WO2013167046A2

WO2013167046A2 - Anti-surge bridgeless power factor correction circuit

Info

Publication number: WO2013167046A2
Application number: PCT/CN2013/079614
Authority: WO
Inventors: 李俊凯; 郑大成; 万正海; 戴彬传; 李丹; 浦锡锋
Original assignee: 中兴通讯股份有限公司
Priority date: 2012-11-19
Filing date: 2013-07-18
Publication date: 2013-11-14
Also published as: WO2013167046A3; CN103825447A

Abstract

Disclosed is an anti-surge bridgeless power factor correction (PFC) circuit, which comprises a bridgeless PFC circuit and a boost capacitor which are connected between an AC power supply and a load in sequence. The anti-surge bridgeless PFC circuit also comprises a protection unit, a switch unit and a control unit. When a surge merges into the input of the AC power supply, the control unit controls the switch unit to be conducted, so as to form return current and discharge surge energy through the protection unit, the boost capacitor and the switch unit, thereby being able to protect a bridgeless PFC circuit from the influence of the surge.

Description

Anti-surge bridgeless power factor correction circuit

The invention relates to anti-surge technology, in particular to an anti-surge bridgeless power factor correction (PFC) circuit. Background technique

With the increasing use of bridgeless PFC circuit topologies, in order to improve the efficiency of switching power supplies, more and more products tend to choose bridgeless PFC circuits as power factor correction solutions. To avoid excessive surge current at the input, the switch and boost diodes are damaged. This requires surge protection for the bridgeless PFC circuit.

In the prior art, a circuit unit for releasing surge energy in a bridgeless PFC circuit usually has no switching unit or a switching unit composed of a diode, and has the following problems: If there is no switching unit, the return current when the surge is released passes through another PFC inductor. Reflow, thus, adds another PFC inductor loss and electromagnetic compatibility (EMC) interference, low work efficiency and high noise, which is difficult to apply to real products; if a switching unit composed of diodes is used, the wave is released The reflow current during the surge is recirculated through the diode of the switching unit, resulting in large loss of the diode, low operating efficiency, and inability to meet the energy saving requirements. Summary of the invention

In view of this, the main purpose of the embodiments of the present invention is to provide a surge-proof bridgeless PFC circuit, which solves the problems of large device loss and low work efficiency in the existing anti-surge technology.

To achieve the above objective, the technical solution of the embodiment of the present invention is implemented as follows:

Embodiments of the present invention disclose a surge-proof bridgeless power factor correction PFC circuit, including a bridgeless PFC circuit and a boost capacitor sequentially connected between an AC power source and a load; The bridge PFC circuit further includes: a protection unit, a switch unit, and a control unit; wherein the first terminal of the protection unit is connected to the first output of the AC power source, the first input connected to the bridgeless PFC circuit, and the first connection of the switch unit a second terminal of the protection unit is connected to the second output of the AC power source, connected to the second input of the bridgeless PFC circuit, and connected to the second terminal of the switch unit; the third terminal of the protection unit is connected to the boosting capacitor High voltage output of the first plate, bridgeless PFC circuit;

The first terminal of the control unit is connected to the third terminal of the switch unit, and the second terminal of the control unit is connected to the fourth terminal of the switch unit;

The fifth terminal of the switching unit is connected to the second plate of the boosting capacitor and the low voltage output end of the bridgeless PFC circuit;

The control unit controls the switch unit to be in a conducting state during the positive and negative half cycles of the alternating current input. When the surge is connected to the input of the alternating current power source, the protection unit, the boosting capacitor and the switching unit form a reflow, and the surge is discharged. energy.

In the above solution, the protection unit includes: a first protection subunit and a second protection subunit;

The first terminal of the first protection subunit is connected to the first output of the AC power source, the first input of the bridgeless PFC circuit is connected, and the first terminal of the switch unit is connected, and the first terminal of the second protection subunit is connected a second output of the AC power source, a second input connected to the bridgeless PFC circuit, and a second terminal connected to the switch unit;

The second terminal of the first protection subunit is shorted to the second terminal of the second protection subunit, and is connected to the first plate of the boosting capacitor and the high voltage output end of the bridgeless PFC circuit;

The first protection subunit is in an on state only when the surge is serially connected to the positive half cycle of the AC power input, and the second protection subunit is in an ON state only when the surge is serially connected to the negative half cycle of the AC power input.

In the above solution, the switch unit includes a first switch subunit and a second switch subunit; among them,

The first terminal of the first switch subunit is connected to the first output of the AC power source and connected to the first input of the bridgeless PFC circuit, and the first terminal of the second switch subunit is connected to the second output of the AC power source, and Connecting a second input of the bridgeless PFC circuit;

The second terminal of the first switch subunit is connected to the first terminal of the control unit, and the second terminal of the second switch subunit is connected to the second terminal of the control unit;

The third terminal of the first switch subunit is shorted to the third terminal of the second switch subunit, and is connected to the second plate of the boosting capacitor and the low voltage output end of the bridgeless PFC circuit;

The first switch subunit is controlled by the control unit and is only in a conducting state during a negative half cycle of the AC power input; the second switch subunit is controlled by the control unit and is in an ON state only during the positive half cycle of the AC power input.

In the above scheme,

When the surge is serially connected to the positive half cycle of the AC power input, the control unit controls the second switch subunit to be turned on, and the first protection subunit, the boosting capacitor, and the second switch subunit form a reflow, venting surge Energy

When the surge is serially connected to the negative half cycle of the AC power input, the control unit controls the first switch subunit to be turned on, and the second guard subunit, the boost capacitor and the first switch subunit form a reflow, and the venting surge energy.

In the above solution, the protection unit adopts a topology including a diode device.

In the above solution, the switching unit adopts a topology including a metal oxide semiconductor (MOSFET), an IGBT (Insulated Gate Bipolar Transistor) or a relay.

In the anti-surge bridgeless PFC circuit provided by the embodiment of the present invention, when a surge occurs, the control unit controls the switch unit to be in a conducting state during the positive and negative half cycles of the alternating current input, when the surge is input into the input of the alternating current power source. , the backflow is formed by the protection unit, the boosting capacitor and the switching unit, and the venting wave is released. The energy is surged, and the switching unit adopts a topology including a MOSFET, an IGBT or a relay, and the device is low in loss and high in work efficiency when the surge is released. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a circuit schematic diagram of an embodiment of a surge-proof bridgeless PFC circuit of the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

1 is a schematic structural diagram of a surge-proof bridgeless PFC circuit according to an embodiment of the present invention. As shown in FIG. 1, the surge-proof bridgeless PFC circuit includes a bridgeless connection between an AC power source and a load.

a PFC circuit 14 and a boost capacitor; wherein the bridgeless PFC circuit 14 and the boost capacitor are existing bridgeless PFC circuit topologies;

As shown in FIG. 2, the bridgeless PFC circuit 14 includes: boost inductors L1 and L2, booster diodes VD3 and VD4, and booster switches VT1 and VT2;

The anode of the boost diode VD3 is connected to the second terminal of the boost inductor L1, the drain of the boost switch VT1; the cathode of the boost diode VD3 is connected to the cathode of the boost diode VD4, boost capacitor

The first plate of C1, the high voltage output terminal of the bridgeless PFC circuit 14 Vdc+;

The anode of the boost diode VD4 is connected to the second terminal of the boost inductor L2, the drain of the boost switch transistor VT2, and the cathode of the boost diode VD4 is connected to the first plate of the boost capacitor C1 and the high voltage output of the bridgeless PFC circuit 14. End Vdc+;

The first terminal of the boost inductor L1 is connected to the first output of the alternating current power source;

The first terminal of the boost inductor L2 is connected to the second output of the alternating current power source;

The source of the step-up switch VT1 and VT2 is connected to the second plate of the boost capacitor C1, without bridge

The low voltage output of the PFC circuit 14 is Vdc -.

1 , the anti-surge bridgeless PFC circuit further includes: a protection unit 11, a control list Element 12 and switch unit 13; wherein

The first terminal of the protection unit 11 is connected to the first output of the AC power source, the first input of the bridgeless PFC circuit 14 is connected, and the first terminal of the switch unit 13 is connected, and the second terminal of the protection unit 11 is connected to the second output of the AC power source. a second input connected to the bridgeless PFC circuit 14 and connected to the second terminal of the switch unit 13; the third terminal of the protection unit 11 is connected to the first plate of the boost capacitor C1, and the high voltage output terminal Vdc+ of the bridgeless PFC circuit 14 ;

The first terminal of the control unit 12 is connected to the third terminal of the switch unit 13, and the second terminal of the control unit 12 is connected to the fourth terminal of the switch unit 13;

The fifth terminal of the switching unit 13 is connected to the second plate of the boosting capacitor C1, and the low voltage output terminal Vdc- of the bridgeless PFC circuit 14;

The control unit 12 controls the switch unit 13 to be in a conducting state during the positive and negative half cycles of the alternating current input. When the surge is connected to the input of the alternating current power source, the recirculation is formed by the guard unit 11, the boosting capacitor C1 and the switching unit 13 to discharge Surge energy.

Here, the protection unit 11 includes: a first protection subunit 111 and a second protection subunit 112;

The first terminal of the first protection subunit 111 is connected to the first output of the AC power source, the first input of the bridgeless PFC circuit 14 is connected, and the first terminal of the switch unit 13 is connected, and the first terminal of the second protection subunit 112 is connected. a second output of the AC power source, a second input connected to the bridgeless PFC circuit 14, and a second terminal connected to the switch unit 13;

The second terminal of the first protection subunit 111 and the second terminal of the second protection subunit 112 are shorted, and connected to the first plate of the boosting capacitor C1 and the high voltage output terminal Vdc+ of the bridgeless PFC circuit 14;

And,

The first protection sub-unit 111 is only in a conducting state when the surge is serially connected to the positive half cycle of the AC power input, and the second protection sub-unit 112 is only guided when the surge is connected to the negative half cycle of the AC power input. Pass state.

Here, the switch unit 13 includes a first switch subunit 131 and a second switch subunit 132;

The first terminal of the first switch subunit 131 is connected to the first output of the AC power source, and is connected to the first input of the bridgeless PFC circuit 14. The first terminal of the second switch subunit 132 is connected to the second output of the AC power source, and is connected. a second input of the bridgeless PFC circuit 14;

The second terminal of the first switch subunit 131 is connected to the first terminal of the control unit 12, and the second terminal of the second switch subunit 132 is connected to the second terminal of the control unit 12;

The third terminal of the first switch sub-unit 131 is short-circuited with the third terminal of the second switch sub-unit 132, and is connected to the second plate of the boost capacitor, the low-voltage output terminal Vdc- of the bridgeless PFC circuit 14;

The first switch subunit 131 is controlled by the control unit 12 and is only in the conducting state during the negative half cycle of the AC power input; the second switch subunit 132 is controlled by the control unit 12 and is only in the conducting state during the positive half cycle of the AC power input.

Here, when the surge is serially connected to the positive half cycle of the AC power input, the control unit 12 controls the second switch subunit 132 to be turned on to form through the first guard subunit 111, the boosting capacitor, and the second switch subunit 132. Reflux, venting surge energy;

When the surge is serially connected to the negative half cycle of the AC power input, the control unit 12 controls the first switch subunit 131 to be turned on to form a backflow through the second guard subunit 112, the boosting capacitor and the first switch subunit 131, and bleed. Surge energy.

Among them, the protection unit 11 adopts a topology including a diode device.

The first switch sub-unit 131 and the second switch sub-unit 132 in the switch unit 13 include a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an insulated gate bipolar transistor (IGBT, Insulated Gate Bipolar). Transtoror or a topology of a relay, wherein the topology employs one or more of the above devices; When the switch subunit adopts a single MOSFET topology, the first terminal of the switch subunit is the drain of the MOSFET, the second terminal of the switch subunit is the gate of the MOSFET, and the third terminal of the switch subunit is the MOSFET Source level

When the switch subunit adopts a single IGBT topology, the first terminal of the switch subunit is the collector of the IGBT, the second terminal of the switch subunit is the gate of the IGBT, and the third terminal of the switch subunit is the IGBT Emitter

When the switch subunit adopts a single relay topology, the first terminal of the switch subunit is a first power contact of the relay, and the second terminal of the switch subunit is a control circuit of a power coil of the relay, the switch subunit The third terminal is the second power contact of the relay.

When the switch subunit adopts a parallel topology of a plurality of MOSFETs, the first terminal of the switch subunit is a common drain of the parallel MOSFET, and the second terminal of the switch subunit is a common gate of the parallel MOSFET, the switch The third terminal of the unit is a common source stage of the parallel MOSFET; when the switch subunit adopts a parallel topology of a plurality of IGBTs, the first terminal of the switch subunit is a common collector of the parallel IGBT, and the switch subunit The second terminal is a common gate of the parallel IGBT, and the third terminal of the switch subunit is a common emitter of the parallel IGBT;

When the switch subunit adopts a parallel topology of a plurality of relays, the first terminal of the switch subunit is a common first power contact of the parallel relay, and the second terminal of the switch subunit is a total of parallel relay power coils. The control circuit, the third terminal of the switch subunit is a common second power contact of the relay.

2 is a circuit schematic diagram of an embodiment of an anti-surge bridgeless PFC circuit according to the present invention. As shown in FIG. 2, the anti-surge bridgeless PFC circuit includes: a bridgeless PFC sequentially connected between an AC power source and a load. The circuit 14 and the boosting capacitor C1; the anti-surge bridgeless PFC circuit further includes: a protection unit 11, a control unit 12, and a switch unit 13;

The protection unit 11 includes: boost diodes VD1, VD2; and, the anode of the boost diode VD1 is connected to the first output of the AC power source, the first terminal of the switch K1, and the boost inductor L1 a terminal; the cathode of the boost diode VD1 is connected to the cathode of the boost diodes VD2, VD3, VD4, the first plate of the boost capacitor C1, and is connected to the high voltage output terminal Vdc+ of the bridgeless PFC circuit 14;

The anode of the boost diode VD2 is connected to the second output of the AC power source, the first terminal of the switch K2, the first terminal of the boost inductor L2, the cathode of the boost diode VD2 is connected to the cathode of VD1, VD3, VD4, and the boost capacitor C1. a first plate connected to the high voltage output terminal Vdc+ of the bridgeless PFC circuit 14;

The boost diode VD1 is turned on only when the surge is connected to the positive half cycle of the AC power input, and the boost diode VD2 is turned on only when the surge is connected to the negative half cycle of the AC power input.

In this embodiment, the first protection sub-unit 111 and the second protection sub-unit 112 in the protection unit 11 respectively adopt the topography of the single diodes VD1 and VD2, and correspondingly, a topology in which a plurality of diodes are connected in series or in parallel may be used.

The switch unit 13 includes: a switch K1, Κ2; and, the first terminal of the switch K1 is connected to the first input of the alternating current power source, the anode of the boost diode VD1, the first terminal of the boost inductor L1; the second terminal connection control of the switch K1 The first terminal of the unit 12; the third terminal of the switch K1 is connected to the third terminal of the switch Κ2, the source of the boost switch VT1, VT2, the second plate of the boost capacitor C1, and is connected to the bridgeless PFC circuit 14 Low voltage output Vdc-;

The first terminal of the switch K2 is connected to the second input of the alternating current power source, the first terminal of the boosting inductor L2, the anode of the boosting diode VD2, and the second terminal of the switch K2 is connected to the second terminal of the control unit 12;

The switch K1 is controlled by the control unit 12, and is turned on in the negative half cycle of the AC power input; the switch K2 is controlled by the control unit 12, and is turned on in the positive half cycle of the AC power input;

When the surge is serially connected to the positive half cycle of the AC power input, the control unit 12 controls the switch K2 to be turned on to form a reflow through the boost diode VD1, the boost capacitor C1 and the switch K2 to vent the surge energy; when the surge is serialized When the AC power input is in the negative half cycle, the control unit 12 controls the switch K1 to be turned on to form a reflow through the boosting diode VD2, the boosting capacitor C1 and the switch K1, and bleed the wave. Surge energy.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

claims

1. An anti-surge bridgeless power factor correction PFC circuit, including a bridgeless PFC circuit and a boost capacitor connected in sequence between the AC power supply and the load; the anti-surge bridgeless PFC circuit also includes: a protection unit, switch unit and control unit; where,

The first terminal of the protection unit is connected to the first output of the AC power supply, the first input of the bridgeless PFC circuit, and the first terminal of the switch unit, and the second terminal of the protection unit is connected to the second output of the AC power supply. , connected to the second input of the bridgeless PFC circuit, and connected to the second terminal of the switch unit; the third terminal of the protection unit is connected to the first plate of the boost capacitor and the high-voltage output end of the bridgeless PFC circuit;

The fifth terminal of the switch unit is connected to the second plate of the boost capacitor and the low-voltage output end of the bridgeless PFC circuit;

The control unit controls the switch unit to be in a conductive state during both the positive and negative half cycles of the AC current input. When a surge enters the input of the AC power supply, the protection unit, the boost capacitor and the switch unit form a backflow and discharge the surge. energy.

2. The anti-surge bridgeless PFC circuit according to claim 1, wherein the protection unit includes: a first protection sub-unit and a second protection sub-unit;

The first terminal of the first protection subunit is connected to the first output of the AC power supply, the first input of the bridgeless PFC circuit, and the first terminal of the switch unit, and the first terminal of the second protection subunit is connected to The second output of the AC power supply is connected to the second input of the bridgeless PFC circuit and connected to the second terminal of the switch unit;

The second terminal of the first protection subunit and the second terminal of the second protection subunit are short-circuited, and connected to the first plate of the boost capacitor and the high-voltage output end of the bridgeless PFC circuit;

The first protection subunit is in conductive state only when the surge enters the positive half cycle of the AC power input. In the on state, the second protection subunit is in the on state only when a surge enters the negative half cycle of the AC power input.

3. The anti-surge bridgeless PFC circuit according to claim 2, wherein the switch unit includes a first switch subunit and a second switch subunit;

The first terminal of the first switch subunit is connected to the first output of the AC power supply and the first input of the bridgeless PFC circuit, and the first terminal of the second switch subunit is connected to the second output of the AC power supply and Connect the second input of the bridgeless PFC circuit;

The third terminal of the first switch subunit and the third terminal of the second switch subunit are short-circuited, and connected to the second plate of the boost capacitor and the low-voltage output end of the bridgeless PFC circuit;

The first switch subunit is controlled by the control unit and is in a conductive state only during the negative half cycle of the AC power input; the second switch subunit is controlled by the control unit and is in the conductive state only during the positive half cycle of the AC power input.

4. The anti-surge bridgeless PFC circuit according to claim 3, wherein,

When a surge enters the positive half cycle of the AC power input, the control unit controls the second switch subunit to turn on, and the first protection subunit, boost capacitor and second switch subunit form a backflow to discharge the surge. energy;

When a surge enters the negative half cycle of the AC power input, the control unit controls the first switch subunit to turn on, and the second protection subunit, boost capacitor and first switch subunit form a backflow to discharge the surge. energy.

5. The anti-surge bridgeless PFC circuit according to any one of claims 1 to 4, wherein the protection unit adopts a topology including a diode device.

6. The anti-surge bridgeless PFC circuit according to any one of claims 1 to 4, wherein the switch unit adopts a metal oxide semiconductor transistor MOSFET, an insulated gate bipolar transistor Body tube IGBT or relay topology.