CN108696160A - A kind of the non-bridge PFC converter and method of the low common mode interference in space - Google Patents

Abstract

The present invention proposes a method for realizing a bridgeless PFC converter with low common-mode interference for space. On the basis of a traditional bridged PFC converter, a bridgeless PFC converter is used between the anode of the second freewheeling diode D2 and the other end of the AC power supply Vac. A second winding L2 is connected in series, so that the first winding L1 and the second winding L2 form a common-mode inductance; a first capacitor C1 and a second capacitor C2 are provided, both of which are non-polar capacitors, for eliminating common-mode interference of the circuit; One end of the first capacitor C1 is connected to one end of the AC power supply Vac; one end of the second capacitor C2 is connected to the other end of the AC power supply Vac, and the other end is respectively connected to the emitter of the first switching tube S1 and the emitter of the second switching tube S2, And share the ground with the other end of the first switching capacitor C1; the energy storage capacitor C3 is a polarized capacitor for stabilizing the DC voltage at both ends. The advantages are: it can reduce the circuit loss, improve the conversion efficiency of the PFC converter, and has lower common mode interference.

Description

A bridgeless PFC converter with low common-mode interference for space and its method

technical field

The invention relates to the technical field of AC/DC conversion, in particular to a bridgeless PFC converter with low common-mode interference for space and a method thereof.

Background technique

With the increasing power demand of spacecraft, in order to reduce the quality of the power system, reduce the bus current and cable power loss, the distributed power system based on the AC bus architecture has gradually attracted people's attention.

Large harmonic interference is inevitable in the distributed power system of the AC bus structure. A large number of harmonics will not only bring great difficulties to the design of the power system, but also affect the conversion efficiency and power quality of the power system. In addition, , The space power supply system has extremely strict requirements on reliability. It is necessary to ensure that the spacecraft can complete various tasks in orbit within the design life cycle, and improve reliable technical support.

The main circuit of the PFC converter is usually composed of a DC-DC converter. Since the traditional DC-DC converter only has unipolar voltage gain, that is, the output voltage of the converter can only be the same polarity or reverse polarity with the input voltage, so It cannot be directly applied to the main circuit of the PFC converter, but a diode rectifier bridge needs to be added at the front end of the PFC converter, which leads to an increase in the conduction path loss of the PFC converter and reduces the efficiency of the PFC converter. As shown in Figure 1, the key problem of the traditional bridgeless PFC converter is that the AC side and the DC side cannot share the same ground. There is a lot of common mode interference in the structure.

Contents of the invention

The purpose of the present invention is to provide a bridgeless PFC converter with low common-mode interference for space and its method, which saves the diode rectifier, and forms a full bridge through two power MOSFET switch tubes and two fast recovery diodes, which can reduce the power consumption of the circuit. loss, improve the conversion efficiency of PFC converter, and have lower common mode interference.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

A bridgeless PFC converter with low common-mode interference for space, characterized in that it comprises:

The common mode inductor includes a first winding L1 and a second winding L2, wherein one end of the first winding L1 is connected to one end of the input AC power supply Vac, and one end of the second winding L2 is connected to the other end of the input AC power supply Vac;

The first freewheeling diode D1, the anode of which is connected to the other end of the first winding L1;

The second freewheeling diode D2, its cathode is connected to the cathode of the first freewheeling diode D1, and its anode is connected to the other end of the second winding L2;

The first switching tube S1, the collector of which is connected to the anode of the first freewheeling diode D1;

The second switching tube S2, the collector of which is connected to the anode of the second freewheeling diode D2;

The first capacitor C1 is a non-polar capacitor, which is used to eliminate the common mode interference of the circuit, and one end of it is connected to one end of the AC power supply Vac;

The second capacitor C2 is a non-polar capacitor, which is used to eliminate the common mode interference of the circuit. Its one end is connected to the other end of the AC power supply Vac, and its other end is respectively connected to the emitter of the first switch tube S1 and the emitter of the second switch tube S2. pole, and share the ground with the other end of the first switched capacitor C1;

An energy storage capacitor C3, one end of which is connected to the cathodes of the first freewheeling diode D1 and the second freewheeling diode D2 respectively, is a polarized capacitor for stabilizing the DC voltage at both ends;

The first body diode D3, its cathode is connected to the collector of the first switching tube S1, and its anode is connected to the emitter of the first switching tube S1;

The second body diode D4, its cathode is connected to the collector of the second switching tube S2, and its anode is connected to the emitter of the second switching tube S2;

The load R is connected to both ends of the energy storage capacitor C3.

The above-mentioned bridgeless PFC converter with low common mode interference for space, wherein:

When the input AC power supply Vac works in the positive half cycle, the first switch tube S1 is turned on, the second switch tube S2 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 and the second body diode D4 are reverse-biased, the current flows through the first winding L1 of the common mode inductor, the first switch tube S1, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S2 is turned off, and the current flows through the first winding L1 of the common mode inductor, the first freewheeling diode D1, the energy storage inductor C3, the load R, and the second body diode D4, the second winding L2 of the common mode inductor;

When the input AC power supply Vac works in the negative half cycle, the second switch tube S2 is turned on, the first switch tube S1 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 And the second body diode D3 is reverse biased, the current flows through the second winding L2 of the common mode inductor, the second switch tube S2, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S1 is turned off, and the current flows through the second winding L2 of the common mode inductor, the second freewheeling diode D2, the energy storage inductor C3, the load R, and the first body Diode D3, the first winding L1 of the common mode inductor.

A method for implementing a bridgeless PFC converter that reduces common-mode interference to solve the problem of common-mode interference in traditional bridged PFC converters. The traditional bridged PFC converter includes: a first winding L1, one end of which is connected to the input AC power supply Vac One end of the first freewheeling diode D1, its anode is connected to the other end of the first winding L1; the second freewheeling diode D2, its cathode is connected to the cathode of the first freewheeling diode D1, and its anode is connected to the other end of the AC power supply Vac; The collector of the first switching tube S1 is connected to the anode of the first freewheeling diode D1; the collector of the second switching tube S2 is connected to the anode of the second freewheeling diode D2; one end of the energy storage capacitor C3 is respectively connected to the anode of the second freewheeling diode D2 A freewheeling diode D1 is connected to the cathode of the second freewheeling diode D2; the cathode of the first body diode D3 is connected to the collector of the first switching tube S1, and its anode is connected to the emitter of the first switching tube S1 and grounded at the same time; Two-body diode D4, its cathode is connected to the collector of the second switching tube S2, and its anode is connected to the emitter of the second switching tube S2; the load R is connected to the two ends of the energy storage capacitor C3; it is characterized in that the traditional bridge The circuit of the PFC converter is changed to a bridgeless type, specifically:

A second winding L2 is connected in series between the anode of the second freewheeling diode D2 and the other end of the AC power supply Vac, so that the first winding L1 and the second winding L2 form a common mode inductance;

Set a first capacitor C1 and a second capacitor C2, both of which are non-polar capacitors, and are used to eliminate common mode interference of the circuit; one end of the first capacitor C1 is connected to one end of the AC power supply Vac; one end of the second capacitor C2 is connected to the AC power supply Vac The other end of which is connected to the emitter of the first switching tube S1 and the emitter of the second switching tube S2 respectively, and is shared with the other end of the first switching capacitor C1;

The energy storage capacitor C3 is a polarized capacitor for stabilizing the DC voltage at both ends.

The implementation method of the above-mentioned bridgeless PFC converter for reducing common-mode interference, wherein:

When the input AC power supply Vac works in the positive half cycle, the first switch tube S1 is turned on, the second switch tube S2 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 and the second body diode D4 are reverse-biased, the current flows through the first winding L1 of the common mode inductor, the first switch tube S1, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S2 is turned off, and the current flows through the first winding L1 of the common mode inductor, the first freewheeling diode D1, the energy storage inductor C3, the load R, and the second body diode D4, the second winding L2 of the common mode inductor;

When the input AC power supply Vac works in the negative half cycle, the second switch tube S2 is turned on, the first switch tube S1 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 And the second body diode D3 is reverse biased, the current flows through the second winding L2 of the common mode inductor, the second switch tube S2, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S1 is turned off, and the current flows through the second winding L2 of the common mode inductor, the second freewheeling diode D2, the energy storage inductor C3, the load R, and the first body Diode D3, the first winding L1 of the common mode inductor.

Compared with the prior art, the invention has the following advantages: the circuit loss can be reduced, the conversion efficiency of the PFC converter can be improved, and the common mode interference is lower.

Description of drawings

Fig. 1 is the circuit diagram of bridged PFC converter of prior art;

Fig. 2 is the circuit diagram of bridgeless PFC converter of the present invention;

Fig. 3 is the working schematic diagram when the present invention works in the positive half cycle, the switch tube S1 is turned on, and the switch tube S2 is turned off;

Fig. 4 is the working schematic diagram when the present invention works in the positive half cycle, when the switching tube S1 and the switching tube S2 are all turned off;

Fig. 5 is the working diagram when the present invention works in the negative half cycle, the switch tube S1 is turned off, and the switch tube S2 is turned on;

FIG. 6 is a working schematic diagram of the present invention when the switching tube S1 and the switching tube S2 are both turned off in the negative half cycle.

Detailed ways

The present invention will be further elaborated below by describing a preferred specific embodiment in detail in conjunction with the accompanying drawings.

As shown in Figure 2, the present invention discloses a bridgeless PFC converter with low common-mode interference for space, which includes: a common-mode inductor, including a first winding L1 and a second winding L2, wherein one end of the first winding L1 is connected to One end of the input AC power Vac, one end of the second winding L2 is connected to the other end of the input AC power Vac; the first freewheeling diode D1, its anode is connected to the other end of the first winding L1; the second freewheeling diode D2, its cathode is connected to the second freewheeling diode D2 The cathode of a freewheeling diode D1, its anode is connected to the other end of the second winding L2; the collector of the first switching tube S1 is connected to the anode of the first freewheeling diode D1; the collector of the second switching tube S2 is connected to the second end of the second winding L2 The anode of the freewheeling diode D2 is connected; the first capacitor C1 is a non-polar capacitor, which is used to eliminate the common mode interference of the circuit, and one end of it is connected to one end of the AC power supply Vac; the second capacitor C2 is a non-polar capacitor, which is used to eliminate Common mode interference of the circuit, one end of which is connected to the other end of the AC power supply Vac, and the other end is respectively connected to the emitter of the first switching tube S1 and the emitter of the second switching tube S2, and is shared with the other end of the first switching capacitor C1 Ground; energy storage capacitor C3, one end of which is respectively connected to the cathodes of the first freewheeling diode D1 and the second freewheeling diode D2, which is a polarized capacitor used to stabilize the DC voltage at both ends; the first body diode D3, Its cathode is connected to the collector of the first switching tube S1, its anode is connected to the emitter of the first switching tube S1; the second body diode D4, its cathode is connected to the collector of the second switching tube S2, and its anode is connected to the second switching tube S2 The emitter; load R, connected to both ends of the energy storage capacitor C3.

The mechanism of the above topological transformation is:

As shown in Figure 3, when the input AC power supply Vac works in the positive half cycle, the first switch tube S1 is turned on, the second switch tube S2 is turned off, and the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased , the first body diode D3 and the second body diode D4 are reverse biased, the current flows through the first winding L1 of the common mode inductor, the first switch tube S1, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 is discharged Provide the required energy for the load R; as shown in Figure 4, when the first switching tube S1 is turned off, the second switching tube S2 is turned off, and the current flows through the first winding L1 of the common mode inductor, the first freewheeling diode D1, The energy storage inductor C3, the load R, the second body diode D4, and the second winding L2 of the common mode inductor.

As shown in Figure 5, when the input AC power supply Vac works in the negative half cycle, the second switch tube S2 is turned on, the first switch tube S1 is turned off, and the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased , the first body diode D3 and the second body diode D3 are reverse biased, the current flows through the second winding L2 of the common mode inductor, the second switch tube S2, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 is discharged Provide the required energy for the load R; as shown in Figure 6, when the first switch tube S1 is turned off, the second switch tube S1 is turned off, and the current flows through the second winding L2 of the common mode inductor and the second freewheeling diode D2 , an energy storage inductor C3, a load R, a first body diode D3, and a first winding L1 of a common mode inductor.

The structure of the bridgeless PFC converter circuit proposed by the present invention is simple, only two freewheeling diodes D1, D2, two power switch tubes S1, S2 and a common mode inductor L1, L2 are used, and the circuit works in positive half cycle and negative In the half-cycle mode, each half-cycle can be regarded as a Boost circuit. In addition, the bridgeless PFC converter uses fewer power devices than the traditional topology, saves the rectifier bridge, greatly reduces the loss, and improves the conversion and transmission efficiency of the whole machine. The above-mentioned bridgeless PFC converter also has a good common-mode interference suppression effect. Compared with the traditional bridgeless Boost PFC circuit, a capacitor is added between both sides of the input AC voltage source and the power ground, so that the power ground and the input A high-frequency circuit channel is added between the power supplies to weaken common-mode interference.

The present invention also proposes an implementation method of a bridgeless PFC converter that reduces common-mode interference, so as to solve the problem of common-mode interference in traditional bridged PFC converters. The traditional bridged PFC converter includes: a first winding L1, one end Connect one end of the input AC power supply Vac; the first freewheeling diode D1, its anode is connected to the other end of the first winding L1; the second freewheeling diode D2, its cathode is connected to the cathode of the first freewheeling diode D1, and its anode is connected to the AC power supply The other end of Vac; the first switching tube S1, whose collector is connected to the anode of the first freewheeling diode D1; the second switching tube S2, whose collector is connected to the anode of the second freewheeling diode D2; the energy storage capacitor C3, One end thereof is respectively connected to the cathodes of the first freewheeling diode D1 and the second freewheeling diode D2; the cathode of the first body diode D3 is connected to the collector of the first switching tube S1, and its anode is connected to the emitter of the first switching tube S1 and ground simultaneously; the second body diode D4, its cathode connected to the collector of the second switching tube S2, and its anode connected to the emitter of the second switching tube S2; the load R is connected to both ends of the energy storage capacitor C3; it is characterized in that , the circuit of the traditional bridged PFC converter is changed into a bridgeless type, specifically: a second winding L2 is connected in series between the anode of the second freewheeling diode D2 and the other end of the AC power supply Vac, so that the first winding L1 and The second winding L2 forms a common-mode inductance; a first capacitor C1 and a second capacitor C2 are provided, both of which are non-polar capacitors, and are used to eliminate common-mode interference of the circuit; one end of the first capacitor C1 is connected to one end of the AC power supply Vac; One end of the second capacitor C2 is connected to the other end of the AC power supply Vac, and the other end is respectively connected to the emitter of the first switching tube S1 and the emitter of the second switching tube S2, and shares the ground with the other end of the first switching capacitor C1; Capacitor C3 is a polarized capacitor for stabilizing the DC voltage at both ends.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims (4)

1. A bridgeless PFC converter with low common-mode interference for space, characterized in that it comprises: The common mode inductor includes a first winding L1 and a second winding L2, wherein one end of the first winding L1 is connected to one end of the input AC power supply Vac, and one end of the second winding L2 is connected to the other end of the input AC power supply Vac; The first freewheeling diode D1, the anode of which is connected to the other end of the first winding L1; The second freewheeling diode D2, its cathode is connected to the cathode of the first freewheeling diode D1, and its anode is connected to the other end of the second winding L2; The first switching tube S1, the collector of which is connected to the anode of the first freewheeling diode D1; The second switching tube S2, the collector of which is connected to the anode of the second freewheeling diode D2; The first capacitor C1 is a non-polar capacitor, which is used to eliminate the common mode interference of the circuit, and one end of it is connected to one end of the AC power supply Vac; The second capacitor C2 is a non-polar capacitor, which is used to eliminate the common mode interference of the circuit. Its one end is connected to the other end of the AC power supply Vac, and its other end is respectively connected to the emitter of the first switch tube S1 and the emitter of the second switch tube S2. pole, and share the ground with the other end of the first switched capacitor C1; An energy storage capacitor C3, one end of which is connected to the cathodes of the first freewheeling diode D1 and the second freewheeling diode D2 respectively, is a polarized capacitor for stabilizing the DC voltage at both ends; The first body diode D3, its cathode is connected to the collector of the first switching tube S1, and its anode is connected to the emitter of the first switching tube S1; The second body diode D4, its cathode is connected to the collector of the second switching tube S2, and its anode is connected to the emitter of the second switching tube S2; The load R is connected to both ends of the energy storage capacitor C3. 2. the bridgeless PFC converter of low common mode interference for space as claimed in claim 1, is characterized in that: When the input AC power supply Vac works in the positive half cycle, the first switch tube S1 is turned on, the second switch tube S2 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 and the second body diode D4 are reverse-biased, the current flows through the first winding L1 of the common mode inductor, the first switch tube S1, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S2 is turned off, and the current flows through the first winding L1 of the common mode inductor, the first freewheeling diode D1, the energy storage inductor C3, the load R, and the second body diode D4, the second winding L2 of the common mode inductor; When the input AC power supply Vac works in the negative half cycle, the second switch tube S2 is turned on, the first switch tube S1 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 And the second body diode D3 is reverse biased, the current flows through the second winding L2 of the common mode inductor, the second switch tube S2, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S1 is turned off, and the current flows through the second winding L2 of the common mode inductor, the second freewheeling diode D2, the energy storage inductor C3, the load R, and the first body Diode D3, the first winding L1 of the common mode inductor. 3. An implementation method of a bridgeless PFC converter that reduces common-mode interference, to solve the problem of common-mode interference in traditional bridged PFC converters. Traditional bridged PFC converters include: the first winding L1, one end connected to the input AC One end of the power supply Vac; the first freewheeling diode D1, whose anode is connected to the other end of the first winding L1; the second freewheeling diode D2, whose cathode is connected to the cathode of the first freewheeling diode D1, and whose anode is connected to the other end of the AC power supply Vac One end; the first switching tube S1, whose collector is connected to the anode of the first freewheeling diode D1; the second switching tube S2, whose collector is connected to the anode of the second freewheeling diode D2; energy storage capacitor C3, one end of which is respectively It is connected to the cathodes of the first freewheeling diode D1 and the second freewheeling diode D2; the first body diode D3, its cathode is connected to the collector of the first switching tube S1, and its anode is connected to the emitter of the first switching tube S1 and grounded at the same time ; The second body diode D4, its cathode is connected to the collector of the second switching tube S2, and its anode is connected to the emitter of the second switching tube S2; the load R is connected to the two ends of the energy storage capacitor C3; it is characterized in that the traditional The circuit of the bridge PFC converter is changed to a bridgeless type, specifically: A second winding L2 is connected in series between the anode of the second freewheeling diode D2 and the other end of the AC power supply Vac, so that the first winding L1 and the second winding L2 form a common mode inductance; Set a first capacitor C1 and a second capacitor C2, both of which are non-polar capacitors, and are used to eliminate common mode interference of the circuit; one end of the first capacitor C1 is connected to one end of the AC power supply Vac; one end of the second capacitor C2 is connected to the AC power supply Vac The other end of which is connected to the emitter of the first switching tube S1 and the emitter of the second switching tube S2 respectively, and is shared with the other end of the first switching capacitor C1; The energy storage capacitor C3 is a polarized capacitor for stabilizing the DC voltage at both ends. 4. the realization method of the bridgeless PFC converter that reduces common-mode interference as claimed in claim 3 is characterized in that: When the input AC power supply Vac works in the positive half cycle, the first switch tube S1 is turned on, the second switch tube S2 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 and the second body diode D4 are reverse-biased, the current flows through the first winding L1 of the common mode inductor, the first switch tube S1, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S2 is turned off, and the current flows through the first winding L1 of the common mode inductor, the first freewheeling diode D1, the energy storage inductor C3, the load R, and the second body diode D4, the second winding L2 of the common mode inductor; When the input AC power supply Vac works in the negative half cycle, the second switch tube S2 is turned on, the first switch tube S1 is turned off, the first freewheeling diode D1 and the second freewheeling diode D2 are reverse biased, and the first body diode D3 And the second body diode D3 is reverse biased, the current flows through the second winding L2 of the common mode inductor, the second switch tube S2, the first capacitor C1 and the second capacitor C2, and the energy storage capacitor C3 discharges to provide the load R with the required energy; when the first switching tube S1 is turned off, the second switching tube S1 is turned off, and the current flows through the second winding L2 of the common mode inductor, the second freewheeling diode D2, the energy storage inductor C3, the load R, and the first body Diode D3, the first winding L1 of the common mode inductor.