Three-phase AC / DC switching power supply system

Abstract

The utility model discloses a three-phase AC / DC switching power supply system, which relates to the field of power conversion, and is characterized in that a three-phase rectification module is used for carrying out synchronous rectification on three-phase AC input by a three-phase motor and outputting DC; the bus is connected with the three-phase rectifier module and is used for boosting the direct current output by the three-phase alternating current rectifier module; the alternating current and direct current switching module is connected with the bus and is used for switching to a three-phase full-bridge inversion wave-generating control to output alternating current when the alternating current is output, or switching to a BUCK circuit to output direct current when the direct current is output; and the relay is connected with the alternating current and direct current switching module and is used for controlling the output of alternating current or direct current. The AC / DC switching power supply solves the problem that the AC / DC switching power supply provided by the prior art cannot meet the use requirements of three-phase equipment.

Description

Technical Field

[0001] This utility model relates to the field of power conversion, and more specifically, it relates to a three-phase AC / DC switching power supply system. Background Technology

[0002] Currently, in AC / DC output switching applications, such as outdoor power supplies and energy feedback systems for electric vehicles, separate AC output modules and separate DC output modules are used to achieve AC / DC output switching. This method can only achieve one function in the motor field, such as AC output or DC output, and can only meet the needs of single-phase equipment, not three-phase equipment. If two functions are to be integrated, an additional module is required, which increases the size of the entire power system and also leads to disadvantages such as low reuse rate of power devices, complex switching control, and slow output response. Utility Model Content

[0003] The purpose of this invention is to provide a three-phase AC / DC switching power supply system, which solves the problem that the AC / DC switching power supplies provided by current related technologies cannot meet the usage requirements of three-phase equipment.

[0004] The above-mentioned technical objective of this utility model is achieved through the following technical solution:

[0005] This utility model provides a three-phase AC / DC switching power supply system, the system comprising:

[0006] The three-phase rectifier module is used to synchronously rectify the three-phase AC input of a three-phase motor and output DC power.

[0007] The busbar is connected to the three-phase rectifier module and is used to boost the DC power output by the three-phase AC rectifier module.

[0008] An AC / DC switching module, connected to the bus, is used to switch to a three-phase full-bridge inverter waveform control output AC when outputting AC, or to switch to a BUCK circuit output DC when outputting DC.

[0009] A relay, connected to the AC / DC switching module, is used to control the AC or DC output.

[0010] In one implementation, the three-phase rectifier module is a first three-phase full-bridge inverter circuit, which consists of six MOS transistors, wherein the upper and lower MOS transistors form one bridge arm, and the first three-phase full-bridge inverter circuit has a total of three bridge arms.

[0011] In one implementation, the busbar includes three capacitors connected in parallel to the output side of the three-phase rectifier module.

[0012] In one implementation, the AC / DC switching module includes a second three-phase full-bridge inverter circuit and an inductor; wherein the second three-phase full-bridge inverter circuit is composed of six MOSFETs, wherein two MOSFETs are arranged in a bridge arm, and the second three-phase full-bridge inverter circuit has a total of three bridge arms.

[0013] The midpoint of each of the three bridge arms of the second and third phase full-bridge inverter circuit is connected to one end of an inductor, for a total of three inductors.

[0014] In one implementation, during AC output, the first three-phase full-bridge inverter circuit switches its conduction combination every 60 degrees, while the second three-phase full-bridge inverter circuit performs three-phase full-bridge inverter wave generation control to output AC.

[0015] In one implementation, during DC output, each arm of the second three-phase full-bridge inverter circuit forms a BUCK loop, for a total of three BUCK loops; each BUCK loop is controlled by a 120-degree phase difference to achieve three-phase interleaved BUCK.

[0016] In one implementation, the inductor is used as both an AC inverter inductor and a DC energy storage inductor.

[0017] In one implementation, the number of relays is the same as the number of inductors in the AC / DC switching module, with the input terminal of each relay connected to the other end of an inductor.

[0018] In one implementation, the relay includes a DC output terminal and an AC output terminal;

[0019] A capacitor is also connected in parallel between the AC output terminals of the relay;

[0020] The DC output terminal of the relay is connected to a filter circuit.

[0021] In one implementation, the filter circuit is a π-type filter circuit.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] In the three-phase AC / DC switching power supply system provided by this utility model, the front-end topology adopts a conventional three-phase full-bridge topology, and the rear-end adopts the same three-phase full-bridge topology. The output full-bridge circuit is multiplexed and used simultaneously as a full-bridge inverter and BUCK circuit topology. The output inductor is also multiplexed, with an inductor connected to the midpoint of each of the three arms of the full-bridge circuit. The output section uses relays for output control. The advantage of this approach is that it integrates AC and DC outputs into a single module. Furthermore, the power devices and output inductors can be reused, requiring only three additional relays. This not only reduces the size but also increases the reuse rate of power devices, simplifies control, and improves the response speed of the output AC or DC. Therefore, the novel power supply system provided by this utility model not only solves the needs of three-phase AC users but also meets the needs of DC users, improving the module's integration. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0025] Figure 1 A schematic block diagram of a three-phase AC / DC switching power supply system provided in this embodiment of the present invention;

[0026] Figure 2 A schematic diagram of the circuit structure of a three-phase AC / DC switching power supply system provided in an embodiment of this utility model. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0028] It should be noted that the terms "comprising" or "may include" used in the various embodiments of this application indicate the presence of the claimed function, operation, or element, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in the various embodiments of this application, the terms "comprising," "having," and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0029] It should be understood that terms such as "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] Please refer to Figure 1 , Figure 1 The schematic block diagram of the three-phase AC / DC switching power supply system provided in the embodiment of this utility model is as follows: Figure 1 As shown, the system includes:

[0031] The three-phase rectifier module is used to synchronously rectify the three-phase AC input of a three-phase motor and output DC power.

[0032] The busbar is connected to the three-phase rectifier module and is used to boost the DC power output by the three-phase AC rectifier module.

[0033] An AC / DC switching module, connected to the bus, is used to switch to a three-phase full-bridge inverter waveform control output AC when outputting AC, or to switch to a BUCK circuit output DC when outputting DC.

[0034] A relay, connected to the AC / DC switching module, is used to control the AC or DC output.

[0035] Specifically, please refer to Figure 2 The diagram shows that the three-phase rectifier module is a first three-phase full-bridge inverter circuit. This first three-phase full-bridge inverter circuit consists of six MOSFETs, with each bridge arm composed of two MOSFETs connected in parallel. The first three-phase full-bridge inverter circuit has three bridge arms. The busbar includes three capacitors connected in parallel to the output side of the three-phase rectifier module.

[0036] The AC / DC switching module includes a second three-phase full-bridge inverter circuit and inductors; the second three-phase full-bridge inverter circuit consists of six MOSFETs, with each bridge arm consisting of two MOSFETs, one upper and one lower, for a total of three bridge arms; the midpoint of each of the three bridge arms of the second three-phase full-bridge inverter circuit is connected to one end of an inductor, for a total of three inductors.

[0037] When the AC / DC switching module is outputting AC, the first three-phase full-bridge inverter circuit switches its conduction combination every 60 degrees, while the second three-phase full-bridge inverter circuit performs three-phase full-bridge inverter wave generation control to output AC.

[0038] When the AC / DC switching module is outputting DC, each arm of the second three-phase full-bridge inverter circuit forms a BUCK loop, for a total of three BUCK loops; each BUCK loop is controlled by a 120-degree phase difference to achieve three-phase interleaved BUCK.

[0039] The inductor is used as an AC inverter inductor and a DC energy storage inductor.

[0040] The number of relays is the same as the number of inductors in the AC / DC switching module, and the input terminal of each relay is connected to the other end of an inductor.

[0041] The relay includes a DC output terminal and an AC output terminal; a capacitor is connected in parallel between the AC output terminals of the relay; and a filter circuit is connected to the DC output terminal of the relay. Specifically, the filter circuit is a π-type filter circuit.

[0042] Specifically, in Figure 2 In the circuit, the three-phase rectifier module is the first three-phase full-bridge inverter circuit composed of 6 MOSFETs (i.e., MOSFETs Q1-Q6). Capacitor C2 is the bus capacitor, and capacitors C1 and C3 are metal film capacitors. These three capacitors constitute the bus section, and capacitors C1, C2, and C3 are connected in parallel in sequence on the input of the three-phase rectifier module.

[0043] For the second and third phase full-bridge inverter circuit of the AC / DC switching module, it contains six MOSFETs (Q7-Q12) as the subsequent topology. Inductors L1, L2, and L3 are shared by the AC-side inverter inductor and the DC-side BUCK inductor.

[0044] Relays RLY1, RLY2, and RLY3 serve as output relays, capacitors C4, C5, and C6 are inverter output capacitors, and capacitors C7, C8, and inductor L4 form a π-type filter circuit to reduce DC output ripple.

[0045] When AC output is enabled, the six MOSFETs Q1-Q6 conduct in pairs, performing three-phase full-bridge rectification, which increases the bus voltage. During AC output, the six power devices Q7-Q12 perform three-phase full-bridge inverter control. The first three-phase full-bridge inverter circuit cycles through MOSFETs Q1 → Q2 → Q3 → Q4 → Q5 → Q6, switching the conduction combination every 60° between phases. After LC filtering by the output inductor and capacitor (here, LC filtering refers to the filter circuit for phase A output composed of capacitor C4 and inductor L1; the same applies to phases B and C), the AC voltage is obtained.

[0046] When outputting DC, MOSFETs Q7 and Q10 form a BUCK circuit. When MOSFET Q7 is turned on, inductor L1 begins to store energy and the current increases, charging the output capacitor while providing energy to the load. Because it is a synchronous BUCK, when MOSFET Q7 is turned off, since the inductor current cannot change abruptly, MOSFET Q10 turns on, and freewheeling occurs through its internal circuitry. MOSFETs Q8 and Q11 form a second BUCK circuit, and MOSFETs Q9 and Q12 form a third BUCK circuit, operating on the same principle as the MOSFETs Q7 and Q10 BUCK circuit. All three BUCK circuits can operate simultaneously. In the power supply system provided in this embodiment, the three BUCK circuits are controlled with a 120° phase difference, achieving three-phase interleaved BUCK. Compared to two-phase interleaved BUCK, three-phase BUCK better improves DC output ripple. Furthermore, because multiplexed AC inductors are used, the size is reduced, achieving high efficiency and high reliability of the power supply system.

[0047] In the three-phase AC / DC switching power supply system provided by this utility model, the front-end topology adopts a conventional three-phase full-bridge topology, and the rear-end adopts the same three-phase full-bridge topology. The output full-bridge circuit is multiplexed and used simultaneously as a full-bridge inverter and BUCK circuit topology. The output inductor is also multiplexed, with an inductor connected to the midpoint of each of the three arms of the full-bridge circuit. The output section uses relays for output control. The advantage of this approach is that it integrates AC and DC outputs into a single module. Furthermore, the power devices and output inductors can be reused, requiring only three additional relays. This not only reduces the size but also increases the reuse rate of power devices, simplifies control, and improves the response speed of the output AC or DC. Therefore, the novel power supply system provided by this utility model not only solves the needs of three-phase AC users but also meets the needs of DC users, improving the module's integration.

[0048] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A three-phase AC / DC switching power supply system, characterized in that, The system includes: The three-phase rectifier module is used to synchronously rectify the three-phase AC input of a three-phase motor and output DC power. The busbar is connected to the three-phase rectifier module and is used to boost the DC power output by the three-phase AC rectifier module. An AC / DC switching module, connected to the bus, is used to switch to a three-phase full-bridge inverter waveform control output AC when outputting AC, or to switch to a BUCK circuit output DC when outputting DC. A relay, connected to the AC / DC switching module, is used to control the AC or DC output.

2. The three-phase AC / DC switching power supply system according to claim 1, characterized in that, The three-phase rectifier module is a first three-phase full-bridge inverter circuit, which consists of six MOSFETs. Each bridge arm is composed of two MOSFETs, one upper and one lower. The first three-phase full-bridge inverter circuit has a total of three bridge arms.

3. A three-phase AC / DC switching power supply system according to claim 2, characterized in that, The busbar includes three capacitors connected in parallel on the output side of the three-phase rectifier module.

4. A three-phase AC / DC switching power supply system according to claim 3, characterized in that, The AC / DC switching module includes a second three-phase full-bridge inverter circuit and an inductor; wherein the second three-phase full-bridge inverter circuit is composed of six MOSFETs, wherein the upper and lower MOSFETs form a bridge arm, and the second three-phase full-bridge inverter circuit has a total of three bridge arms; The midpoint of each of the three bridge arms of the second and third phase full-bridge inverter circuit is connected to one end of an inductor, for a total of three inductors.

5. A three-phase AC / DC switching power supply system according to claim 4, characterized in that, During AC output, the first three-phase full-bridge inverter circuit switches its conduction combination every 60 degrees, while the second three-phase full-bridge inverter circuit performs three-phase full-bridge inverter wave generation control to output AC.

6. A three-phase AC / DC switching power supply system according to claim 4, characterized in that, In DC output mode, each arm of the second and third phase full-bridge inverter circuit forms a BUCK loop, for a total of three BUCK loops; each BUCK loop is controlled by a 120-degree phase difference to achieve three-phase interleaved BUCK.

7. A three-phase AC / DC switching power supply system according to claim 4, characterized in that, The inductor is used as an AC inverter inductor and a DC energy storage inductor.

8. A three-phase AC / DC switching power supply system according to claim 4, characterized in that, The number of relays is the same as the number of inductors in the AC / DC switching module, and the input terminal of each relay is connected to the other end of an inductor.

9. A three-phase AC / DC switching power supply system according to claim 1, characterized in that, The relay includes a DC output terminal and an AC output terminal; A capacitor is also connected in parallel between the AC output terminals of the relay; The DC output terminal of the relay is connected to a filter circuit.

10. A three-phase AC / DC switching power supply system according to claim 9, characterized in that, The filter circuit is a π-type filter circuit.

Images