ１４へイネーブル信号を出力することによりスイッチ１４を閉状態にし（ステップＳ１０３）、起動処理を終了する。この場合、ダイオードブリッジＤＢ１から電力変換回路２へ直流電力が供給され、極性検出回路１１により検出される電圧の極性に基づいて、電力変換回路２からブリッジ制御回路１２のスイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４のいずれか２つに電圧が印加される。具体的には、スイッチＳＷ１１とスイッチＳＷ１２を閉、且つ、スイッチＳＷ１３とスイッチＳＷ１４とを開とする（もしくは、スイッチＳＷ１１とスイッチＳＷ１２を開、かつ、スイッチＳＷ１３とスイッチＳＷ１４とを閉とする）。即ち、ブリッジ制御回路１２は、極性検出回路１１から出力される電圧信号を有効にする有効モードとなる。 On the other hand, it is assumed that the switch control unit 15 determines that all the voltages between the output terminal teoh and teol within a preset period are within the voltage range of the voltage lower limit value Vminth or more and the voltage upper limit value Vmaxth or less. (Step S102: Yes). In this case, the switch control unit 15 closes the switch 14 by outputting an enable signal to the switch 14 (step S103), and ends the start-up process. In this case, DC power is supplied from the diode bridge DB1 to the power conversion circuit 2, and the switches SW11, SW12, SW13, of the bridge control circuit 12 from the power conversion circuit 2 are based on the polarity of the voltage detected by the polarity detection circuit 11. A voltage is applied to any two of the SW14s. Specifically, the switch SW11 and the switch SW12 are closed, and the switch SW13 and the switch SW14 are opened (or, the switch SW11 and the switch SW12 are opened, and the switch SW13 and the switch SW14 are closed). That is, the bridge control circuit 12 is in an effective mode for validating the voltage signal output from the polarity detection circuit 11.
　例えば図５に示すように、スイッチ制御部１５が、時刻Ｔ０において交流電源ＡＣからの電力供給が開始された後、期間△Ｔ毎に出力端ｔｅｏｈ、ｔｅｏｌ間の電圧の全てが予め設定された電圧範囲△Ｖｔｈ内に収まっているか否かを判定していくとする。ここで、ブリッジ制御回路１２は、時刻Ｔ０において交流電源ＡＣからの電力供給が開始された直後の間、無効モードを維持する。そして、スイッチ制御部１５が、時刻Ｔ０から時刻Ｔ１の間の期間において、出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が電圧範囲△Ｖｔｈ外と判定するとスイッチ１４を開状態で維持する。この場合、ブリッジ制御回路１２は、電力変換回路２からスイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４に電圧が印加されないため、無効モードを維持する。また、スイッチ制御部１５が、時刻Ｔ１から時刻Ｔ２の間の期間において、出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が電圧範囲△Ｖｔｈ外と判定した場合、同様に、ブリッジ制御回路１２は、無効モードを維持する。その後、スイッチ制御部１５が、時刻Ｔ２から時刻Ｔ３の間の期間において、出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が電圧範囲△Ｖｔｈ内に収まっていると判定するとスイッチ１４を閉状態にする。この場合、電力変換回路２からスイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４に電圧が印加され、ブリッジ制御回路１２は、無効モードから有効モードに切り替わる。 For example, as shown in FIG. 5, after the switch control unit 15 starts supplying power from the AC power supply AC at time T0, all the voltages between the output terminals teah and steel are preset for each period ΔT. It is assumed that it is determined whether or not the voltage range is within the ΔVth. Here, the bridge control circuit 12 maintains the invalid mode immediately after the power supply from the AC power supply AC is started at time T0. Then, when the switch control unit 15 determines that the voltage between the output terminal teah and the steel is out of the voltage range ΔVth during the period between the time T0 and the time T1, the switch 14 is maintained in the open state. In this case, the bridge control circuit 12 maintains the invalid mode because no voltage is applied from the power conversion circuit 2 to the switches SW11, SW12, SW13, and SW14. Further, when the switch control unit 15 determines that the voltage between the output terminal teah and the steel is out of the voltage range ΔVth during the period between the time T1 and the time T2, the bridge control circuit 12 similarly sets the invalid mode. maintain. After that, when the switch control unit 15 determines that the voltage between the output terminal teah and the steel is within the voltage range ΔVth in the period between the time T2 and the time T3, the switch 14 is closed. In this case, a voltage is applied from the power conversion circuit 2 to the switches SW11, SW12, SW13, and SW14, and the bridge control circuit 12 switches from the invalid mode to the effective mode.
　以上説明したように、本実施の形態に係る電源回路によれば、ブリッジ制御回路１２が、ダイオードブリッジＤＢ１への交流電圧の供給が開始された直後から予め設定された期間内におけるダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が予め設定された電圧範囲△Ｖｔｈ内で推移する状態になるまでスイッチ１４を開状態で維持する。これにより、交流電源ＡＣから入力される交流電圧に外乱が重畳していることに起因して、ダイオードブリッジＤＢ１の出力端ｔｅｏｈ、ｔｅｏｌ間の電圧が電圧範囲△Ｖｔｈを外れることが頻発している状態では、外乱がダイオードブリッジＤＢ１を構成する整流ダイオードＤ１１、Ｄ１２、Ｄ１３、Ｄ１４により低減される。従って、ダイオードブリッジＤＢ１に入力される交流電圧の外乱に起因してダイオードブリッジＤＢ１の後段に接続された電力変換回路２を構成する各種素子に加わるストレスが低減される。 As described above, according to the power supply circuit according to the present embodiment, the bridge control circuit 12 has a diode bridge DB1 within a preset period immediately after the supply of the AC voltage to the diode bridge DB1 is started. The switch 14 is maintained in the open state until the voltage between the output terminal teoh and the teol changes within the preset voltage range ΔVth. As a result, the voltage between the output terminal teah and teol of the diode bridge DB1 often deviates from the voltage range ΔVth due to the disturbance being superimposed on the AC voltage input from the AC power supply AC. In the state, the disturbance is reduced by the rectifying diodes D11, D12, D13, D14 constituting the diode bridge DB1. Therefore, the stress applied to the various elements constituting the power conversion circuit 2 connected to the subsequent stage of the diode bridge DB1 due to the disturbance of the AC voltage input to the diode bridge DB1 is reduced.
　また、本実施の形態に係る電力変換回路２は、ダイオードブリッジＤＢ１の出力電圧よりも高い電圧に昇圧する昇圧回路を有する。そして、ブリッジ制御回路１２が、昇圧回路の一部を構成するダイオードＤ２のカソードに接続され、スイッチ１４を閉状態で維持している場合、昇圧回路から出力される電圧が印加されると、極性検出回路１１から出力される電圧信号に応じてスイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４へ電圧を印加する。これにより、ブリッジ制御回路１２を駆動するための電圧源を別途設ける必要が無くなるので、電源回路の構成を簡素化することができる。 Further, the power conversion circuit 2 according to the present embodiment has a booster circuit that boosts the voltage to a voltage higher than the output voltage of the diode bridge DB1. Then, when the bridge control circuit 12 is connected to the cathode of the diode D2 forming a part of the booster circuit and the switch 14 is kept in the closed state, when the voltage output from the booster circuit is applied, the polarity A voltage is applied to the switches SW1, SW2, SW3, and SW4 according to the voltage signal output from the detection circuit 11. As a result, it is not necessary to separately provide a voltage source for driving the bridge control circuit 12, so that the configuration of the power supply circuit can be simplified.
　以上、本発明の実施の形態について説明したが、本発明は前述の実施の形態の構成に限定されるものではない。例えば図６に示すように、電力変換回路２０２が、フォワード型のＤＣ－ＤＣコンバータであってもよい。なお、図６において、実施の形態と同様の構成については図１と同一の符号を付している。電力変換回路２０２は、トランスＴＲ２１、ＴＲ２２と、スイッチング素子Ｑ２２１、Ｑ２２２、Ｑ２２３と、駆動回路２２１と、コンデンサＣ２１、Ｃ２２、Ｃ２３と、ダイオードＤ２２と、を有する。トランスＴＲ２１は、互いに誘導結合される一次側のコイルＬ２１１と二次側のコイルＬ２１２とを有する。コイルＬ２１１は、一端がダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、他端がスイッチング素子Ｑ２２１に接続されている。コイルＬ２１２は、一端が電力変換回路２０２の高電位側の出力端ｔｅｏｈ２に接続され、他端がスイッチング素子Ｑ２２２に接続されている。トランスＴＲ２２は、互いに誘導結合される一次側のコイルＬ２２１と二次側のコイルＬ２２２とを有する。コイルＬ２２１は、一端がダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、他端がダイオードＤ２２のアノードに接続されている。コイルＬ２２２は、一端が電力変換回路２０２の高電位側の出力端ｔｅｏｈ２に接続され、他端がスイッチング素子Ｑ２２２に接続されている。 Although the embodiments of the present invention have been described above, the present invention is not limited to the configuration of the above-described embodiments. For example, as shown in FIG. 6, the power conversion circuit 202 may be a forward type DC-DC converter. In FIG. 6, the same reference numerals as those in FIG. 1 are attached to the same configurations as those in the embodiment. The power conversion circuit 202 includes transformers TR21 and TR22, switching elements Q221, Q222, and Q223, a drive circuit 221 and capacitors C21, C22, C23, and a diode D22. The transformer TR21 has a coil L211 on the primary side and a coil L212 on the secondary side that are inductively coupled to each other. One end of the coil L211 is connected to the output end teah on the high potential side of the diode bridge DB1, and the other end is connected to the switching element Q221. One end of the coil L212 is connected to the output end teoh2 on the high potential side of the power conversion circuit 202, and the other end is connected to the switching element Q222. The transformer TR22 has a coil L221 on the primary side and a coil L222 on the secondary side that are inductively coupled to each other. One end of the coil L221 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the anode of the diode D22. One end of the coil L222 is connected to the output end teoh2 on the high potential side of the power conversion circuit 202, and the other end is connected to the switching element Q222.
　スイッチング素子Ｑ２２１は、トランスＴＲ２１のコイルＬ２１１の他端とスイッチ１４との間に接続されている。ここで、スイッチング素子Ｑ２２１のドレインが、トランスＴＲ２１のコイルＬ２１１の他端に接続され、スイッチング素子Ｑ２２１のソースが、スイッチ１４に接続されている。スイッチング素子Ｑ２２２は、トランスＴＲ２１のコイルＬ２１２の他端とトランスＴＲ２２のコイルＬ２２１の他端との間に接続されている。ここで、スイッチング素子Ｑ２２２のソースが、トランスＴＲ２１のコイルＬ２１２の他端に接続され、スイッチング素子Ｑ２２２のドレインが、トランスＴＲ２２のコイルＬ２２１の他端に接続されている。スイッチング素子Ｑ２２３は、トランスＴＲ２１のコイルＬ２１２の一端とトランスＴＲ２２のコイルＬ２２１の他端との間に接続されている。ここで、スイッチング素子Ｑ２２３のドレインが、トランスＴＲ２１のコイルＬ２１２の一端に接続され、スイッチング素子Ｑ２２３のソースが、トランスＴＲ２２のコイルＬ２２１の他端に接続されている。駆動回路２２１は、ダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、ダイオードブリッジＤＢ１から直流電力の供給を受けて、各スイッチング素子Ｑ２２１、Ｑ２２２、Ｑ２２３のゲートへ制御信号を出力する。これにより、各スイッチング素子Ｑ２２１、Ｑ２２２、Ｑ２２３が、駆動回路２２１から入力される制御信号によりオンオフ動作する。ダイオードＤ２２は、アノードがトランスＴＲ２２のコイルＬ２２１の他端に接続され、カソードがブリッジ制御回路１２の各スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４に接続されている。ここで、コイルＬ２１１、Ｌ２２１、スイッチング素子Ｑ２２１およびダイオードＤ２２から昇圧回路が構成される。この昇圧回路は、ブリッジ制御回路１２の各スイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４に、ダイオードブリッジＤＢ１の出力電圧よりも高い電圧に昇圧した電圧、言い換えると、ダイオードブリッジＤＢ１の出力電圧に直流電圧を重畳してなる電圧を印加する。 The switching element Q221 is connected between the other end of the coil L211 of the transformer TR21 and the switch 14. Here, the drain of the switching element Q221 is connected to the other end of the coil L211 of the transformer TR21, and the source of the switching element Q221 is connected to the switch 14. The switching element Q222 is connected between the other end of the coil L212 of the transformer TR21 and the other end of the coil L221 of the transformer TR22. Here, the source of the switching element Q222 is connected to the other end of the coil L212 of the transformer TR21, and the drain of the switching element Q222 is connected to the other end of the coil L221 of the transformer TR22. The switching element Q223 is connected between one end of the coil L212 of the transformer TR21 and the other end of the coil L221 of the transformer TR22. Here, the drain of the switching element Q223 is connected to one end of the coil L212 of the transformer TR21, and the source of the switching element Q223 is connected to the other end of the coil L221 of the transformer TR22. The drive circuit 221 is connected to the output end teah on the high potential side of the diode bridge DB1, receives DC power from the diode bridge DB1, and outputs a control signal to the gates of the switching elements Q221, Q222, and Q223. As a result, the switching elements Q221, Q222, and Q223 are turned on and off by the control signal input from the drive circuit 221. In the diode D22, the anode is connected to the other end of the coil L221 of the transformer TR22, and the cathode is connected to the switches SW11, SW12, SW13, and SW14 of the bridge control circuit 12. Here, the booster circuit is composed of the coils L211 and L221, the switching element Q221, and the diode D22. In this booster circuit, each switch SW11, SW12, SW13, SW14 of the bridge control circuit 12 is boosted to a voltage higher than the output voltage of the diode bridge DB1, in other words, a DC voltage is superimposed on the output voltage of the diode bridge DB1. Apply the voltage.
　本構成によっても、実施の形態に係る電源回路と同様の作用効果を得ることができる。 Even with this configuration, the same operation and effect as the power supply circuit according to the embodiment can be obtained.
　実施の形態では、ブリッジ制御回路１２が、スイッチＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４それぞれに対応するスイッチＳＷ１１、ＳＷ１２、ＳＷ１３、ＳＷ１４を有する例について説明した。但し、これに限らず、例えば図７に示すように、ブリッジ制御回路３０１２が、スイッチＳＷ１、ＳＷ３に対応するスイッチング素子ＳＷ１１、ＳＷ１３のみを有するものであってもよい。 In the embodiment, an example in which the bridge control circuit 12 has switches SW11, SW12, SW13, and SW14 corresponding to the switches SW1, SW2, SW3, and SW4, respectively, has been described. However, the present invention is not limited to this, and as shown in FIG. 7, for example, the bridge control circuit 3012 may have only the switching elements SW11 and SW13 corresponding to the switches SW1 and SW3.
　或いは、例えば図８に示すように、ブリッジ制御回路４０１２が、スイッチＳＷ２、ＳＷ４に対応するスイッチング素子ＳＷ１２、ＳＷ１４のみを有するものであってもよい。なお、図８において、実施の形態と同様の構成については、図１と同一の符号を付している。ここで、電力変換回路４０２は、トランスＴＲ４１と、スイッチング素子Ｑ２１、Ｑ２２と、駆動回路２１と、コンデンサＣ２１、Ｃ２２、Ｃ２３と、ダイオードＤ２と、を有する。トランスＴＲ４１は、一次側のコイルＬ４１１と二次側のコイルＬ４１２、Ｌ２とを有する。コイルＬ４１１は、一端がダイオードブリッジＤＢ１の高電位側の出力端ｔｅｏｈに接続され、他端がスイッチング素子Ｑ２１に接続されている。コイルＬ４１２は、一端がダイオードブリッジＤＢ１の低電位側の出力端ｔｅｏｌに接続され、他端がダイオードＤ２のアノードに接続されている。 Alternatively, for example, as shown in FIG. 8, the bridge control circuit 4012 may have only the switching elements SW12 and SW14 corresponding to the switches SW2 and SW4. In FIG. 8, the same reference numerals as those in FIG. 1 are attached to the same configurations as those in the embodiment. Here, the power conversion circuit 402 includes a transformer TR41, switching elements Q21 and Q22, a drive circuit 21, capacitors C21, C22 and C23, and a diode D2. The transformer TR41 has a coil L411 on the primary side and coils L412 and L2 on the secondary side. One end of the coil L411 is connected to the output end teoh on the high potential side of the diode bridge DB1, and the other end is connected to the switching element Q21. One end of the coil L412 is connected to the output end teol on the low potential side of the diode bridge DB1, and the other end is connected to the anode of the diode D2.
　本構成によれば、ブリッジ制御回路３０１２、４０１２の回路構成を簡素化することができる。 According to this configuration, the circuit configurations of the bridge control circuits 3012 and 4012 can be simplified.
　以上、本発明の実施の形態および変形例について説明したが、本発明はこれらに限定されるものではない。本発明は、実施の形態および変形例が適宜組み合わされたもの、それに適宜変更が加えられたものを含む。 Although the embodiments and modifications of the present invention have been described above, the present invention is not limited thereto. The present invention includes an appropriate combination of embodiments and modifications, and an appropriate modification.
　本出願は、２０１９年８月２６日に出願された日本国特許出願特願２０１９－１５３９０６号に基づく。本明細書中に日本国特許出願特願２０１９－１５３９０６号の明細書、特許請求の範囲および図面全体を参照として取り込むものとする。 This application is based on Japanese Patent Application No. 2019-153906 filed on August 26, 2019. The specification, claims and the entire drawing of Japanese Patent Application No. 2019-153906 shall be incorporated into this specification as a reference.
　本発明は、スイッチング電源回路、ＰｏＥ電源回路として好適である。 The present invention is suitable as a switching power supply circuit and a PoE power supply circuit.
２，２０２，４０２：電力変換回路、１１：極性検出回路、１２，３０１２，４０１２：ブリッジ制御回路、１４、ＳＷ１、ＳＷ２、ＳＷ３、ＳＷ４，ＳＷ１１，ＳＷ１２，ＳＷ１３，ＳＷ１４：スイッチ、１５：スイッチ制御部、２１，２２１：駆動回路、１１１：コンパレータ、１１２：反転回路、１３１：電圧検出部、ａ，ｂ：接続点、Ｃ２１，Ｃ２２，Ｃ２３：コンデンサ、Ｄ２，Ｄ１１，Ｄ１２，Ｄ１３，Ｄ１４，Ｄ２２：ダイオード、ＤＢ１：ダイオードブリッジ、Ｌ１１，Ｌ１２，Ｌ２，Ｌ２１１，Ｌ２１２，Ｌ２２１，Ｌ２２２，Ｌ４１１，Ｌ４１２：コイル、Ｑ２１，Ｑ２２，Ｑ２２１，Ｑ２２２，Ｑ２２３：スイッチング素子、ｔｅｉ１，ｔｅｉ２：入力端、ｔｅ１１１，ｔｅ１１２，ｔｅ１１３，ｔｅ１１４，ｔｅｏｈ、ｔｅｏｌ，ｔｅｏｈ２，ｔｅｏｌ２：出力端、ＴＲ１，ＴＲ２１，ＴＲ２２，ＴＲ４１：トランス、Ｚ：負荷 2,202,402: Power conversion circuit, 11: Polarity detection circuit, 12,301,4012: Bridge control circuit, 14, SW1, SW2, SW3, SW4, SW11, SW12, SW13, SW14: Switch, 15: Switch control Units 21,221: Drive circuit, 111: Comparator, 112: Inversion circuit, 131: Voltage detection unit, a, b: Connection point, C21, C22, C23: Capacitor, D2, D11, D12, D13, D14, D22 : Diode, DB1: Diode bridge, L11, L12, L2, L211, L212, L221, L222, L411, L412: Coil, Q21, Q22, Q221, Q222, Q223: Switching element, tei1, tei2: Input end, te111, te112, te113, te114, teoh, teol, teoh2, teol2: output terminal, TR1, TR21, TR22, TR41: transformer, Z: load

Claims (5)

  1. 　電圧を整流するダイオードブリッジと、
    　前記ダイオードブリッジを構成するダイオードそれぞれに並列に接続された複数の第１スイッチと、
    　前記電圧の極性を検出する極性検出回路と、
    　前記極性検出回路により検出される前記電圧の極性と、前記ダイオードブリッジの出力端間の電圧とに基づいて、前記第１スイッチの開閉状態を制御するブリッジ制御回路と、を備え、
    　前記ブリッジ制御回路は、前記ダイオードブリッジの出力端間の電圧が予め設定された電圧範囲内で推移する状態になるまで、電流が流れる経路に配置される少なくとも１つの前記第１スイッチを開状態で維持する、
    　電源回路。     A diode bridge that rectifies the voltage and
    A plurality of first switches connected in parallel to each of the diodes constituting the diode bridge,
    A polarity detection circuit that detects the polarity of the voltage and
    A bridge control circuit that controls an open / closed state of the first switch based on the polarity of the voltage detected by the polarity detection circuit and the voltage between the output ends of the diode bridge is provided.
    The bridge control circuit keeps at least one of the first switches open in the path through which the current flows until the voltage between the output ends of the diode bridge changes within a preset voltage range. maintain,
    Power circuit.
  2. 　前記ダイオードブリッジと前記ダイオードブリッジの後段に接続される後段回路との間に直列に接続される第２スイッチと、
    　前記ダイオードブリッジの出力端間の電圧を検出する電圧検出部と、
    　前記電圧検出部により検出される電圧が予め設定された電圧範囲内で推移する状態になるまで、前記第２スイッチを開状態で維持するスイッチ制御部と、を更に備える、
    　請求項１に記載の電源回路。     A second switch connected in series between the diode bridge and a subsequent circuit connected to the subsequent stage of the diode bridge,
    A voltage detector that detects the voltage between the output ends of the diode bridge,
    A switch control unit that keeps the second switch in an open state until the voltage detected by the voltage detection unit changes within a preset voltage range is further provided.
    The power supply circuit according to claim 1.
  3. 　前記極性検出回路は、前記電圧の極性を検出し、検出した極性に応じた電圧信号を出力し、
    　前記ブリッジ制御回路は、前記後段回路から電力が供給されている場合、前記電圧信号が前記ブリッジ制御回路へ入力されることにより、前記極性検出回路により検出される前記電圧の極性に基づいて、前記第１スイッチを開閉させ、前記後段回路から電力が供給されない場合、前記第１スイッチが開状態となるよう維持する、
    　請求項２に記載の電源回路。     The polarity detection circuit detects the polarity of the voltage and outputs a voltage signal corresponding to the detected polarity.
    When power is supplied from the subsequent circuit, the bridge control circuit is based on the polarity of the voltage detected by the polarity detection circuit by inputting the voltage signal to the bridge control circuit. The first switch is opened and closed, and when power is not supplied from the subsequent circuit, the first switch is maintained in an open state.
    The power supply circuit according to claim 2.
  4. 　前記後段回路は、前記ダイオードブリッジの出力電圧よりも高い電圧に昇圧する昇圧回路を有し、
    　前記ブリッジ制御回路は、前記昇圧回路の出力端に接続され、前記電圧信号が前記ブリッジ制御回路へ入力されると、前記電圧信号に応じて前記昇圧回路から出力される電圧が前記第１スイッチへ印加される、
    　請求項３に記載の電源回路。     The subsequent circuit has a booster circuit that boosts the voltage to a voltage higher than the output voltage of the diode bridge.
    The bridge control circuit is connected to the output end of the booster circuit, and when the voltage signal is input to the bridge control circuit, the voltage output from the booster circuit is sent to the first switch in response to the voltage signal. Applied,
    The power supply circuit according to claim 3.
  5. 　前記ダイオードブリッジの後段に接続された後段回路は、前記ダイオードブリッジから入力される直流電圧を変換する電力変換回路である、
    　請求項１から４のいずれか１項に記載の電源回路。     The subsequent circuit connected to the subsequent stage of the diode bridge is a power conversion circuit that converts a DC voltage input from the diode bridge.
    The power supply circuit according to any one of claims 1 to 4.
PCT/JP2020/030794 2019-08-26 2020-08-13 Power supply circuit WO2021039424A1 (en)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1198610A (en) * 1997-09-22 1999-04-09 Toshiba Corp Controller for alternating current electric vehicle
JP2002034167A (en) * 2000-07-17 2002-01-31 Oki Electric Ind Co Ltd Power circuit
JP2002345250A (en) * 2001-05-11 2002-11-29 Tdk Corp Rectifier circuit
JP2009011093A (en) * 2007-06-28 2009-01-15 Toshiba Corp Poe power supply circuit of electric power receiving apparatus
US20090168278A1 (en) * 2007-12-26 2009-07-02 Silicon Laboratories Inc. Circuit device and method of supressing a power event
JP2012090394A (en) * 2010-10-18 2012-05-10 Toshiba Tec Corp Power conversion apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1198610A (en) * 1997-09-22 1999-04-09 Toshiba Corp Controller for alternating current electric vehicle
JP2002034167A (en) * 2000-07-17 2002-01-31 Oki Electric Ind Co Ltd Power circuit
JP2002345250A (en) * 2001-05-11 2002-11-29 Tdk Corp Rectifier circuit
JP2009011093A (en) * 2007-06-28 2009-01-15 Toshiba Corp Poe power supply circuit of electric power receiving apparatus
US20090168278A1 (en) * 2007-12-26 2009-07-02 Silicon Laboratories Inc. Circuit device and method of supressing a power event
JP2012090394A (en) * 2010-10-18 2012-05-10 Toshiba Tec Corp Power conversion apparatus

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