CN110890841A

CN110890841A - Multi-transformer combined topology circuit and LLC resonant switching power supply

Info

Publication number: CN110890841A
Application number: CN201811045795.2A
Authority: CN
Inventors: 钟延煌; 蔡智勇
Original assignee: Shenzhen Yinghe Technology Co Ltd
Current assignee: Shenzhen Yinghe Technology Co Ltd
Priority date: 2018-09-07
Filing date: 2018-09-07
Publication date: 2020-03-17

Abstract

The application belongs to the technical field of switching power supplies, and relates to a multi-transformer combined topology circuit and an LLC resonant switching power supply. The multi-transformer combined topology circuit comprises: the half-bridge topology comprises an upper arm and a lower arm of a half-bridge topology, an LLC series resonant circuit, a transformer bank and an output rectifying and filtering circuit; the upper and lower arms of the half-bridge topology are electrically connected with the LLC series resonant circuit, the LLC series resonant circuit is electrically connected with the transformer bank, and the transformer bank is electrically connected with the output rectifying and filtering circuit; the upper arm and the lower arm of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtration; the upper and lower arms of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; and the upper and lower arms of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank. Which is beneficial to solving the defects of a single high-power transformer.

Description

Multi-transformer combined topology circuit and LLC resonant switching power supply

Technical Field

The application belongs to the technical field of switching power supplies, and relates to a multi-transformer combined topology circuit and an LLC resonant switching power supply.

Background

At present, a single LLC resonant switching power supply usually only uses one main power transformer when the output power is large.

During the research of the present application, the inventor finds that the single LLC resonant switching power supply in the prior art has the following disadvantages: (1) the loss of a single high-power transformer is concentrated in one transformer, the heat dissipation area is small, and the temperature of the transformer is overhigh; (2) a single high-power transformer is difficult to process, and the high-power transformer generally needs to pass large current, so the wire diameter is thick and the winding is difficult; (3) the high-power transformer is too heavy and is not beneficial to large-batch assembly line operation.

Disclosure of Invention

The embodiment of the application discloses a multi-transformer combined topology circuit, an LLC resonant switching power supply and an electronic device, and aims to solve any one of the problems in the prior art mentioned in the background art.

One or more embodiments of the present application disclose a multi-transformer combined topology circuit. The multi-transformer combined topology circuit comprises: the half-bridge topology comprises an upper arm and a lower arm of a half-bridge topology, an LLC series resonant circuit, a transformer bank and an output rectifying and filtering circuit; the upper and lower arms of the half-bridge topology are electrically connected with the LLC series resonant circuit, the LLC series resonant circuit is electrically connected with the transformer bank, and the transformer bank is electrically connected with the output rectifying and filtering circuit; the upper arm and the lower arm of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtration; the upper and lower arms of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank; and the LLC series resonant circuit and the primary side self-inductance of the transformer bank form an LLC main energy loop.

In one or more embodiments of the present application, the upper and lower arms of the half-bridge topology are formed by a main switching power transistor M1 and a main switching power transistor M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source of the main switch power tube M2 is grounded.

In one or more embodiments of the present application, the LLC series-resonant circuit includes a resonant capacitor C1 and an inductor L1; one end of the resonant capacitor C1 is connected between the source of the main switching power transistor M1 and the drain of the main switching power transistor M2, the other end of the resonant capacitor C1 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the first transformer of the transformer bank.

In one or more embodiments of the present application, the transformer bank is formed by connecting n transformers in series, where n is an integer greater than or equal to 2; the No. 1 terminal of a first transformer T1 of the transformer bank is connected with the inductor L1; the No. 2 terminal of the nth transformer of the transformer bank is grounded; the primary coils of all transformers are connected in series; the No. 4 terminals of the secondary coils of all transformers are connected in series and finally grounded.

In one or more embodiments of the present application, the output rectifying and filtering circuit includes 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer bank are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded.

One or more embodiments of the present application disclose an LLC resonant switching power supply. The LLC resonance switch power supply comprises: the multi-transformer combined topology circuit comprises a multi-transformer combined topology circuit, a control unit, a rectifier bridge stack DB1 and a polar capacitor E2; the multi-transformer combined topology circuit comprises: the half-bridge topology comprises an upper arm and a lower arm of a half-bridge topology, an LLC series resonant circuit, a transformer bank and an output rectifying and filtering circuit; the upper and lower arms of the half-bridge topology are electrically connected with the LLC series resonant circuit, the LLC series resonant circuit is electrically connected with the transformer bank, and the transformer bank is electrically connected with the output rectifying and filtering circuit; the upper arm and the lower arm of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtration; the upper and lower arms of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank; the LLC series resonant circuit and the primary side self-inductance of the transformer bank form an LLC main energy loop; the control unit is used for outputting a first pulse width modulation signal and a second pulse width modulation signal to the upper arm and the lower arm of the half-bridge topology; the rectifier bridge stack DB1 is connected to the upper and lower arms of the half-bridge topology and is used for rectifying and filtering the single-phase power or the three-phase power to obtain direct current which is input into the upper and lower arms of the half-bridge topology; the anode of the polar capacitor E2 is connected to the upper and lower arms of the half-bridge topology, and the cathode of the polar capacitor E2 is grounded.

In one or more embodiments of the present application, the upper and lower arms of the half-bridge topology are formed by a main switching power transistor M1 and a main switching power transistor M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source electrode of the main switching power tube M2 is grounded; the direct current positive electrode of the rectifier bridge stack DB1 is connected with the drain electrode of the main switch power tube M1, and the direct current negative electrode of the rectifier bridge stack DB1 is grounded; the polarity capacitor E2 is connected between the direct current positive electrode and the direct current negative electrode of the rectifier bridge stack DB1, the positive electrode of the polarity capacitor E2 is connected with the drain electrode of the main switch power tube M1, and the negative electrode of the polarity capacitor E2 is grounded.

In one or more embodiments of the present application, the output rectifying and filtering circuit includes 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer bank are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded; the resistor R1 and the resistor R2 are connected in series and then connected in parallel at two ends of the polar capacitor E1; an output voltage sampling terminal of the control unit is connected between the resistor R1 and the resistor R2.

One or more embodiments of the present application disclose an electronic device, on which any one of the LLC resonant switching power supplies described above is provided.

Compared with the prior art, the technical scheme disclosed by the application mainly has the following beneficial effects:

in an embodiment of the present application, the multi-transformer combined topology circuit includes: the half-bridge topology comprises an upper arm and a lower arm of a half-bridge topology, an LLC series resonant circuit, a transformer bank and an output rectifying and filtering circuit. The upper arm and the lower arm of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtration; converting the direct current of the single-phase power or the three-phase power after rectification and filtration into a high-frequency square wave through the upper and lower arms of the half-bridge topology; receiving a first pulse width modulation signal and a second pulse width modulation signal through the upper arm and the lower arm of the half-bridge topology, and controlling the frequency of the high-frequency square wave so as to regulate the voltage and the power output by the transformer bank; and an LLC main energy loop is formed by the LLC series resonant circuit and the primary side self-inductance of the transformer bank. In the embodiments of the present application, the current through the primary side of each transformer of the bank is equal, as is the current flowing from the secondary side of each transformer of the bank. Each transformer of the transformer bank has uniform current and uniform heat generation. Therefore, the multi-transformer combined topology circuit can be suitable for the condition of high power, and the heat is uniformly diffused. In the embodiment of the application, the multi-transformer combined topological circuit is beneficial to solving the defects existing in a single high-power transformer.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

FIG. 1 is a schematic diagram of a multi-transformer combined topology according to an embodiment of the present application;

FIG. 2 is a specific structure diagram of a multi-transformer combined topology circuit according to an embodiment of the present application;

FIG. 3 is a graph of the conductance of the LLC main energy loop output power versus frequency in an embodiment of the application;

fig. 4 is a specific structural diagram of an LLC resonant switching power supply in an embodiment of the present application.

Description of reference numerals:

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

At present, a single LLC resonant switching power supply usually only uses one main power transformer when the output power is large. During the research of the present application, the inventor finds that the single LLC resonant switching power supply in the prior art has the following disadvantages: (1) the loss of a single high-power transformer is concentrated in one transformer, the heat dissipation area is small, and the temperature of the transformer is overhigh; (2) a single high-power transformer is difficult to process, and the high-power transformer generally needs to pass large current, so the wire diameter is thick and the winding is difficult; (3) the high-power transformer is too heavy and is not beneficial to large-batch assembly line operation.

One embodiment of the present application discloses a multi-transformer combined topology circuit.

Referring to fig. 1, a schematic diagram of a multi-transformer combined topology circuit according to an embodiment of the present application is shown.

As illustrated in fig. 1, the multi-transformer combined topology circuit includes: the half-bridge topology comprises upper and lower arms 10, an LLC series resonant circuit 20, a transformer bank 30 and an output rectifying and filtering circuit 40; the upper and

lower arms

10 and 20 of the half-bridge topology are electrically connected to the LLC series resonant circuit 20, the LLC series resonant circuit 20 is electrically connected to the transformer bank 30, and the transformer bank 30 is electrically connected to the output rectifying and filtering circuit 40.

The upper arm and the lower arm 10 of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtering; the upper and lower arms 10 of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms 10 of the half-bridge topology receive the first pulse width modulation signal and the second pulse width modulation signal, and control the frequency of the high-frequency square wave, thereby adjusting the voltage and power output by the transformer bank 30.

The LLC series resonant circuit 20 and the primary side inductance of the transformer bank 30 form an LLC main energy loop.

In an embodiment of the present application, the multi-transformer combined topology circuit includes: upper and lower arms 10 of half-bridge topology, LLC series resonant circuit 20, transformer bank 30 and output rectifying and filtering circuit 40. The direct current of single-phase electricity or three-phase electricity after rectification and filtration is accessed through the upper and lower arms 10 of the half-bridge topology; converting the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave through the upper and lower arms 10 of the half-bridge topology; receiving a first pulse width modulation signal and a second pulse width modulation signal through the upper and lower arms 10 of the half-bridge topology, and controlling the frequency of the high-frequency square wave, thereby adjusting the voltage and power output by the transformer bank 30; the primary side self-inductance of the transformer bank 30 and the LLC series resonant circuit 20 form an LLC main energy loop. In the embodiment of the present application, the primary side of each transformer of the transformer bank 30 has the same current, and the secondary side of each transformer of the transformer bank 30 has the same current. Each transformer of the transformer bank 30 is current-sharing and heat-generating balanced. Therefore, the multi-transformer combined topology circuit can be suitable for the condition of high power, and the heat is uniformly diffused. In the embodiment of the application, the multi-transformer combined topological circuit is beneficial to solving the defects existing in a single high-power transformer.

Referring to fig. 2, a specific structure diagram of a multi-transformer combined topology circuit according to an embodiment of the present application is shown.

As illustrated in fig. 2, the upper and lower arms 10 of the half-bridge topology are composed of a main switching power transistor M1 and a main switching power transistor M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source of the main switch power tube M2 is grounded.

With continued reference to fig. 2, the LLC series resonant circuit 20 includes a resonant capacitor C1 and an inductor L1; one end of the resonant capacitor C1 is connected between the source of the main switching power transistor M1 and the drain of the main switching power transistor M2, the other end of the resonant capacitor C1 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the first transformer of the transformer bank 30.

With reference to fig. 2, the transformer bank 30 is formed by connecting n transformers in series, where n is an integer greater than or equal to 2; the terminal 1 of the first transformer T1 of the transformer bank 30 is connected to the inductor L1; the terminal No. 2 of the nth transformer of the transformer bank 30 is grounded; the primary coils of all transformers are connected in series; the No. 4 terminals of the secondary coils of all transformers are connected in series and finally grounded.

With continued reference to fig. 2, the output rectifying-filtering circuit 40 includes 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer group 30 are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded.

Referring to fig. 3, a graph of conduction of LLC main energy loop output power versus frequency is shown in an embodiment of the present application. Fig. 3 is intended to qualitatively illustrate the conduction characteristics of the LLC main energy loop output power, without quantitative significance.

The upper and lower arms 10 of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave. Generally, the higher the frequency of the high-frequency square wave, the lower the voltage output by the transformer bank (30).

As can be seen from FIG. 3, each set of specific LLC parameter curves has a peak a. The peak a corresponds to a frequency f:

wherein L is the inductance of the inductor L1, T1-L to Tn-L are the self-inductance of the primary side of the transformer bank (30), RL is the resistance value of the load resistor equivalent to the primary side of the transformer bank (30), and C is the capacitance value of the resonant capacitor C1.

N1 is the number of primary turns of a single transformer, since N transformers are connected in series, there is N1 × N; n2 is the half-bridge side turn number of each transformer secondary side becauseThe mode of the middle tap really plays a calculation role in half of the total number of turns; rf is a load resistance value.

(T1-L + T2-L +. cndot. L) | | RL shows that the self-inductance of the transformer bank (30) is added and then connected with RL in parallel, and the calculation relationship is a complex number.

In the embodiment of the present application, a high frequency and a large current flow through the resonant capacitor C1 during operation, so the quality requirement of the resonant capacitor C1 is particularly high. The MMKP82 CBB capacitor is recommended, or a plurality of capacitors are used in parallel.

An embodiment of the present application discloses an LLC resonant switching power supply.

Please refer to fig. 1 and fig. 4, wherein fig. 4 is a specific structural diagram of an LLC resonant switching power supply according to an embodiment of the present application.

As illustrated in fig. 1 and 4, the LLC resonant switching power supply includes: the multi-transformer combined topology circuit comprises a multi-transformer combined topology circuit, a control unit, a rectifier bridge stack DB1 and a polar capacitor E2; the multi-transformer combined topology circuit comprises: the half-bridge topology comprises upper and lower arms 10, an LLC series resonant circuit 20, a transformer bank 30 and an output rectifying and filtering circuit 40; the upper and lower arms 10 and 10 of the half-bridge topology are electrically connected with the LLC series resonant circuit 20, the LLC series resonant circuit 20 is electrically connected with the transformer bank 30, and the transformer bank 30 is electrically connected with the output rectifying and filtering circuit 40; the upper arm and the lower arm 10 of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtering; the upper and lower arms 10 of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms 10 of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank 30; the LLC series resonant circuit 20 and the primary side self-inductance of the transformer bank 30 form an LLC main energy loop; the control unit is used for outputting a first pulse width modulation signal and a second pulse width modulation signal to the upper and lower arms 10 of the half-bridge topology; the rectifier bridge stack DB1 is connected to the upper and lower arms 10 of the half-bridge topology and is used for rectifying and filtering the single-phase power or the three-phase power to obtain direct current which is input into the upper and lower arms 10 of the half-bridge topology; the anode of the polar capacitor E2 is connected to the upper and lower arms 10 of the half-bridge topology, and the cathode of the polar capacitor E2 is grounded.

With continued reference to fig. 1 and 4, the upper and lower arms 10 of the half-bridge topology are formed by a main switching power transistor M1 and a main switching power transistor M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source electrode of the main switching power tube M2 is grounded;

with continued reference to fig. 1 and 4, the dc positive terminal of the bridge rectifier DB1 is connected to the drain of the main switching power transistor M1, and the dc negative terminal of the bridge rectifier DB1 is grounded; the polarity capacitor E2 is connected between the direct current positive electrode and the direct current negative electrode of the rectifier bridge stack DB1, the positive electrode of the polarity capacitor E2 is connected with the drain electrode of the main switch power tube M1, and the negative electrode of the polarity capacitor E2 is grounded.

With continued reference to fig. 1 and 4, the LLC series resonant circuit 20 includes a resonant capacitor C1 and an inductor L1; one end of the resonant capacitor C1 is connected between the source of the main switching power transistor M1 and the drain of the main switching power transistor M2, the other end of the resonant capacitor C1 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the first transformer of the transformer bank 30.

With continued reference to fig. 1 and 4, the transformer bank 30 is formed by connecting n transformers in series, where n is an integer greater than or equal to 2; the terminal 1 of the first transformer T1 of the transformer bank 30 is connected to the inductor L1; the terminal No. 2 of the nth transformer of the transformer bank 30 is grounded; the primary coils of all transformers are connected in series; the No. 4 terminals of the secondary coils of all transformers are connected in series and finally grounded.

With continued reference to fig. 1 and 4, the output rectifying-filtering circuit 40 includes 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer group 30 are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded; the resistor R1 and the resistor R2 are connected in series and then connected in parallel at two ends of the polar capacitor E1; an output voltage sampling terminal of the control unit is connected between the resistor R1 and the resistor R2.

In the embodiment of the present application, the frequency of the high frequency square wave allowed by the control unit should be slightly higher than the peak value a.

An embodiment of the present application discloses an electronic device.

Please refer to fig. 1 to fig. 4. And the electronic equipment is provided with an LLC resonance switching power supply. The LLC resonance switch power supply comprises: the multi-transformer combined topology circuit comprises a multi-transformer combined topology circuit, a control unit, a rectifier bridge stack DB1 and a polar capacitor E2. The multi-transformer combined topology circuit comprises: the half-bridge topology comprises upper and lower arms 10, an LLC series resonant circuit 20, a transformer bank 30 and an output rectifying and filtering circuit 40; the upper and

lower arms

10 and 10 of the half-bridge topology are electrically connected with the LLC series resonant circuit 20, the LLC series resonant circuit 20 is electrically connected with the transformer bank 30, and the transformer bank 30 is electrically connected with the output rectifying and filtering circuit 40; the upper arm and the lower arm 10 of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtering; the upper and lower arms 10 of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms 10 of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank 30; the LLC series resonant circuit 20 and the primary side inductance of the transformer bank 30 form an LLC main energy loop. The control unit is used for outputting a first pulse width modulation signal and a second pulse width modulation signal to the upper and lower arms 10 of the half-bridge topology; the rectifier bridge stack DB1 is connected to the upper and lower arms 10 of the half-bridge topology and is used for rectifying and filtering the single-phase power or the three-phase power to obtain direct current which is input into the upper and lower arms 10 of the half-bridge topology; the anode of the polar capacitor E2 is connected to the upper and lower arms 10 of the half-bridge topology, and the cathode of the polar capacitor E2 is grounded.

Further, the upper and lower arms 10 of the half-bridge topology are composed of a main switching power tube M1 and a main switching power tube M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source of the main switch power tube M2 is grounded.

The direct current positive electrode of the rectifier bridge stack DB1 is connected with the drain electrode of the main switch power tube M1, and the direct current negative electrode of the rectifier bridge stack DB1 is grounded; the polarity capacitor E2 is connected between the direct current positive electrode and the direct current negative electrode of the rectifier bridge stack DB1, the positive electrode of the polarity capacitor E2 is connected with the drain electrode of the main switch power tube M1, and the negative electrode of the polarity capacitor E2 is grounded.

Further, the LLC series-resonant circuit 20 includes a resonant capacitor C1 and an inductor L1; one end of the resonant capacitor C1 is connected between the source of the main switching power transistor M1 and the drain of the main switching power transistor M2, the other end of the resonant capacitor C1 is connected to one end of the inductor L1, and the other end of the inductor L1 is connected to the first transformer of the transformer bank 30.

Further, the transformer bank 30 is formed by connecting n transformers in series, where n is an integer greater than or equal to 2; the terminal 1 of the first transformer T1 of the transformer bank 30 is connected to the inductor L1; the terminal No. 2 of the nth transformer of the transformer bank 30 is grounded; the primary coils of all transformers are connected in series; the No. 4 terminals of the secondary coils of all transformers are connected in series and finally grounded.

Further, the output rectifying and filtering circuit 40 includes 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer group 30 are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded; the resistor R1 and the resistor R2 are connected in series and then connected in parallel at two ends of the polar capacitor E1; an output voltage sampling terminal of the control unit is connected between the resistor R1 and the resistor R2.

When the techniques in the various embodiments described above are implemented using software, the computer instructions and/or data to implement the various embodiments described above may be stored on a computer-readable medium or transmitted as one or more instructions or code on a readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that a computer can store. Taking this as an example but not limiting: computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Further, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.

Finally, it should be noted that: the above examples are only for illustrating the technical solutions of the present application, and are not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. And such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A multi-transformer combined topology circuit, comprising: the power supply comprises a half-bridge topology upper and lower arm (10), an LLC series resonance circuit (20), a transformer bank (30) and an output rectifying and filtering circuit (40); wherein the upper and lower arms (10) of the half-bridge topology are electrically connected with the LLC series resonant circuit (20), the LLC series resonant circuit (20) is electrically connected with the transformer bank (30), and the transformer bank (30) is electrically connected with the output rectifying and filtering circuit (40);

the upper and lower arms (10) of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtering; the upper and lower arms (10) of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms (10) of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank (30);

and the LLC series resonant circuit (20) and the primary side self-inductance of the transformer bank (30) form an LLC main energy loop.

2. The multi-transformer combined topology circuit according to claim 1, wherein the upper and lower arms (10) of the half-bridge topology are composed of a main switching power transistor M1 and a main switching power transistor M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source of the main switch power tube M2 is grounded.

3. The multi-transformer combined topology circuit according to claim 2, wherein the LLC series resonant circuit (20) comprises a resonant capacitor C1 and an inductor L1; one end of the resonant capacitor C1 is connected between the source of the main switching power tube M1 and the drain of the main switching power tube M2, the other end of the resonant capacitor C1 is connected with one end of the inductor L1, and the other end of the inductor L1 is connected with the first transformer of the transformer bank (30).

4. The multi-transformer combined topology circuit according to claim 3, wherein the transformer bank (30) is formed by connecting n transformers in series, n being an integer greater than or equal to 2; the No. 1 terminal of a first transformer T1 of the transformer bank (30) is connected with the inductor L1; the No. 2 terminal of the nth transformer of the transformer bank (30) is grounded; the primary coils of all transformers are connected in series; the No. 4 terminals of the secondary coils of all transformers are connected in series and finally grounded.

5. The multi-transformer combined topology circuit according to claim 4, wherein the output rectifying and filtering circuit (40) comprises 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer group (30) are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded.

6. An LLC resonant switching power supply, comprising: the multi-transformer combined topology circuit comprises a multi-transformer combined topology circuit, a control unit, a rectifier bridge stack DB1 and a polar capacitor E2;

the multi-transformer combined topology circuit comprises: the power supply comprises a half-bridge topology upper and lower arm (10), an LLC series resonance circuit (20), a transformer bank (30) and an output rectifying and filtering circuit (40); wherein the upper and lower arms (10) of the half-bridge topology are electrically connected with the LLC series resonant circuit (20), the LLC series resonant circuit (20) is electrically connected with the transformer bank (30), and the transformer bank (30) is electrically connected with the output rectifying and filtering circuit (40); the upper and lower arms (10) of the half-bridge topology are connected with direct current of single-phase electricity or three-phase electricity after rectification and filtering; the upper and lower arms (10) of the half-bridge topology convert the direct current of the single-phase or three-phase power after rectification and filtration into a high-frequency square wave; the upper and lower arms (10) of the half-bridge topology receive a first pulse width modulation signal and a second pulse width modulation signal, and control the frequency of the high-frequency square wave, so as to adjust the voltage and power output by the transformer bank (30); the LLC series resonance circuit (20) and the primary side self-inductance of the transformer bank (30) form an LLC main energy loop;

the control unit is used for outputting a first pulse width modulation signal and a second pulse width modulation signal to the upper and lower arms (10) of the half-bridge topology; the rectifier bridge stack DB1 is connected to the upper and lower arms (10) of the half-bridge topology and used for rectifying and filtering the single-phase power or the three-phase power to obtain direct current which is input into the upper and lower arms (10) of the half-bridge topology; the anode of the polar capacitor E2 is connected to the upper arm and the lower arm (10) of the half-bridge topology, and the cathode of the polar capacitor E2 is grounded.

7. LLC resonant switching power supply according to claim 6, characterized in that the half-bridge topology upper and lower arms (10) are constituted by a main switching power transistor M1 and a main switching power transistor M2; the grid electrode of the main switching power tube M1 receives the first pulse width modulation signal, the grid electrode of the main switching power tube M2 receives the second pulse width modulation signal, the drain electrode of the main switching power tube M1 receives the direct current of the single-phase or three-phase power after rectification and filtration, and the source electrode of the main switching power tube M1 is connected with the drain electrode of the main switching power tube M2; the source electrode of the main switching power tube M2 is grounded;

8. LLC resonant switching power supply according to claim 7, characterized in that the LLC series resonant circuit (20) comprises a resonant capacitor C1 and an inductor L1; one end of the resonant capacitor C1 is connected between the source of the main switching power tube M1 and the drain of the main switching power tube M2, the other end of the resonant capacitor C1 is connected with one end of the inductor L1, and the other end of the inductor L1 is connected with the first transformer of the transformer bank (30).

9. LLC resonant switching power supply according to claim 8, characterized in that said transformer bank (30) is formed by n transformers connected in series, n being an integer greater than or equal to 2; the No. 1 terminal of a first transformer T1 of the transformer bank (30) is connected with the inductor L1; the No. 2 terminal of the nth transformer of the transformer bank (30) is grounded; the primary coils of all transformers are connected in series; the No. 4 terminals of the secondary coils of all transformers are connected in series and finally grounded.

10. The LLC resonant switching power supply of claim 9, wherein the output rectifying-filtering circuit (40) includes 2n diodes and a polar capacitor E1; the No. 3 terminal and the No. 5 terminal of each transformer of the transformer group (30) are respectively connected with the anode of a diode; the cathodes of the 2n diodes are connected with the anode of the polar capacitor E1, and the cathode of the polar capacitor E1 is grounded;

the resistor R1 and the resistor R2 are connected in series and then connected in parallel at two ends of the polar capacitor E1; an output voltage sampling terminal of the control unit is connected between the resistor R1 and the resistor R2.