CN101247090A - Multiphase DC-DC Converter - Google Patents

Abstract

The invention relates to a multi-phase DC-DC converter, comprising at least two resonant converter circuits connected in parallel between the input positive and negative busbars and the output positive and negative busbars, and sending control signals to ensure that the resonant converter circuits have the same frequency and wrong phase The working control circuit has a pre-regulator circuit between any resonant converter circuit and the input positive and negative busbars. The control circuit controls the pre-regulator circuit to work at the same frequency and out of phase, and at the same time adjusts the output voltage of the pre-regulator circuit to make the output current of the resonant converter circuit the same. The implementation of the multi-phase DC-DC converter can make the two resonant converters work at the same frequency and out of phase, respectively adjust the voltage of the two pre-regulator circuits to make the output voltage of the two resonant converters the same, so that the two resonant converters The output current is the same. Therefore, when the resonance parameters of the two resonant converters are different, the currents of the two circuits are unbalanced, and even one circuit does not transmit power to the secondary side.

Description

Multiphase DC-DC Converter

technical field

The present invention relates to a multi-phase DC-DC converter, more particularly, to a multi-phase DC-DC converter in which at least two pre-regulator circuits are respectively connected in series with at least two parallel-connected resonant converters.

Background technique

Patent US6583999B1 discloses a DC-DC converter as shown in FIG. 1 . The DC-DC converter includes a BOOST circuit and a pair of parallel-connected resonant converter circuits. The first and second resonant converter circuits operate at the same frequency with a 90-degree phase shift to reduce output ripple current. However, if there is a difference in the resonance parameters of the first and second resonant converters, the currents of the two circuits will be unbalanced, and when the difference in resonance parameters is relatively large, one circuit may even not transmit power to the secondary side.

Contents of the invention

The technical problem to be solved by the present invention is to provide a multi-phase DC-DC converter in which at least two pre-regulator circuits are respectively connected in series with at least two parallel resonant converters, aiming at the above defects of the prior art.

The technical solution adopted by the present invention to solve the technical problem is: to construct a multi-phase DC-DC converter, including at least two resonant converter circuits connected in parallel between the input positive and negative busbars and the output positive and negative busbars and by sending The control signal ensures that the resonant converter circuit works at the same frequency and out of phase. There is a pre-regulator circuit between any of the resonant converter circuits and the input positive and negative bus bars. The control circuit controls the pre-regulator circuit to work at the same frequency and out of phase, and at the same time adjusts the output voltage of the pre-regulator circuit to make the output current of the resonant converter circuit the same.

In the multi-phase DC-DC converter of the present invention, the pre-regulator circuit is a BOOST type pre-regulator circuit or a power factor correction circuit.

In the multi-phase DC-DC converter of the present invention, the resonant converter circuit is a series resonant converter circuit, a parallel resonant converter circuit or a series-parallel resonant converter circuit.

In a preferred embodiment, the multi-phase DC-DC converter of the present invention includes a first resonant converter circuit and a second resonant converter circuit, and a first pre-regulator circuit and a second pre-regulator circuit respectively located in front of them. regulator circuit.

Further, the first pre-regulator circuit includes an inductance element L11, a diode D11, a switch tube S11 and a capacitor C11;

One end of the inductance element L11 is connected to the input positive bus, and the other end is respectively connected to the anode of the diode D11 and the first end of the switching tube S11;

The second end of the switching tube S11 is connected to the input negative bus, and the control end is connected to the control circuit;

One end of the capacitor C11 is connected to the cathode of the diode D11, and the other end is connected to the input negative bus.

The second pre-regulator circuit includes an inductance element L12, a diode D12, a switch tube S12 and a capacitor C12;

One end of the inductance element L12 is connected to the input positive bus, and the other end is respectively connected to the anode of the diode D12 and the first end of the switching tube S12;

The second end of the switching tube S12 is connected to the input negative bus, and the control end is connected to the control circuit;

One end of the capacitor C12 is connected to the cathode of the diode D12, and the other end is connected to the input negative bus.

Preferably, the switch tube S11 and the switch tube S12 are conducted alternately at the same frequency and phase-shifted by 180 degrees.

In another preferred embodiment, the multi-phase DC-DC converter of the present invention includes a first resonant converter circuit and a second resonant converter circuit, and the first pre-regulator circuit and the second resonant converter circuit are respectively connected in front of it. In the pre-regulator circuit, the first resonant converter circuit and the second resonant converter circuit are half-bridge, full-bridge or three-electric structures.

Preferably, the first resonant converter circuit includes a first resonant circuit, a transformer T1 and a first rectifier circuit; the output end of the first resonant circuit is connected to the transformer T1, and the output end of the transformer T1 is connected to the first rectifier circuit circuit, the first rectification circuit is bridge rectification or synchronous rectification;

The second resonant converter circuit includes a second resonant circuit, a transformer T2 and a second rectifier circuit; the output end of the second resonant circuit is connected to the transformer T2, and the output end of the transformer T2 is connected to the second rectifier circuit, so The second rectification circuit is bridge rectification or synchronous rectification

The first resonant circuit includes: a switch tube S1, a switch tube S2, a capacitor Cr1, a capacitor Cr2, and an inductance element Lr1;

Wherein, the first terminal of the switching tube S1 is connected to the output terminal of the first pre-regulator circuit, and the second terminal of the switching tube S1 is respectively connected to the first terminal of the switching tube S2 and the transformer T1 One end of the primary winding is connected;

The second end of the switching tube S2 is connected to the input negative bus;

One end of the capacitor Cr1 is connected to the output end of the first pre-regulator circuit, and the other end is respectively connected to one end of the capacitor Cr2 and one end of the inductance element Lr1;

The other end of the capacitor Cr2 is connected to the input negative bus;

The other end of the inductance element Lr1 is connected to the other end of the primary winding of the transformer T1;

The second resonant circuit includes: a switch tube S3, a switch tube S4, a capacitor Cr3, a capacitor Cr4, and an inductance element Lr2;

Wherein, the first end of the switching tube S3 is connected to the output end of the second pre-regulator circuit, and the second end of the switching tube S3 is respectively connected to the first end of the switching tube S4 and the transformer T2 One end of the primary winding is connected;

The second end of the switching tube S4 is connected to the input negative bus;

One end of the capacitor Cr3 is connected to the output end of the second pre-regulator circuit, and the other end is respectively connected to one end of the capacitor Cr4 and one end of the inductance element Lr2;

The other end of the capacitor Cr4 is connected to the input negative bus;

The other end of the inductance element Lr2 is connected to the other end of the primary winding of the transformer T2;

The control terminals of the switching tubes S1, S2, S3 and S4 are connected to the control circuit.

Preferably, the switching transistors S1 and S3 are conducted alternately at the same frequency and phase-shifted by 90 degrees.

Preferably, the switching tube S2 and the switching tube S4 are conducted alternately at the same frequency and phase-shifted by 90 degrees.

Preferably, the multi-phase DC-DC converter of the present invention further includes a filter capacitor Co connected between the parallel-connected resonant converter circuit and the output positive and negative bus bars.

The beneficial effect of the present invention is that the two resonant converters can work at the same frequency and out of phase, respectively adjust the circuit voltages of the two pre-regulators to make the output voltages of the two resonant converters the same, so that the output currents of the two resonant converters are the same . Therefore, when the resonance parameters of the two resonant converters are different, the currents of the two circuits are unbalanced, and even one circuit does not transmit power to the secondary side.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is a schematic circuit diagram of a multi-phase DC-DC converter in the prior art;

Fig. 2 is the schematic block diagram of the circuit of the first embodiment of the multi-phase DC-DC converter of the present invention;

Fig. 3 is the circuit principle block diagram of the second embodiment of the multi-phase DC-DC converter of the present invention

Detailed ways

The multiphase DC-DC converter of the present invention includes at least two resonant converter circuits connected in parallel between the input positive and negative bus bars 11, 12 and the output positive and negative bus bars 21, 22, and the synchronous resonant converter circuits are guaranteed by sending control signals. The control circuit 7 that works in frequency-staggered phase has a pre-regulator circuit between any resonant converter circuit and the input positive and negative bus bars. The control circuit 7 controls the pre-regulator circuit to work at the same frequency and out of phase, and at the same time adjusts the output voltage of the pre-regulator circuit to make the output current of the resonant converter circuit the same. In implementation, the pre-regulator circuit can be a BOOST type pre-regulator circuit or a power factor correction circuit; the resonant converter circuit is a series resonant converter circuit, a parallel resonant converter circuit or a series-parallel resonant converter circuit.

When the multiphase DC-DC converter includes two BOOST type pre-regulator circuits and two half-bridge resonant converter circuits, the input ends of the two BOOST type pre-regulator circuits are coupled to the input bus, and the two BOOST type pre-regulator circuits are coupled to the input bus. The output of the regulator circuit is respectively used as the input of two half-bridge resonant converters, the output terminals of the two half-bridge resonant converter circuits are coupled to the output positive and negative busbars, and a filter capacitor is coupled to the output positive and negative busbars. The control circuit ensures that the two half-bridge resonant converters work at the same frequency with a phase difference of 90 degrees, and the two BOOST pre-regulator circuits work at the same frequency with a phase difference of 180 degrees. The output voltages of the two BOOST type pre-regulator circuits, the output voltage of the resonant converter and the output current signals of the two resonant converters are used as the input signals of the control circuit. The output of the two BOOST type pre-regulator circuits has no coupling and has a separate voltage loop. The output current of the two half-bridge resonant converters is used as the voltage loop input signal of the two BOOST type pre-regulator circuits to adjust the two BOOST type pre-regulator circuits respectively. The output voltage of the pre-regulator circuit makes the output voltage of the two half-bridge resonant converters the same, so that the output currents of the two half-bridge resonant converters are the same. The resonant converter circuit may be a series resonant converter circuit, a parallel resonant converter circuit, a series-parallel resonant converter circuit or an LLC resonant converter circuit.

As shown in FIG. 2, in a preferred implementation, the multiphase DC-DC converter includes a first resonant converter circuit 3 and a second resonant converter circuit 4, and a first pre-regulator circuit 5 and a second resonant converter circuit respectively located in front of them. Two pre-regulator circuits 6 . The first pre-regulator circuit 5 includes an inductance element L11, a diode D11, a switch tube S11 and a capacitor C11; one end of the inductance element L11 is connected to the input positive bus bar 11, and the other end is respectively connected to the anode of the diode D11 and the first switch tube S11. One end is connected; the second end of the switch tube S11 is connected to the input negative bus 12 , and the control end is connected to the control circuit 7 ; one end of the capacitor C11 is connected to the cathode of the diode D11 , and the other end is connected to the input negative bus 12 . The second pre-regulator circuit includes an inductance element L12, a diode D12, a switch tube S12 and a capacitor C12; one end of the inductance element L12 is connected to the input positive bus 11, and the other end is respectively connected to the anode of the diode D12 and the first end of the switch tube S12 The second end of the switch tube S12 is connected to the input negative bus 12, and the control end is connected to the control circuit 7; one end of the capacitor C12 is connected to the cathode of the diode D12, and the other end is connected to the input negative bus 12 . In a specific operation, the switch tube S11 and the switch tube S12 can be alternately conducted at the same frequency and phase-shifted by 180 degrees.

In a further preferred implementation, the first resonant converter circuit 3 includes a first resonant circuit 31, a transformer T1 and a rectifier circuit 33; the output end of the first resonant circuit 31 is connected to the transformer T1, and the output end of the transformer T1 is connected to the first rectifier circuit Electric (3), the first rectified electric (3) is bridge rectification or synchronous rectification; The second resonant converter circuit 4 comprises the second resonant circuit 32 and transformer T2; The output end of the second resonant circuit 41 is connected with transformer T2, The output terminal of the transformer T2 is connected to the second rectification circuit 43, and the rectification circuit 43 is bridge rectification or synchronous rectification

The first resonant circuit 31 includes: a switch tube S1, a switch tube S2, a capacitor Cr1, a capacitor Cr2, and an inductance element Lr1; wherein, the first end of the switch tube S1 is connected to the output end of the first pre-regulator circuit 5, and the switch The second end of the tube S1 is respectively connected to the first end of the switch tube S2 and one end of the primary winding of the transformer T1; the second end of the switch tube S2 is connected to the input negative bus 12; one end of the capacitor Cr1 is connected to the first pre- The output end of the regulator circuit 5 is connected, and the other end is respectively connected to one end of the capacitor Cr2 and one end of the inductance element Lr1; the other end of the capacitor Cr2 is connected to the input negative bus 12; the other end of the inductance element Lr1 is connected to the primary winding of the transformer T1 The other end; the second resonant circuit 41 includes: a switch tube S3, a switch tube S4, a capacitor Cr3, a capacitor Cr4 and an inductance element Lr2; wherein, the first end of the switch tube S3 is connected to the output end of the second pre-regulator circuit 6 connection, the second end of the switch tube S3 is respectively connected to the first end of the switch tube S4 and one end of the primary winding of the transformer T2; the second end of the switch tube S4 is connected to the input negative bus 12; one end of the capacitor Cr3 is connected to the first end of the transformer T2 The output end of the two pre-regulator circuit 6 is connected, and the other end is connected with one end of the capacitor Cr4 and one end of the inductance element Lr2 respectively; the other end of the capacitor Cr4 is connected to the input negative bus 12; the other end of the inductance element Lr2 is connected to the original of the transformer T2 The other end of the side winding; the control terminals of the switch tube S1 , switch tube S2 , switch tube S3 and switch tube S4 are connected to the control circuit 7 . In specific work, the switch tubes S1 and S3 are conducted alternately at the same frequency and phase-shifted by 90 degrees. The switch tube S2 and the switch tube S4 are conducted alternately at the same frequency and phase-shifted by 90 degrees.

As shown in FIG. 3 , in another preferred implementation, the first resonant converter circuit 3 includes: a first resonant circuit 31 , a transformer T1 and a first rectifier circuit 33 connected in series in sequence. The first resonant circuit 31 includes: switch tubes S1, S2, S3, S4, capacitor Cr1 and inductance element Lr1; wherein, the first ends of the switch tubes S1, S3 are connected to the output end of the pre-regulator circuit 5, and the switch tube S1 The second end is respectively connected with the first end of the switch tube S2 and one end of the capacitor Cr1; the other end of the capacitor Cr1 is connected with one end of the primary winding of the transformer T1; the second end of the switch tube S3 is respectively connected with the first end of the switch tube S4 The terminal is connected to one end of the inductance element Lr1; the other end of the inductance element Lr1 is connected to the other end of the primary winding of the transformer T1, and the second end of the switch tubes S3 and S4 is connected to the input negative bus 12; the switch tubes S1, S2, S3 , The control end of S4 is connected to the control circuit 7. The switch tubes S1 and S3 are turned on alternately at the same frequency and phase-shifted by 90 degrees. The switch tube S1 and the switch tube S3 are conducted alternately at the same frequency and phase-shifted by 90 degrees. The switch tube S2 and the switch tube S4 are conducted alternately at the same frequency and phase-shifted by 90 degrees. The rectification circuit 33 is bridge rectification or synchronous rectification. The second resonant converter circuit 4 is a half-bridge, full-bridge or three-electric structure, including: a first resonant circuit 41 , a transformer T2 and a second rectifier circuit 43 connected in series in sequence. The first resonant circuit 41 includes: switch tubes S5, S6, S7, S8, capacitor Cr2 and inductance element Lr2; wherein, the first ends of the switch tubes S5, S7 are connected to the output end of the pre-regulator circuit 6, and the switch tube S5 The second end is respectively connected with the first end of the switch tube S6 and one end of the capacitor Cr2; the other end of the capacitor Cr2 is connected with one end of the primary winding of the transformer T2; the second end of the switch tube S7 is respectively connected with the first end of the switch tube S8 end is connected to one end of the inductance element Lr2; the other end of the inductance element Lr2 is connected to the other end of the primary winding of the transformer T2, and the second end of the switch tubes S6 and S8 is connected to the input negative bus 12; the switch tubes S5, S6, S7 , The control terminal of S8 is connected to the control circuit 7. The rectification circuit 43 is bridge rectification or synchronous rectification.

In a further implementation, the multi-phase DC-DC converter further includes a filter capacitor Co connected between the parallel-connected resonant converter circuits 3 , 4 and the output positive and negative bus bars 21 , 22 . The current frequency of the filter capacitor Co is four times the switching frequency of the switching tubes S1, S2, S3 or S4.

The present invention is described through some embodiments, and those skilled in the art know that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, the features and examples may be modified to adapt a particular situation and material to the teachings of the invention without departing from the spirit and scope of the invention. Therefore, the present invention is not limited by the specific embodiments disclosed here, and all embodiments falling within the scope of the claims of the present application belong to the protection scope of the present invention.

Claims (11)

1, a kind of multiphase DC-DC converter, comprise at least two controlled resonant converter circuit being connected in parallel between input positive and negative busbar (11,12) and output positive and negative busbar (21,22) and guarantee the control circuit (7) of described controlled resonant converter circuit by transmitting control signal with the work of frequency misphase, it is characterized in that between arbitrary described controlled resonant converter circuit and described input positive and negative busbar, the pre-regulator circuit being arranged all.The described pre-regulator circuit of described control circuit (7) control by regulating the output voltage of described pre-regulator circuit, makes described controlled resonant converter circuit output current identical with misphase work frequently simultaneously.

2, multiphase DC-DC converter according to claim 1 is characterized in that, described pre-regulator circuit is BOOST type pre-regulator circuit or power factor correction circuit.

3, multiphase DC-DC converter according to claim 1 is characterized in that, described controlled resonant converter circuit is series resonant converter circuit, parallel resonance converter circuit or series parallel resonance converter circuit.

4, according to any described multiphase DC-DC converter of claim 1～3, it is characterized in that, comprise the first controlled resonant converter circuit (3) and the second controlled resonant converter circuit (4), and lay respectively at the first pre-regulator circuit (5) and the second pre-regulator circuit (6) before it.

5, multiphase DC-DC converter according to claim 4 is characterized in that, the described first pre-regulator circuit (5) comprises inductance component L 11, diode D11, switching tube S11 and capacitor C 11;

One end of described inductance component L 11 is connected with described input positive bus-bar (11), and the other end is connected with the anode of described diode D11 and first end of described switching tube S11 respectively;

Second end of described switching tube S11 is connected with described input negative busbar (12), control end is connected to described control circuit (7);

One end of described capacitor C 11 is connected with the negative electrode of described diode D11, and the other end is connected with described input negative busbar (12).

The described second pre-regulator circuit (6) comprises inductance component L 12, diode D12, switching tube S12 and capacitor C 12;

One end of described inductance component L 12 is connected with described input positive bus-bar (11), and the other end is connected with the anode of described diode D12 and first end of described switching tube S12 respectively;

Second end of described switching tube S12 is connected with described input negative busbar (12), and control end is connected to described control circuit (7);

One end of described capacitor C 12 is connected with the negative electrode of described diode D12, and the other end is connected with described input negative busbar (12).

According to any described multiphase DC-DC converter of claim 5, it is characterized in that 6, described switching tube S11 and described switching tube S12 are with the frequency displacement staggered conducting of 180 degree mutually.

7, according to any described multiphase DC-DC converter of claim 1～3, it is characterized in that, comprise the first controlled resonant converter circuit (3) and the second controlled resonant converter circuit (4), be connected with the first pre-regulator circuit (5) and the second pre-regulator circuit (6) before it respectively, the described first controlled resonant converter circuit (3) and the second controlled resonant converter circuit (4) are half-bridge, full-bridge or three electric structures.

8, multiphase DC-DC converter according to claim 7 is characterized in that, the described first controlled resonant converter circuit (3) comprises first resonant circuit (31), transformer T1 and first rectification circuit (33); The output of described first resonant circuit (31) is connected with transformer T1, and the output of described transformer T1 connects first rectification circuit (33), and described first rectification circuit (33) is bridge rectifier or synchronous rectification;

The described second controlled resonant converter circuit (4) comprises second resonant circuit (32), transformer T2 and second rectification circuit (43); The output of described second resonant circuit (41) is connected with transformer T2, and the output of described transformer T2 connects second rectification circuit (43), and described second rectification circuit (43) is bridge rectifier or synchronous rectification

Described first resonant circuit (31) comprising: switching tube S1, switching tube S2, capacitor C r1, capacitor C r2 and inductance component L r1;

Wherein, first end of described switching tube S1 is connected with the output of the described first pre-regulator circuit (5), and second end of described switching tube S1 is connected with the former limit of described transformer T1 winding one end with first end of described switching tube S2 respectively;

Second end of described switching tube S2 is connected to described input negative busbar (12);

The end of described capacitor C r1 is connected with the output of the described first pre-regulator circuit (5), the other end is connected with the end of described capacitor C r2 and the end of described inductance component L r1 respectively;

The other end of described capacitor C r2 is connected to input negative busbar (12);

The other end of described inductance component L r1 is connected to the former limit of the described transformer T1 winding other end;

Described second resonant circuit (41) comprising: switching tube S3, switching tube S4, capacitor C r3, capacitor C r4 and inductance component L r2;

Wherein, first end of described switching tube S3 is connected with the output of the described second pre-regulator circuit (6), and second end of described switching tube S3 is connected with first end of described switching tube S4 and an end of the former limit of described transformer T2 winding respectively;

Second end of described switching tube S4 is connected to described input negative busbar (12);

The end of described capacitor C r3 is connected with the output of the described second pre-regulator circuit (6), the other end is connected with the end of described capacitor C r4 and the end of described inductance component L r2 respectively;

The other end of described capacitor C r4 is connected to input negative busbar (12);

The other end of described inductance component L r2 is connected to the other end of the former limit of described transformer T2 winding;

The control end of described switching tube S1, switching tube S2, switching tube S3, switching tube S4 is connected to described control circuit (7).

9, multiphase DC-DC converter according to claim 8, described switching tube S1 and S3 are with the frequency displacement staggered conducting of 90 degree mutually.

10, multiphase DC-DC converter according to claim 8 is characterized in that, described switching tube S2 and described switching tube S4 are with the frequency displacement staggered conducting of 90 degree mutually.

11, any according to Claim 8 described multiphase DC-DC converter is characterized in that, also comprises the filter capacitor Co that is connected between described controlled resonant converter circuit (3,4) in parallel and the output positive and negative busbar (21,22).

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