AC / DC input power supply circuit and switching power supply

Abstract

The utility model discloses an AC / DC input power supply circuit and a switching power supply. The AC / DC input power supply circuit comprises a controllable rectification circuit, a BUCK slow charging circuit, a BOOST power factor correction circuit, a first input end, a second input end, a first output end and a second output end. The controllable rectifying circuit comprises a diode D2, a diode D3, a controllable switch V1 and a controllable switch V2; the BOOST power factor correction circuit comprises an inductor L1, an MOS tube S2, a diode D6 and an output capacitor C1. The BUCK slow charging circuit comprises a diode D1, an MOS tube S1, a diode D2, a diode D3 and an inductor L1. According to the utility model, the controllable rectification circuit and the BUCK slow charging circuit multiplex diodes D2 and D3, and the BUCK slow charging circuit and the BOOST power factor correction circuit multiplex inductor L1, so that on the basis of compatibility of AC / DC input, effective suppression of starting surge current and realization of steady-state power factor correction, high multiplexing of power devices is realized, the circuit size is reduced, the device cost is optimized, and the power factor correction circuit is suitable for popularization and application. And the overall loss is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of power electronics technology, and specifically relates to an AC / DC input power supply circuit and a switching power supply. Background Technology

[0002] In AC / DC input switching power supplies, it is usually necessary to simultaneously satisfy the functions of AC / DC compatible rectification, startup surge current suppression, and power factor correction. Conventional technical solutions use ordinary rectifier bridge circuits, power resistors and switch parallel circuits, and power factor correction circuits to achieve the above functions, which have problems such as large circuit size, low efficiency, unstable startup surge current, high component cost, and lack of support for fast and frequent power-on and power-off. Utility Model Content

[0003] Therefore, the technical problem to be solved by this utility model is to provide an AC / DC input power supply circuit and a switching power supply. By highly reusing components, it can achieve AC / DC compatible rectification, inrush current suppression, and power factor correction functions, while also reducing circuit size, optimizing component costs, and reducing circuit losses.

[0004] As the first aspect of this utility model, the technical solution of the provided AC / DC input power supply circuit is as follows:

[0005] An AC / DC input power supply circuit includes: a controllable rectifier circuit, a BUCK soft charging circuit, a BOOST power factor correction circuit, a first input terminal, a second input terminal, a first output terminal, and a second output terminal; the controllable rectifier circuit includes diodes D2 and D3, a controllable switch V1, and a controllable switch V2; the BOOST power factor correction circuit includes an inductor L1, a MOSFET S2, a diode D6, and an output capacitor C1; the BUCK soft charging circuit includes diode D1, a MOSFET S1, diode D2, diode D3, and inductor L1; the anode of diode D2 and the cathode of diode D3 are connected together as the first input terminal, and the anode of diode D1, the cathode of diode D3, and the cathode of diode D3 are connected together as the first input terminal, and the cathode of diode D1, the cathode of diode D3, and the cathode of diode D4 are connected together as the first input terminal, and the cathode of diode D5, the cathode of diode D6, and the cathode of diode D7 are connected together as the first input terminal, and the cathode of diode D6, the cathode of diode D7, and the cathode of diode D8 are connected together as the first input terminal, and the cathode of diode D1, the cathode of diode D3, and the cathode of diode D6 are connected together as the first input terminal, and the cathode of diode D7, the cathode of diode D8, and the cathode of diode D9 are connected together as the first input terminal, and the cathode of diode D1, the cathode of diode D2, and the cathode of diode D3 ...6, the cathode of diode D7, and the cathode of diode D8, the cathode of diode D9, and the cathode of diode D1 are connected together as the first input terminal, and the cathode of One end of the controllable switch V1 and one end of the controllable switch V2 are connected together as the second input terminal; the cathode of the diode D1 is connected to the drain of the MOSFET S1; the cathode of the diode D2, the other end of the controllable switch V1, and the source of the MOSFET S1 are connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the drain of the MOSFET S2 and the anode of the diode D6; the positive terminal of the output capacitor C1 is connected to the cathode of the diode D6 as the first output terminal, and the negative terminal of the output capacitor C1, the anode of the diode D3, the other end of the controllable switch V2, and the source of the MOSFET S2 are connected together as the second output terminal.

[0006] Furthermore, when the AC / DC input power supply circuit is a DC input, the second input terminal is the positive input terminal and the first input terminal is the negative input terminal.

[0007] Preferably, the controllable switch V1 is a first thyristor, one end of the controllable switch V1 is the anode of the first thyristor, and the other end of the controllable switch V1 is the cathode of the first thyristor; the controllable switch V2 is a second thyristor, one end of the controllable switch V2 is the cathode of the second thyristor, and the other end of the controllable switch V2 is the anode of the second thyristor.

[0008] Furthermore, the AC / DC input power supply circuit also includes a controllable switch V3. One end of the controllable switch V3 is connected to the connection point between the cathode of the diode D2 and the source of the MOSFET S1, and the other end of the controllable switch V3 is connected to the connection point between the positive terminal of the output capacitor C1 and the cathode of the diode D6.

[0009] Preferably, the controllable switch V3 is a third thyristor, one end of the controllable switch V3 is the anode of the third thyristor, and the other end of the controllable switch V3 is the cathode of the third thyristor.

[0010] As a second aspect of this utility model, the technical solution of the provided switching power supply embodiment is as follows:

[0011] A switching power supply, wherein: it includes the AC / DC input power supply circuit described in any of the first aspects above.

[0012] When the AC / DC input power supply circuit and the switching power supply input terminal of this utility model are connected to AC and DC power supplies, the BUCK soft charging circuit pre-charges the output capacitor C1. After the pre-charging is completed, the controllable rectifier circuit and the BOOST power factor correction circuit start working, completing the startup process and entering a steady state. The controllable rectifier circuit and the BUCK soft charging circuit share diodes D2 and D3, and the BUCK soft charging circuit and the BOOST power factor correction circuit share inductor L1. The beneficial effects of this utility model compared to the prior art are as follows:

[0013] The AC / DC input power supply circuit and switching power supply of this utility model not only achieve functions such as AC / DC input rectification, surge current suppression, and power factor correction, but also reduce the number of components, effectively reduce the circuit size, optimize component costs, and reduce overall losses through high component reuse. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of an AC / DC input power supply circuit of this utility model;

[0015] Figure 2 In order to be in Figure 1 The circuit diagram is based on the addition of a bypass controllable switch. Detailed Implementation

[0016] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0017] It should be noted that the terms "comprising" and "having" and any variations thereof described in the specification and claims of this application are intended to cover non-exclusive inclusion. For example, including a series of components, unit circuits or control timings is not necessarily limited to those components, unit circuits or control timings that are explicitly listed, but may include components, unit circuits or control timings that are not explicitly listed or that are inherent to these circuits.

[0018] Furthermore, unless otherwise specified, the embodiments and features described in this application may be combined with each other.

[0019] It should be understood that, in the specification and claims, when an element is described as being "connected" to another element, that element may be "directly connected" to that other element or "connected" to that other element through a third element; when a step is described as being connected to another step, that step may be connected directly to that other step or connected to that other step through a third step.

[0020] Figure 1 This is a schematic diagram of an AC / DC input power supply circuit according to this utility model, including a first input terminal, a second input terminal, a first output terminal, a second output terminal, a controllable rectifier circuit, a BUCK soft charging circuit, and a BOOST power factor correction circuit. Please refer to [link / reference]. Figure 1The controllable rectifier circuit includes rectifier diodes D2 and D3, controllable switch V1 and controllable switch V2; the BOOST power factor correction circuit includes inductor L1, MOSFET S2 and diode D6; the BUCK soft charging circuit includes rectifier diode D1, MOSFET S1, diodes D2 and D3 multiplexed with the controllable rectifier circuit, and inductor L1 multiplexed with the BOOST power factor correction circuit. The first input terminal is connected to the anode of rectifier diode D2 and the cathode of diode D3. The second input terminal is connected to the anode of controllable switch V1 and the cathode of controllable switch V2. The anode of diode D1 is connected to the anode of controllable switch V1, and the cathode of diode D1 is connected to the drain of MOSFET S1. The cathodes of diode D2, controllable switch V1, and the source of MOSFET S1 are connected to the drain of MOSFET S2 and the anode of diode D6 through inductor L1. The positive terminal of output capacitor C1 is connected to the cathode of diode D6 and to the first output terminal. The negative terminal of output capacitor C1 is connected to the anode of diode D3, the anode of controllable switch V2, and the source of MOSFET S2 and to the second output terminal.

[0021] In practice, the power input to the first input terminal and the second input terminal can be either AC power or DC power. When it is DC power, the positive terminal of the DC power supply is connected to the second input terminal connected to the rectifier diode D1, and the negative terminal of the DC power supply is connected to the first input terminal.

[0022] In practical implementation, controllable switches V1 and V2 are Figure 1 The thyristor shown can also be a type of controlled rectifier bridge composed of other controllable switching devices.

[0023] The following combination Figure 1 The working principle of the AC / DC input power supply circuit of this utility model is analyzed as follows:

[0024] When the first and second input terminals are connected to AC power, controllable switches V1 and V2 are not open, and the BUCK slow-charging circuit starts working. First, it drives MOSFET S1 to conduct, forming a BUCK magnetizing circuit consisting of diode D1, MOSFET S1, inductor L1, diode D6, output capacitor C1, and diode D3. When MOSFET S1 is turned off, a BUCK demagnetizing freewheeling circuit consists of inductor L1, diode D6, output capacitor C1, diode D3, and diode D2, slowly charging output capacitor C1 during the half-wave of the AC input. When the voltage of output capacitor C1 reaches the pre-charge target value, the controllable rectifier circuit turns on. When the circuit starts working, the controllable rectifier circuit contains two controllable switches V1 and V2 and two rectifier diodes D2 and D3. Controllable switches V1 and V2 are unidirectionally turned on, simulating the operation of a full-wave rectifier bridge. After the controllable rectifier circuit starts working, the BOOST power factor correction circuit works. First, it drives the MOSFET S2 to conduct, and the inductor L1 and the MOSFET S2 form the BOOST excitation circuit. When the MOSFET S2 is turned off, the inductor L1, the diode D6, and the output capacitor C1 form the BOOST demagnetization freewheeling circuit. The AC / DC input power supply circuit completes the startup process and enters a steady state. The BOOST circuit realizes the power factor correction function.

[0025] When the first and second input terminals are connected to a DC power supply, the positive terminal of the DC input power supply must be connected to... Figure 1 N-terminal and negative terminal connection Figure 1 With controllable switches V1 and V2 closed at terminal L, the BUCK slow-charging circuit begins operation. It first drives MOSFET S1 to conduct, forming a BUCK magnetizing circuit consisting of diode D1, MOSFET S1, inductor L1, diode D6, output capacitor C1, and diode D3. When MOSFET S1 is turned off, a BUCK demagnetizing freewheeling circuit is formed by inductor L1, diode D6, output capacitor C1, diode D3, and diode D2, slowly charging output capacitor C1. Once the voltage across output capacitor C1 is approximately equal to the input DC power supply voltage, the BUCK slow-charging circuit stops operating, and the controllable rectifier circuit opens. Upon initial operation, the controllable rectifier circuit, consisting of two controllable switches V1 and V2 and two rectifier diodes D2 and D3, operates unidirectionally. The input DC power supply forms a loop through the controllable switch V1 and diode D3. After the controllable rectifier circuit starts operating, the BOOST power factor correction circuit operates, first driving MOSFET S2 to conduct. The BOOST excitation loop is formed by inductor L1 and MOSFET S2. When MOSFET S2 is turned off, the BOOST demagnetization freewheeling loop is formed by inductor L1, diode D6, and output capacitor C1. The AC / DC input power supply circuit completes the startup process and enters a steady state.

[0026] Figure 2 In order to be in Figure 1 Based on this, add a bypass controllable switch to the circuit diagram, such as... Figure 2As shown, the AC / DC input power supply circuit also includes a controllable switch V3. One end of the controllable switch V3 is connected to the junction of the cathode of diode D2 and the source of MOSFET S1, and the other end of the controllable switch V3 is connected to the junction of the positive terminal of output capacitor C1 and the cathode of diode D6. In specific implementation, the bypass controllable switch V3 is a thyristor or other controllable switch. The control requirements for the controllable switch V3 are: when a lightning surge voltage is detected, it is turned on, and the lightning surge current is absorbed by the output capacitor C1 through the controllable switch V3; when no lightning surge voltage is detected, it is turned off. Figure 1 The circuit works normally, and the addition of controllable switch V3 can further improve the circuit's surge current resistance. Other connection methods and control principles are the same as in the previous embodiment, and will not be described again here.

[0027] This utility model also provides a switching power supply, including any of the above-mentioned AC / DC input power supply circuits.

[0028] The above description of the embodiments is only for the purpose of helping to understand the inventive concept of this utility model, and is not intended to limit this utility model. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc., made without departing from the principle of this utility model should be included within the protection scope of this utility model.

Claims

1. An AC / DC input power supply circuit, characterized in that: The circuit includes a controllable rectifier circuit, a BUCK soft-charge circuit, a BOOST power factor correction circuit, a first input terminal, a second input terminal, a first output terminal, and a second output terminal. The controllable rectifier circuit includes diodes D2 and D3, a controllable switch V1, and a controllable switch V2. The BOOST power factor correction circuit includes an inductor L1, a MOSFET S2, a diode D6, and an output capacitor C1. The BUCK soft-charge circuit includes diode D1, a MOSFET S1, diodes D2 and D3, and the inductor L1. The anode of diode D2 and the cathode of diode D3 are connected together as the first input terminal. The anode of diode D1 and the cathode of the controllable switch V1 are connected together as the first input terminal. One end of the controllable switch V2 is connected to one end of the controllable switch V2 as the second input terminal; the cathode of the diode D1 is connected to the drain of the MOSFET S1; the cathode of the diode D2, the other end of the controllable switch V1, and the source of the MOSFET S1 are connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the drain of the MOSFET S2 and the anode of the diode D6; the positive terminal of the output capacitor C1 is connected to the cathode of the diode D6 as the first output terminal, and the negative terminal of the output capacitor C1, the anode of the diode D3, the other end of the controllable switch V2, and the source of the MOSFET S2 are connected together as the second output terminal.

2. The AC / DC input power supply circuit according to claim 1, characterized in that: When the AC / DC input power supply circuit is a DC input, the second input terminal is the positive input terminal and the first input terminal is the negative input terminal.

3. The AC / DC input power supply circuit according to claim 1, characterized in that: The controllable switch V1 is a first thyristor, one end of the controllable switch V1 is the anode of the first thyristor, and the other end of the controllable switch V1 is the cathode of the first thyristor; The controllable switch V2 is a second thyristor, one end of the controllable switch V2 is the cathode of the second thyristor, and the other end of the controllable switch V2 is the anode of the second thyristor.

4. The AC / DC input power supply circuit according to claim 1, characterized in that: The AC / DC input power supply circuit also includes a controllable switch V3. One end of the controllable switch V3 is connected to the connection point between the cathode of the diode D2 and the source of the MOS transistor S1, and the other end of the controllable switch V3 is connected to the connection point between the positive terminal of the output capacitor C1 and the cathode of the diode D6.

5. The AC / DC input power supply circuit according to claim 4, characterized in that: The controllable switch V3 is a third thyristor, one end of the controllable switch V3 is the anode of the third thyristor, and the other end of the controllable switch V3 is the cathode of the third thyristor.

6. A switching power supply, characterized in that: Includes the AC / DC input power supply circuit as described in any one of claims 1 to 5.

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