A bipolar self-equalizing center-tapped rectifier circuit

Abstract

A bipolar self-equalizing center-tapped rectifier circuit, the circuit comprising: a three-winding center-tapped rectifier circuit, two equalizing capacitors; the three-winding center-tapped rectifier circuit comprises an input source u s , three-winding transformer T, rectifier diode D P1 , rectifier diode D P2 , rectifier diode D N1 , rectifier diode D N2 , output capacitor C P , output capacitor C N The voltage balancing capacitor includes a voltage balancing capacitor C VB1 And voltage balancing capacitor C VB2 The present invention discloses a bipolar self-equalizing center-tapped rectifier circuit, which can effectively reduce the problem of large deviation in output voltage of the bipolar center-tapped rectifier circuit when the load is unbalanced, and can realize automatic voltage equalization of bipolar output only through voltage equalization capacitors, without complex sampling and control algorithms, and is suitable for occasions requiring bipolar voltage power supply.

Description

Technical Field

[0001] The invention relates to a center-tapped rectifier circuit, in particular to a bipolar self-equalizing center-tapped rectifier circuit. Background Art

[0002] In the prior art, the center-tapped rectifier circuit has a much higher rectification efficiency than the half-wave rectifier circuit and is widely used in power equipment. Among them, the bipolar center-tapped rectifier circuit can achieve that when one of the outputs fails, the other can work normally; and when it is operating normally, it can provide three voltage levels. Due to its high flexibility and reliability, the bipolar circuit has inherent advantages in the fields of new energy such as photovoltaics and fuel cells, and in the power supply of data centers and computer rooms. Therefore, the bipolar circuit is widely used in data centers and DC microgrids. However, the bipolar circuit based on the transformer multi-output winding design has the problem of cross-regulation rate, which will cause a large voltage deviation between the positive and negative poles when the load is unbalanced, affecting the power quality of the load equipment, and even causing the system to fail to work properly in severe cases.

[0003] At present, in order to realize the two-stage voltage balancing of the bipolar circuit, the improvement measures are mainly divided into two aspects: control and circuit topology. For example, the patent with application publication number CN106026667A discloses a method for improving the cross-regulation rate of a multi-channel output switching power supply. The converter described in the patent places the RCD absorption circuit on the secondary output winding side to directly absorb and suppress the leakage inductance voltage spike of the secondary output winding. At the same time, combined with the effect of the primary side clamping circuit, the leakage inductance voltage spike and leakage inductance energy coupling in the transformer can be further reduced, the stability of the auxiliary output voltage can be improved, and the cross-regulation rate of the multi-channel output switching power supply can be improved. However, the additional RCD circuit on the secondary side will consume part of the energy in the circuit, making the transmission efficiency of the converter low.

[0004] The patent document with the authorization announcement number CN209030069U discloses a multi-channel output power supply. The power module adds a timing control circuit composed of a control module, a drive module, an isolation module and a detection module to the auxiliary output circuit, which can independently control the output voltage of each circuit, greatly reducing the cost, while ensuring the isolation between the outputs, and improving the power supply reliability of the power module. However, setting a timing control circuit for each output circuit will increase the control difficulty, especially for a multi-channel output power module. Summary of the invention

[0005] In order to solve the problem that the positive and negative output voltages of a bipolar center-tapped rectifier circuit are easily affected by load disturbances and produce deviations, the present invention proposes a bipolar self-equalizing center-tapped rectifier circuit, which can effectively reduce the problem of large deviations in the output voltage of the bipolar center-tapped rectifier circuit when the load is unbalanced, and automatic voltage equalization of the bipolar output can be achieved only through voltage equalization capacitors, without the need for complex sampling and control algorithms, and is suitable for occasions requiring bipolar voltage power supply.

[0006] The technical solution adopted by the present invention is:

[0007] A bipolar self-equalizing center-tapped rectifier circuit, the circuit comprising: a three-winding center-tapped rectifier circuit, two equalizing capacitors;

[0008] The three-winding center-tapped rectifier circuit includes an input source u s , three-winding transformer T, rectifier diode D P1 , rectifier diode D P2 , rectifier diode D N1 , rectifier diode D N2 , output capacitor C P , output capacitor C N , its connection form is as follows:

[0009] Input power s One end of the three-winding transformer T is connected to the primary winding L p One end, input power u s The other end is connected to the primary winding L of the three-winding transformer T p The other end;

[0010] The secondary winding L of the three-winding transformer T S1 Including winding unit L S1-1 and winding unit winding L S1-2 , winding unit L S1-1 One end and the rectifier diode D P1 Anode connection, winding unit L S1-2 The other end is connected to the rectifier diode D P2 Anode connection;

[0011] Winding unit L S1-1 The other end of the winding unit L S1-2 One end of the output capacitor C is connected to form a first center tap. P The other end is connected;

[0012] The secondary winding L of the three-winding transformer T S2 Including winding unit L S2-1 and winding unit L S2-2 , winding unit L S2-1One end and the rectifier diode D N1 Anode connection, winding unit L S2-2 The other end is connected to the rectifier diode D N2 Anode connection;

[0013] Winding unit L S2-1 The other end of the winding unit L S2-2 The second center tap is connected to the output capacitor C N The other end is connected;

[0014] Rectifier diode D P1 The cathodes of the rectifier diodes D P2 The cathode of the output capacitor C P One end

[0015] Rectifier diode D N1 The cathodes of the diodes D N2 The cathode of the output capacitor C N one end of

[0016] Output capacitor C P The other end of the output capacitor C N one end of

[0017] The voltage grading capacitor includes a voltage grading capacitor C VB1 And the voltage balancing capacitor C VB2 , its connection form is as follows:

[0018] Voltage balancing capacitor C VB1 One end of the three-winding transformer T is connected to the secondary winding L S1 One end, voltage balancing capacitor C VB1 The other end is connected to the secondary winding L of the three-winding transformer T S2 one end;

[0019] Voltage balancing capacitor C VB2 One end of the three-winding transformer T is connected to the secondary winding L S1 The other end, the voltage balancing capacitor C VB2 The other end is connected to the secondary winding L of the three-winding transformer T S2 The other end;

[0020] Load R P The two ends of the output capacitor C P One end of the output capacitor C P The other end of the load R N The two ends of the output capacitor C N One end of the output capacitor C N the other end.

[0021] The current is carried by the primary winding L of the three-winding transformer T p When one end flows into the rectifier diode D P1 and rectifier diode D N1 Conductivity;

[0022] The current is carried by the primary winding L of the three-winding transformer T p When the other end flows into the rectifier diode D P2 and rectifier diode D N2 Conductivity.

[0023] During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1 and L s2 The average voltage is 0, and C VB1 →L s1 →C VB2 →L s2 →C VB1 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB1 The voltage u CVB1 Equal to the voltage balancing capacitor C VB2 The voltage u CVB2 .

[0024] During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1-1 and L s2-1 The average voltage is 0, and the VB1 →L s1-1 →C N →L s2-1 →C VB1 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB1 The voltage u CVB1 Equal to the output capacitance C N The voltage u CN .

[0025] During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1-2 and L s2-2 The average voltage is 0, and the VB2 →L s1-2 →C N →L s2-2 →C VB2 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB2 The voltage u CVB2 Equal to the output capacitance C N The voltage u CN .

[0026] When the current flows through the primary winding L of the three-winding transformer T p When one end flows into the rectifier diode D P1and rectifier diode D N1 Conducting, voltage balancing capacitor C VB1 Through the rectifier diode D P1 and rectifier diode D N1 With output capacitor C P In parallel, there is an output capacitor C P The voltage u CP Equal to u CVB1 ; Voltage balancing capacitor C VB2 Through the transformer secondary coil L s1 , L s2 and rectifier diode D P1 , rectifier diode D N1 With output capacitor C P In parallel, due to the transformer secondary coil L s1 and L s2 The number of turns is equal, so there is an output capacitor C P The voltage u CP Equal to u CVB2 ;

[0027] When the current flows through the primary winding L of the three-winding transformer T p When the other end flows into the rectifier diode D P2 and rectifier diode D N2 Conducting, voltage balancing capacitor C VB2 Through the rectifier diode D P2 and rectifier diode D N2 With output capacitor C P In parallel, there is an output capacitor C P The voltage u CP Equal to u CVB2 ; Voltage balancing capacitor C VB1 Through the transformer secondary coil L s1 , L s2 and rectifier diode D P2 , rectifier diode D N2 With output capacitor C P In parallel, due to the transformer secondary coil L s1 and L s2 The number of turns is equal, so there is an output capacitor C P The voltage u CP Equal to u CVB1 Therefore, during the entire cycle, when the voltage-equalizing capacitor is large enough, the output voltage is equal to the voltage of the voltage-equalizing capacitor, thus achieving self-equalization of the output voltage.

[0028] The present invention provides a bipolar self-equalizing center-tapped rectifier circuit, and the technical effects are as follows:

[0029] 1) The present invention can significantly reduce the problem of output voltage deviation of a bipolar center-tapped rectifier circuit when the load is unbalanced, and achieves a self-equalizing effect of the bipolar output voltage.

[0030] 2) The circuit has a simple topology, does not require a control system, is easy to implement, and is suitable for situations where bipolar voltage power supply is required.

[0031] 3) The circuit is simple to control and can achieve automatic voltage balancing of bipolar outputs by adding voltage balancing capacitors without the need for complex sampling and control algorithms. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0033] Figure 1 This is the schematic diagram of the bipolar center-tapped rectifier circuit before the voltage-equalizing capacitor is added.

[0034] Figure 2 This is a simulation diagram of the output voltage waveform of the bipolar center-tapped rectifier circuit under unbalanced load before adding the voltage-equalizing capacitor.

[0035] Figure 3 It is a circuit schematic diagram of the present invention.

[0036] Figure 4 The figure is a simulation diagram of the output voltage waveform when two loads are unbalanced when the present invention is used.

[0037] in: Figure 2 , Figure 4 All conditions are the same. DETAILED DESCRIPTION

[0038] Depend on Figure 1 It can be seen that the bipolar center-tapped rectifier circuit contains two secondary windings. Due to the problem of cross-regulation rate, the bipolar output voltage will produce voltage deviation when the load is unbalanced, and it is difficult to keep the dual output voltages consistent.

[0039] Depend on Figure 2 It can be seen that the output voltage difference of the bipolar center-tapped rectifier circuit when the load is unbalanced is 62V, which is difficult to meet the output voltage requirement under unbalanced load.

[0040] like Figure 3 As shown, a bipolar self-equalizing center-tapped rectifier circuit includes: a three-winding center-tapped rectifier circuit, two equalizing capacitors;

[0041] The three-winding center-tapped rectifier circuit includes an input source u s , three-winding transformer T, rectifier diode D P1 , rectifier diode D P2 , rectifier diode DN1 , rectifier diode D N2 , output capacitor C P , output capacitor C N , its connection form is as follows:

[0042] Input power s One end of the three-winding transformer T is connected to the primary winding L p One end, input power u s The other end is connected to the primary winding L of the three-winding transformer T p The other end;

[0043] The secondary winding L of the three-winding transformer T S1 By L S1-1 and L S1-2 Composition, L S1-1 One end and the rectifier diode D P1 Anode connection, L S1-2 The other end is connected to the rectifier diode D P2 Anode connection, L S1-1 The other end of L S1-2 The other end is connected to form a center tap, which is connected to the output capacitor C P The other end is connected;

[0044] The secondary winding L of the winding transformer T S2 By L S2-1 and L S2-2 Composition, L S2-1 One end and the rectifier diode D N1 Anode connection, L S2-2 The other end is connected to the rectifier diode D N2 Anode connection, L S2-1 The other end of L S2-2 The other end is connected to form a center tap, which is connected to the output capacitor C N The other end is connected;

[0045] Rectifier diode D P1 The cathodes of the diodes D P2 The cathode of the output capacitor C P one end of

[0046] Rectifier diode D N1 The cathodes of the rectifier diodes D N2 The cathode of the output capacitor C N one end of

[0047] Output capacitor C P The other end of the output capacitor C N one end of

[0048] The voltage grading capacitor includes a voltage grading capacitor C VB1 And the voltage balancing capacitor C VB2 The connection form is as follows:

[0049] Voltage balancing capacitor C VB1 One end of the three-winding transformer T is connected to the secondary winding L S1 One end, voltage balancing capacitor C VB1 The other end is connected to the secondary winding L of the three-winding transformer T S2 one end;

[0050] Voltage balancing capacitor C VB2 One end of the three-winding transformer T is connected to the secondary winding L S1 The other end, the voltage balancing capacitor C VB2 The other end is connected to the secondary winding L of the three-winding transformer T S2 The other end;

[0051] Load R P The two ends of the output capacitor C P One end of the load R N The two ends of the output capacitor C N one end and the other end.

[0052] The current is carried by the primary winding L of the three-winding transformer T p When one end flows into the rectifier diode D P1 and rectifier diode D N1 Conductivity;

[0053] The current is carried by the primary winding L of the three-winding transformer T p When the other end flows into the rectifier diode D P2 and rectifier diode D N2 Conductivity.

[0054] During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1 and L s2 The average voltage is 0, and the VB1 →L s1 →C VB2 →L s2 →C VB1 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB1 The voltage u CVB1 Equal to the voltage balancing capacitor C VB2 The voltage u CVB2 .

[0055] During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1-1 and L s2-1 The average voltage is 0, and the VB1→L s1-1 →C N →L s2-1 →C VB1 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB1 The voltage u CVB1 Equal to the output capacitance C N The voltage u CN .

[0056] During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1-2 and L s2-2 The average voltage is 0, and C VB2 →L s1-2 →C N →L s2-2 →C VB2 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB2 The voltage u CVB2 Equal to the output capacitance C N The voltage u CN .

[0057] When the current flows through the primary winding L of the three-winding transformer T p When one end flows into the rectifier diode D P1 and rectifier diode D N1 Conducting, voltage balancing capacitor C VB1 Through the rectifier diode D P1 and rectifier diode D N1 With output capacitor C P In parallel, there is an output capacitor C P The voltage u CP Equal to u CVB1 ; Voltage balancing capacitor C VB2 Through the transformer secondary coil L s1 , L s2 and rectifier diode D P1 , rectifier diode D N1 With output capacitor C P In parallel, due to the transformer secondary coil L s1 and L s2 The number of turns is equal, so there is an output capacitor C P The voltage u CP Equal to u CVB2 ;

[0058] When the current flows through the primary winding L of the three-winding transformer T p When the other end flows into the rectifier diode D P2 and rectifier diode D N2 Conducting, voltage balancing capacitor C VB2 Through the rectifier diode D P2 and rectifier diode DN2 With output capacitor C P In parallel, there is an output capacitor C P The voltage u CP Equal to u CVB2 ; Voltage balancing capacitor C VB1 Through the transformer secondary coil L s1 , L s2 and rectifier diode D P2 , rectifier diode D N2 With output capacitor C P In parallel, due to the transformer secondary coil L s1 and L s2 The number of turns is equal, so there is an output capacitor C P The voltage u CP Equal to u CVB1 Therefore, during the entire cycle, when the voltage-equalizing capacitor is large enough, the output voltage is equal to the voltage of the voltage-equalizing capacitor, thus achieving self-equalization of the output voltage.

[0059] Depend on Figure 4 It can be seen that when the present invention is used, the output voltages under unbalanced loads on the two paths are equal and have no difference, which effectively reduces the output voltage difference of the bipolar center-tapped rectifier circuit. In the case of unbalanced loads, the output voltage is self-equalized by relying solely on the circuit itself, and the voltage deviation is only 0.2V, which solves the problem that the output cannot be self-equalized.

Claims

1. A bipolar self-equalizing center-tapped rectifier circuit, characterized in that: The circuit comprises: a three-winding center-tapped rectifier circuit and two voltage-equalizing capacitors; The three-winding center-tapped rectifier circuit includes an input source u s , three-winding transformer T, rectifier diode D P1 , rectifier diode D P2 , rectifier diode D N1 , rectifier diode D N2 , output capacitor C P , output capacitor C N , its connection form is as follows: Input power s One end of the three-winding transformer T is connected to the primary winding L p One end, input power u s The other end is connected to the primary winding L of the three-winding transformer T p The other end; The secondary winding L of the three-winding transformer T S1 Including winding unit L S1-1 and winding unit winding L S1-2 , winding unit L S1-1 One end and the rectifier diode D P1 Anode connection, winding unit L S1-2 The other end is connected to the rectifier diode D P2 Anode connection; Winding unit L S1-1 The other end of the winding unit L S1-2 One end of the output capacitor C is connected to form a first center tap. P The other end is connected; The secondary winding L of the three-winding transformer T S2 Including winding unit L S2-1 and winding unit L S2-2 , winding unit L S2-1 One end and the rectifier diode D N1 Anode connection, winding unit L S2-2 The other end is connected to the rectifier diode D N2 Anode connection; Winding unit L S2-1 The other end of the winding unit L S2-2 The second center tap is connected to the output capacitor C N The other end is connected; Rectifier diode D P1 The cathodes of the diodes D P2 The cathode of the output capacitor C P One end Rectifier diode D N1 The cathodes of the diodes D N2 The cathode of the output capacitor C N one end of Output capacitor C P The other end of the output capacitor C N one end of The voltage grading capacitor includes a voltage grading capacitor C VB1 And the voltage balancing capacitor C VB2 , its connection form is as follows: Voltage balancing capacitor C VB1 One end of the three-winding transformer T is connected to the secondary winding L S1 One end, voltage balancing capacitor C VB1 The other end is connected to the secondary winding L of the three-winding transformer T S2 one end; Voltage balancing capacitor C VB2 One end of the three-winding transformer T is connected to the secondary winding L S1 The other end, the voltage balancing capacitor C VB2 The other end is connected to the secondary winding L of the three-winding transformer T S2 The other end; Load R P The two ends of the output capacitor C P One end of the output capacitor C P The other end of the load R N The two ends of the output capacitor C N One end of the output capacitor C N The other end of During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1 and L s2 The average voltage is 0, and C VB1 →L s1 →C VB2 →L s2 →C VB1 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB1 The voltage u CVB1 Equal to the voltage balancing capacitor C VB2 The voltage u CVB2 ; During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1-1 and L s2-1 The average voltage is 0, and C VB1 →L s1-1 →C N →L s2-1 →C VB1 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB1 The voltage u CVB1 Equal to the output capacitance C N The voltage u CN ; During the entire switching cycle, the transformer secondary coil L is known from the volt-second balance principle. s1-2 and L s2-2 The average voltage is 0, and C VB2 →L s1-2 →C N →L s2-2 →C VB2 The KVL principle of the loop can obtain the voltage-equalizing capacitor C VB2 The voltage u CVB2 Equal to the output capacitance C N The voltage u CN ; When the current flows through the primary winding L of the three-winding transformer T p When one end flows into the rectifier diode D P1 and rectifier diode D N1 Conducting, voltage balancing capacitor C VB1 Through the rectifier diode D P1 and rectifier diode D N1 With output capacitor C P In parallel, there is an output capacitor C P The voltage u CP Equal to u CVB1 ; Voltage balancing capacitor C VB2 Through the transformer secondary coil L s1 , L s2 and rectifier diode D P1 , rectifier diode D N1 With output capacitor C P In parallel, due to the transformer secondary coil L s1 and L s2 The number of turns is equal, so there is an output capacitor C P The voltage u CP Equal to u CVB2 ; When the current flows through the primary winding L of the three-winding transformer T p When the other end flows into the rectifier diode D P2 and rectifier diode D N2 Conducting, voltage balancing capacitor C VB2 Through the rectifier diode D P2 and rectifier diode D N2 With output capacitor C P In parallel, there is an output capacitor C P The voltage u CP Equal to u CVB2 ; Voltage balancing capacitor C VB1 Through the transformer secondary coil L s1 , L s2 and rectifier diode D P2 , rectifier diode D N2 With output capacitor C P In parallel, due to the transformer secondary coil L s1 and L s2 The number of turns is equal, so there is an output capacitor C P The voltage u CP Equal to u CVB1 Therefore, during the entire cycle, when the voltage-equalizing capacitor is large enough, the output voltage is equal to the voltage of the voltage-equalizing capacitor, thus achieving self-equalization of the output voltage.

2. A bipolar self-equalizing center-tapped rectifier circuit according to claim 1, characterized in that: The current is drawn by the primary winding L of the three-winding transformer T p When one end flows into the rectifier diode D P1 and rectifier diode D N1 Conductivity; The current is drawn by the primary winding L of the three-winding transformer T p When the other end flows into the rectifier diode D P2 and rectifier diode D N2 Conductivity.

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