WO2020253460A1

WO2020253460A1 - Parallel resonance convertor and power supply

Info

Publication number: WO2020253460A1
Application number: PCT/CN2020/091432
Authority: WO
Inventors: 胡永辉
Original assignee: 中兴通讯股份有限公司
Priority date: 2019-06-17
Filing date: 2020-05-20
Publication date: 2020-12-24
Also published as: CN112104232A

Abstract

Disclosed in the present invention are a parallel resonance convertor (10) and a power supply (100). The parallel resonance convertor (10) comprises at least two resonant converters (20, 22) connected in parallel, wherein the at least two resonant converters (20, 22) connected in parallel share a resonant capacitor (24) and a resonant inductor (26).

Description

Parallel resonance converter and power supply

cross reference

This application is cited in the Chinese Patent Application No. 201910521978.5 entitled "Parallel Resonant Converter and Power Supply" filed on June 17, 2019, which is fully incorporated into this application by reference.

Technical field

The invention relates to the field of power electronics, in particular to a parallel resonant converter and power supply.

Background technique

In the field of power electronics technology, especially DC/DC converters, the parallel resonant converter shown in Figure 1 is used for high-power output occasions, which can make the distribution of power hot spots more uniform, which is beneficial to the heat dissipation design of the power supply. However, in the actual mass-produced products, there are tolerances in the parameters of the resonant inductors L _r1 and L _r2 and the resonant capacitors C _r1 and C _r2 as shown in Figure 1, which will cause the voltage gains of the two resonant converters to be inconsistent. This directly causes the output currents I _o1 and I _{o2 of the} two resonant converters to be inconsistent, and there may even be only one resonant converter with output current, which may cause the power device to burn out in severe cases.

At present, the commonly used solutions to solve the current sharing problem mainly include: 1. Improve the current sharing by adjusting the capacitance of the resonant capacitor or the inductance of the resonance inductance by adding power devices; 2. Adding a pre-adjustment circuit to improve current sharing and increase current sharing Control strategies, etc. However, the above-mentioned processing schemes will bring about increased costs or complex control strategies.

Therefore, for high-power output occasions, it is necessary to propose a parallel resonant converter that neither requires additional components nor complex control strategies.

Summary of the invention

An embodiment of the present invention provides a parallel resonant converter, including at least two parallel resonant converters, wherein at least two parallel resonant converters share a resonant capacitor and a resonant inductor.

The embodiment of the present invention also provides a power supply including the above-mentioned parallel resonant converter.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented in accordance with the content of the description, and in order to make the above and other objectives, features and advantages of the present invention more obvious and understandable. In the following, specific embodiments of the present invention are specifically cited.

Description of the drawings

By reading the detailed description of the following embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only used for the purpose of illustrating the embodiments, and are not considered as a limitation to the present invention. Also, throughout the drawings, the same reference symbols are used to denote the same components. In the attached picture:

Figure 1 is a schematic diagram of an equivalent circuit of a parallel resonant converter in the prior art;

Figure 2 is a schematic diagram of a parallel resonant converter according to an embodiment of the present invention;

3 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 1 of the embodiment of the present invention;

4 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 2 of the embodiment of the present invention;

5 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 3 of the embodiment of the present invention;

6 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 4 of the embodiment of the present invention;

7 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 5 of the embodiment of the present invention;

8 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 6 of the embodiment of the present invention;

9 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 7 of the embodiment of the present invention;

10 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 8 of the embodiment of the present invention;

11 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 9 of the embodiment of the present invention;

Fig. 12 is a schematic structural diagram of a power supply according to an embodiment of the present invention.

Detailed ways

Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

According to an embodiment of the present invention, a parallel resonant converter is provided. FIG. 2 is a schematic diagram of a parallel resonant converter 10 according to an embodiment of the present invention. As shown in FIG. 2, it includes a first resonant converter 20 and a second resonant converter. 22. The first resonant converter 20 and the second resonant converter 22 share a resonant capacitor 24 and a resonant inductor 26.

In the embodiment of the present invention, the topological structure of the resonant converter may be: an asymmetric half-bridge resonant converter topology, a symmetrical half-bridge resonant converter topology, a full-bridge resonant converter topology, and a three-level half-bridge resonant converter Converter topology, or three-level full-bridge resonant converter topology. The resonant converter can be: LLC resonant converter or series resonant converter.

In addition, in the embodiment of the present invention, the resonant capacitor 24 may be a capacitor or a resonant capacitor group. Similarly, the resonant inductor 26 can be an inductor or a resonant inductor group. In addition, in another example, the resonant inductor 26 may also be the leakage inductance of the second transformer T ₂ .

In addition, in the embodiment of the present invention, in order to reduce the volume and loss of the magnetic element, in one example, the resonant inductor 26 and the transformers of at least two resonant converters are magnetically integrated into a pair of magnetic cores to form the first transformer T ₁ . In another example, the transformers of at least two resonant converters are magnetically integrated into a pair of magnetic cores to form the second transformer T ₂ . When the resonant converter is a symmetrical half-bridge resonant converter topology, the resonant capacitor 24 can also be connected in parallel with a diode.

Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

It can ensure natural current sharing between the two resonant converters; through the integration of magnetic components, the number and volume of magnetic components are reduced, and the power density of the power supply is increased; in addition, the core loss of the magnetic components is reduced, and the The efficiency of the power supply is improved; at the same time, the cost of magnetic components is reduced.

The above-mentioned technical solutions of the embodiments of the present invention will be exemplified below in conjunction with the drawings and examples.

Example 1:

1. The topological structure of the resonant converter is: two-way asymmetric half-bridge resonant converter topology;

2. The resonant inductance shared by the two resonant converters, the excitation inductance of the two transformers, and the primary and secondary windings of the two transformers are magnetically integrated into a pair of magnetic cores to form the first transformer T;

Fig. 3 is a schematic diagram of an equivalent circuit of the parallel resonant converter of Example 1 of the embodiment of the present invention. As shown in Figure 3, in Example 1, it is a parallel connection of two asymmetric half-bridge resonant converters, including the first switching devices S1 and S2, the first rectifying devices S10 and S20, and the second The switching devices S3 and S4, the second rectifier devices S30 and S40, the resonant capacitor Cr shared by the two resonant converters, the resonant inductor Lr shared by the two resonant converters, and the excitation inductances Lm1, Lm2 and two The primary and secondary windings of the transformer are magnetically integrated into a pair of magnetic cores to form T. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. Io1 and Io2 represent the corresponding output currents of the two resonant converters.

In order to verify the current sharing effect of the parallel resonant converter of the embodiment of the present invention, the embodiment of the present invention provides a simulation experiment of the parallel resonant converter in the prior art as shown in FIG. 1 and the circuit shown in FIG. 3, and the simulation results See data sheet 1.

Table 1 Simulation data table

As shown in Table 1, the circuit shown in Figure 1 simulates 4 operating conditions: When the tolerance of the resonant inductor and the resonant capacitor of the two half-bridge converters is +/-5%, the two half-bridge converters One of them has an output current of 48A and the other has only 12A. The current between the two circuits is seriously unbalanced; when the resonance parameters of the two half-bridge converters are only the resonance inductance or only the tolerance of the resonance capacitance is +/-5%, the two half-bridge converters One of the bridge converters has an output current of 40A and the other has only 20A. The current between the two is still unbalanced; when the resonance parameters of the two half-bridge converters are the same, one of the two half-bridge converters has an output current of 30A, and the other is also 30A, current balance between the two channels. This also shows that only when the parameters of the two half-bridge resonant converters are the same, the current between the two circuits can be balanced. Because the circuit shown in Figure 3 shares the resonance capacitance and resonance inductance, the resonance parameters are consistent. The simulation results in Table 1 also show that with the circuit shown in Figure 3, the currents are balanced between the two paths.

It can be seen from the above experimental results that in Example 1, because a set of resonant capacitors and resonant inductors are shared, the two transformers are magnetically integrated into a pair of magnetic cores, and the resonance parameters of the two resonant converters are the same. The voltage gain of the two resonant converters is the same, so there is no current sharing problem between the two resonant converters. Since the four magnetic elements of the two-way resonant converter of the prior art are magnetically integrated on one pair of magnetic cores or two pairs of magnetic cores, the present invention reduces the volume and loss of the magnetic elements and at the same time reduces the cost of the magnetic elements.

Example 2

2. The excitation inductances of the two-circuit transformers and the primary and secondary windings of the two-circuit transformers are magnetically integrated into a pair of magnetic cores to form the first transformer T;

4 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 2 of the embodiment of the present invention. The parallel resonant converter shown in FIG. 4 is a parallel connection of two asymmetric half-bridge resonant converters, including the first The switching devices S1 and S2 of the first road, the rectifying devices S10 and S20 of the first road, the switching devices S3 and S4 of the second road, the rectifying devices S30 and S40 of the second road, the resonant capacitor Cr shared by the two resonant converters and two The resonant inductance Lr shared by the resonant converters, the excitation inductances Lm1 and Lm2 of the two-circuit transformers, and the primary and secondary windings of the two-circuit transformers are magnetically integrated to form a magnetic core. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. In this example, the magnetic element Lr is not integrated into T, making the design of the transformer easier.

Example 3

3. The resonance inductance is the leakage inductance of the transformer T.

5 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 3 of the embodiment of the present invention. The parallel resonant converter shown in FIG. 5 is a parallel connection of two asymmetric half-bridge resonant converters, including the first The switching devices S1, S2 of the first road, the rectifying devices S10, S20 of the first road, the switching devices S3, S4 of the second road, the rectifying devices S30, S40 of the second road, the resonant capacitor Cr shared by the two resonant converters, two The excitation inductances Lm1 and Lm2 of the two-way transformer and the primary and secondary windings of the two-way transformer are magnetically integrated into a pair of magnetic cores to form T. The resonance inductance of the two-way resonant converter is the leakage inductance of the transformer T. The leakage inductance is not shown in Figure 4. Shows. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. In this example, the design of the magnetic integrated transformer T makes production easier, and the cost of the transformer is reduced.

Example 4

1. The topological structure of the resonant converter is: two-way symmetrical half-bridge resonant converter topology;

3. The resonant capacitor is a resonant capacitor group.

6 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 4 of the embodiment of the present invention. The parallel resonant converter shown in FIG. 6 is a parallel connection of two symmetrical half-bridge resonant converters, including the first path The switching devices S1, S2, the first rectifier devices S10, S20, the second switching devices S3, S4, the second rectifier devices S30, S40, the resonance capacitors Cr1, Cr2 shared by the two resonant converters, The resonant inductance Lr shared by the two resonant converters, the excitation inductances Lm1 and Lm2 of the two transformers, and the primary and secondary windings of the two transformers are magnetically integrated to form a magnetic core. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. In this example, the ripple current of the input capacitor is reduced.

Example 5

3. The resonant capacitor is a resonant capacitor group, and two resonant capacitors are connected in parallel with a diode.

Fig. 7 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 5 of the embodiment of the present invention. The parallel resonant converter shown in Fig. 7 is a parallel connection of two symmetrical half-bridge resonant converters, including the first circuit The switching devices S1, S2, the first rectifier devices S10, S20, the second switching devices S3, S4, the second rectifier devices S30, S40, the resonance capacitors Cr1, Cr2 shared by the two resonant converters, The clamping diodes D1 and D2 shared by the two resonant converters, the resonant inductance Lr shared by the two resonant converters, the excitation inductances Lm1, Lm2 of the two transformers and the primary and secondary windings of the two transformers are magnetically integrated into a magnetic core In constitute T. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. Due to the clamping effect of D1 and D2, the topology of this example can realize short-circuit protection, and no additional short-circuit protection strategy is needed.

Example 6

1. The topological structure of the resonant converter is: two-way full-bridge resonant converter topology;

2. The excitation inductance of the two transformers and the primary and secondary windings of the two transformers are magnetically integrated into a pair of magnetic cores to form the first transformer T.

Fig. 8 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 6 of the embodiment of the present invention. The parallel resonant converter shown in Fig. 8 is a parallel connection of two full-bridge resonant converters, including the first Switching devices S1, S2, S5, S6, the first rectifying device S10, S20, the second switching device S3, S4, S7, S8, the second rectifying device S30, S40, shared by the two resonant converters The resonant capacitor Cr, the resonant inductance Lr shared by the two resonant converters, the excitation inductances Lm1 and Lm2 of the two transformers and the primary and secondary windings of the two transformers are magnetically integrated to form T in a pair of magnetic cores. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. The topology of this example is a full-bridge structure, and the ripple current of the input capacitor is reduced, and it is suitable for higher power applications.

Example 7

1. The topological structure of the resonant converter is: two-way three-level half-bridge resonant converter topology;

Fig. 9 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 7 of the embodiment of the present invention. The parallel resonant converter shown in Fig. 9 includes the first switching devices S1, S2, S3, and S4. The rectifier devices S10, S20 of the first road, the voltage dividing capacitors C1, C2 of the first road, the clamping diodes D1, D2 of the first road, the switching devices S5, S6, S7, S8 of the second road, and the rectifier device S30 of the second road , S40, the second voltage divider capacitors C3, C4, the second clamp diodes D3, D4, the resonant capacitor Cr shared by the two resonant converters, the resonant inductor Lr shared by the two resonant converters, and two transformers The excitation inductances Lm1, Lm2 and the primary and secondary windings of the two transformers are magnetically integrated into a pair of magnetic cores to form T. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. The topology of this example is a three-level half-bridge structure, the ripple current of the input capacitor is reduced, and it is suitable for high-voltage input applications.

Example 8

2. Adopt independent resonant inductor and two independent transformers T1 and T2.

Fig. 10 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 8 of the embodiment of the present invention. The parallel resonant converter shown in Fig. 10 is a parallel connection of two asymmetric half-bridge resonant converters, including the first The switching devices S1 and S2 of the first road, the rectifying devices S10 and S20 of the first road, the switching devices S3 and S4 of the second road, the rectifying devices S30 and S40 of the second road, the resonant capacitor Cr shared by the two resonant converters and two The resonant inductance Lr shared by the resonant converters, the excitation inductances Lm1 and Lm2 of the two transformers and the primary and secondary windings of the two transformers respectively constitute two independent transformers T1 and T2. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. This example uses an independent resonant inductor Lr and two independent transformers T1 and T2, and the number of magnetic components is increased.

Example 9

2. Use independent resonant inductors and two independent transformers T1 and T2;

3. Both resonant inductors and resonant capacitors use resonant inductors and resonant capacitors.

11 is a schematic diagram of the equivalent circuit of the parallel resonant converter of Example 8 of the embodiment of the present invention. The parallel resonant converter shown in FIG. 11 includes the first switching devices S1 and S2, and the first rectifying device S10 , S20, the second switching device S3, S4, the second rectifier device S30, S40, the resonant capacitors Cr1 and Cr2 shared by the two resonant converters are connected in parallel, and the resonant inductors Lr1, Lr2 shared by the two resonant converters Connected in parallel, the excitation inductances Lm1 and Lm2 of the two transformers and the primary and secondary windings of the two transformers respectively constitute two independent transformers T1 and T2. The input ends of the two resonant converters are connected in parallel with the DC source Vin; the output ends of the two converters are connected in parallel with the output capacitor Co and the load resistance Ro. This kind of example can conveniently multiply and expand the power of the module power supply, without separately designing resonance parameters and selecting resonance capacitors, resonance inductors, transformers and switching devices for different power supplies.

In summary, with the help of the technical solution of the embodiment of the present invention, the resonant capacitor and the resonant inductor are shared, which solves the problem of non-uniform current in the parallel resonant converter in the prior art, and reduces the number and volume of magnetic components. The power density of the power supply is improved, the core loss of the magnetic element is reduced, the efficiency of the power supply is improved, and the cost of the magnetic element is reduced.

According to an embodiment of the present invention, there is also provided a power supply including the above-mentioned parallel resonant converter. FIG. 12 is a schematic diagram of a power supply according to an embodiment of the present invention. As shown in FIG. 12, the power supply 100 includes a parallel resonant converter 110.

The parallel resonant converter 110 includes at least two parallel resonant converters, wherein at least two parallel resonant converters share a resonant capacitor and a resonant inductor.

In the embodiment of the present invention, the topological structure of the resonant converter 110 may be: asymmetric half-bridge resonant converter topology, symmetrical half-bridge resonant converter topology, full-bridge resonant converter topology, three-level half-bridge resonant Converter topology, or three-level full-bridge resonant converter topology. The resonant converter 110 may be an LLC resonant converter or a series resonant converter.

In addition, in the embodiment of the present invention, the resonant capacitor may be a capacitor or a resonant capacitor group. Similarly, the resonant inductor can be an inductor or a resonant inductor group. In addition, in another example, the resonant inductance may also be the leakage inductance of the second transformer T ₂ .

In addition, in the embodiment of the present invention, in order to reduce the volume and loss of the magnetic element, in one example, the resonant inductor and the transformer of at least two resonant converters are magnetically integrated into a pair of magnetic cores to form the first transformer T ₁ . In another example, the transformers of at least two resonant converters are magnetically integrated into a pair of magnetic cores to form the second transformer T ₂ . When the resonant converter is a symmetrical half-bridge resonant converter topology, the resonant capacitor can also be connected in parallel with a diode.

Specific examples and details of the resonant converter 110 can be understood with reference to the above-mentioned embodiments, and will not be repeated here.

Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present invention can be implemented by a general computing device. They can be concentrated on a single computing device or distributed in a network composed of multiple computing devices. Above, in an embodiment, they can be implemented with program codes executable by a computing device, so that they can be stored in a storage device for execution by the computing device, and in some cases, they can be different from here. The steps shown or described are executed in the order of, or they are respectively fabricated into individual integrated circuit modules, or multiple modules or steps of them are fabricated into a single integrated circuit module to achieve. In this way, the present invention is not limited to any specific combination of hardware and software.

The above description is only the embodiments of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc., made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

A parallel resonant converter includes: at least two parallel resonant converters, wherein the at least two parallel resonant converters share a resonant capacitor and a resonant inductor.
The parallel resonant converter of claim 1, wherein the topological structure of the resonant converter is: an asymmetric half-bridge resonant converter topology, a symmetrical half-bridge resonant converter topology, and a full-bridge resonant converter topology , Three-level half-bridge resonant converter topology, or three-level full-bridge resonant converter topology.
The parallel resonant converter according to claim 1, wherein the resonant converter is an LLC resonant converter or a series resonant converter.
The parallel resonant converter of claim 1, wherein the resonant capacitor is a resonant capacitor group.
3. The parallel resonant converter of claim 1, wherein the resonant inductor is a resonant inductor group.
The parallel resonant converter according to claim 1, wherein the resonant inductor and the transformers of the at least two resonant converters are magnetically integrated into a pair of magnetic cores to form the first transformer T 1 .
The parallel resonant converter according to claim 1, wherein the transformers of the at least two resonant converters are magnetically integrated into a pair of magnetic cores to form a second transformer T 2 .
Parallel resonant converter according to claim 7, wherein said resonant inductance is the leakage inductance of the second transformer T 2.
3. The parallel resonant converter according to claim 2, wherein when the resonant converter is a symmetrical half-bridge resonant converter topology, the resonant capacitor is connected in parallel with a diode.
A power supply comprising the parallel resonant converter according to any one of claims 1-9.