Novel bidirectional AC / DC integrated switching power supply structure

Abstract

The utility model relates to a novel bidirectional AC / DC integrated switching power supply structure, and the preceding stage of the power supply structure comprises six MOS tubes, namely an MOS tube Q1, an MOS tube Q2, an MOS tube Q3, an MOS tube Q4, an MOS tube Q5, and an MOS tube Q6. According to the utility model, the conventional design thought is broken, and a novel circuit form is adopted. In a power supply system, a conventional three-phase full-bridge topology is adopted as a preceding-stage topology, an output full-bridge circuit is multiplexed and used as a full-bridge inverter and a BUCK topology at the same time, an output inductor is also multiplexed, a midpoint of each of two bridge arms is connected with one, and an output part adopts a relay for output control; the beneficial effects are that AC output and DC output are integrated in one module, the power tube and the output inductor can be multiplexed, and only two relays need to be added, so that the size of the module is reduced, the multiplexing rate of a power device is increased, the cost is reduced, and the control is relatively simple; and the corresponding output speed is also improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power conversion, specifically a novel bidirectional AC / DC integrated switching power supply structure, which is widely used in outdoor power supplies and energy feedback systems of electric vehicles. Background Art

[0002] In bidirectional AC / DC switching power supply applications, the current market usage is to use separate unidirectional AC output modules and separate unidirectional DC output modules. This application technology is very mature in the motor field, but it can only achieve one function and cannot be reversed.

[0003] For example, the document with publication number CN110556825A discloses an intelligent AC / DC integrated power supply system. Through a bidirectional inverter and a battery pack, when the two input AC power sources are cut off, the battery module supplies power to the inverter power panel, DC charging power panel, and communication power panel, thereby realizing the integration of the DC operating power supply system, the communication power supply system, and the AC operating power supply system, saving equipment resources.

[0004] If you want to integrate both DC and AC functions, you need to add an additional module, which will result in disadvantages such as increased volume, low power device reuse rate, complex module control and slow module output response. Utility Model Content

[0005] (1) Technical problems solved

[0006] To solve the above technical problems, the utility model provides a novel bidirectional AC / DC integrated switching power supply structure, which realizes three-phase input, obtains high-voltage DC power through the ACDC converter, and the subsequent stage can realize two different outputs of DC / AC converter and DCDC converter through the full-bridge circuit, and the AC / DC output switching can be realized by switching the output relay.

[0007] (2) Technical solution

[0008] Based on this, the utility model provides the following technical solutions: a novel bidirectional AC / DC integrated switching power supply structure, the front stage of the power supply structure includes six MOS tubes, namely: MOS tube Q1, MOS tube Q2, MOS tube Q3, MOS tube Q4, MOS tube Q5, MOS tube Q6, and the six MOS tubes form a three-phase full-bridge structure;

[0009] The collector of the MOS transistor Q1 and the emitter of the MOS transistor Q2 are connected to the U bridge arm of the three-phase alternating current, the emitter of the MOS transistor Q3 and the collector of the MOS transistor Q4 are connected to the V bridge arm of the three-phase alternating current, and the collector of the MOS transistor Q5 and the emitter of the MOS transistor Q6 are connected to the W bridge arm of the three-phase alternating current;

[0010] The emitter of the MOS transistor Q5 and the collector of the MOS transistor Q6 are connected to pin 1 and pin 2 of the bus capacitor C1 respectively.

[0011] Preferably, pin 1 of the bus capacitor C1 is connected to the collector of IGBT tube Q7 and the collector of IGBT tube Q9, and pin 2 of the bus capacitor C1 is connected to the emitter of IGBT tube Q8 and the emitter of IGBT tube Q10.

[0012] Preferably, the emitter of the IGBT tube Q7 and the collector of the IGBT tube Q8 are connected to the left end of the inductor L1, and the emitter of the IGBT tube Q9 is connected to the IGBT tube Q10, and the collector is connected to the left end of the inductor L2.

[0013] Preferably, the right end of the inductor L1 is connected to pin 5 of the relay RLY1, and the right end of the inductor L2 is connected to pin 5 of the relay RLY2.

[0014] Preferably, pin 3 of the relay RLY1 and pin 3 of the relay RLY2 are connected to pin 2 and pin 1 of the inverter output capacitor C2 respectively, and pin 4 of the relay RLY2 is connected to the left end of the inductor L3.

[0015] Preferably, the inductor L3, the capacitor C3, and the capacitor C4 form a π-type filter network to reduce DC output ripple.

[0016] Preferably, pin 3 of the relay RLY1 and pin 2 of the inverter output capacitor C2 are connected to the AC power AC_L, and pin 3 of the relay RLY2 and pin 1 of the inverter output capacitor C2 are connected to the AC power AC_N.

[0017] Preferably, the right end of the inductor L3 and the pin 1 output of the capacitor C4 are connected to a DC power supply DC+, and the pin 2 of the capacitor C4 and the pin 2 output of the capacitor C3 are connected to a DC power supply DC-.

[0018] Preferably, the relay RLY1 is an output relay, and the relay RLY2 is an input relay.

[0019] (3) Beneficial effects

[0020] Compared with the prior art, the present invention provides a novel bidirectional AC / DC integrated switching power supply structure, which has the following beneficial effects:

[0021] The utility model breaks the conventional design idea and adopts a novel circuit form. In the power supply system, the front-stage topology adopts the conventional three-phase full-bridge topology, and reuses the output full-bridge circuit. It is used as a full-bridge inverter and BUCK topology at the same time. The output inductor is also reused, and one is connected to the midpoint of each of the two bridge arms. The output part uses relays for output control. The advantage of this is that the AC output and DC output are integrated into one module. At the same time, the power tube and the output inductor can be reused. Only two more relays are needed. This not only reduces the size of the module, but also increases the reuse rate of power devices and reduces costs. At the same time, it is relatively simple to control, and the output response speed is also improved. At the same time, this module can also be reversed. When the DC end is used as input, a DCDC converter (BOOST boost circuit) can be used to obtain the bus voltage and then invert it through the three-phase full-bridge to obtain a three-phase AC output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the overall structural diagram of the utility model;

[0023] Figure 2 This is the overall structure circuit connection diagram of the utility model.

[0024] In the figure: MOS tube-Q1, MOS tube-Q2, MOS tube-Q3, MOS tube-Q4, MOS tube-Q5, MOS tube-Q6, bus capacitor-C1, IGBT tube-Q7, IGBT tube-Q8, IGBT tube-Q9, IGBT tube-Q10, inductor-L1, inductor-L2, inductor-L3, relay-RLY1, relay-RLY2, inverter output capacitor-C2, capacitor-C3, capacitor-C4. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-Figure 2A novel bidirectional AC / DC integrated switching power supply structure includes six MOS transistors in the front stage, namely: MOS transistor Q1, MOS transistor Q2, MOS transistor Q3, MOS transistor Q4, MOS transistor Q5, and MOS transistor Q6. The six MOS transistors form a three-phase full-bridge structure. The collector of MOS transistor Q1 and the emitter of MOS transistor Q2 are connected to the U bridge arm of the three-phase AC power supply. The emitter of MOS transistor Q3 and the collector of MOS transistor Q4 are connected to the V bridge arm of the three-phase AC power supply. The collector of MOS transistor Q5 and the emitter of MOS transistor Q6 are connected to the W bridge arm of the three-phase AC power supply. The emitter of MOS transistor Q5 and the collector of MOS transistor Q6 are connected to pins 1 and 2 of bus capacitor C1, respectively. Pin 1 of bus capacitor C1 is connected to the collectors of IGBT transistors Q7 and Q9. Pin 2 of bus capacitor C1 is connected to the emitters of IGBT transistors Q8 and Q10.

[0027] In some embodiments, the emitter of IGBT Q7 and the collector of IGBT Q8 are connected to the left end of inductor L1, the emitter of IGBT Q9 is connected to IGBT Q10, and the collector is connected to the left end of inductor L2. The right end of inductor L1 is connected to pin 5 of relay RLY1, the right end of inductor L2 is connected to pin 5 of relay RLY2, pin 3 of relay RLY1 and pin 3 of relay RLY2 are connected to pin 2 and pin 1 of inverter output capacitor C2 respectively, and pin 4 of relay RLY2 is connected to the left end of inductor L3. Connection, inductor L3, capacitor C3, and capacitor C4 form a π-type filter network to reduce DC output ripple, pin 3 of relay RLY1 and pin 2 of inverter output capacitor C2 are connected to AC power AC_L, pin 3 of relay RLY2 and pin 1 of inverter output capacitor C2 are connected to AC power AC_N, the right end of inductor L3 and pin 1 of capacitor C4 are connected to DC power supply DC+, pin 2 of capacitor C4 and pin 2 of capacitor C3 are connected to DC power supply DC-, relay RLY1 is an output relay, and relay RLY2 is an input relay.

[0028] In this application, as attached Figure 2 As shown, viewing from left to right is considered forward operation, and from right to left is reverse operation. The reverse operation mode is DCDC-DCAC. The front stage consists of a three-phase full-bridge circuit consisting of six MOS transistors. C1 is the bus capacitor, and the four power transistors, IGBTs Q7, Q8, Q9, and Q10, are IGBTs, forming the back stage topology. Inductors L1 and L2 serve as the AC-side inverter inductor, the DC-side buck inductor, and the boost inductor.

[0029] During forward output, the six MOS transistors (MOS transistors Q1-Q6) conduct in pairs, performing three-phase full-bridge rectification, increasing the bus voltage. During AC output, the four IGBT transistors (IGBT transistors) Q7-Q9 perform full-bridge inverter control. IGBT transistors Q7 and Q10 synchronize, while IGBT transistors Q7 and Q8 generate complementary waveforms. IGBT transistors Q9 and Q8 synchronize, while IGBT transistors Q9 and Q10 generate complementary waveforms. After LC filtering through the output inductor and capacitor, the AC voltage is obtained.

[0030] During DC output, IGBTs Q7 and Q8 form a buck circuit. When IGBT Q7 turns on, inductor L1 begins storing energy and current increases, charging inverter output capacitor C2 and providing energy to the load. When IGBT Q7 turns off, the inductor current cannot change suddenly, so the body diode of IGBT Q8 acts as a freewheeling circuit. IGBTs Q9 and Q10 form another buck circuit, operating in the same way. The two buck circuits generate synchronously, reducing current stress on each transistor. Inductor L2 also acts as the inductor for the other circuit.

[0031] When outputting in reverse, the four IGBTs (IGBTs) Q7 through Q10 form two boost circuits, with inductors L1 and L2 acting as energy storage inductors for the two circuits, respectively. With IGBTs Q7 and Q8 as one circuit, when IGBT Q8 is on, inductor L1 stores energy and simultaneously charges bus capacitor C1. When IGBT Q8 is off, the inductor current remains constant and freewheels through the body diode of IGBT Q7. The other circuit operates in a similar manner, with both circuits generating synchronously in boost mode. When the bus voltage reaches a certain level, the six MOS transistors (MOS transistors) Q1 through Q6 perform a three-phase full-bridge inverter to generate three-phase AC power.

[0032] The two working modes are combined together to effectively utilize the power tube and inductor, which not only reduces the volume but also has obvious advantages in reducing costs.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel bidirectional AC / DC integrated switching power supply structure, characterized by: The front stage of the power supply structure includes six MOS tubes, namely: MOS tube (Q1), MOS tube (Q2), MOS tube (Q3), MOS tube (Q4), MOS tube (Q5), and MOS tube (Q6), and the six MOS tubes form a three-phase full-bridge structure; The collector of the MOS tube (Q1) and the emitter of the MOS tube (Q2) are connected to the U bridge arm of the three-phase alternating current, the emitter of the MOS tube (Q3) and the collector of the MOS tube (Q4) are connected to the V bridge arm of the three-phase alternating current, and the collector of the MOS tube (Q5) and the emitter of the MOS tube (Q6) are connected to the W bridge arm of the three-phase alternating current; The emitter of the MOS tube (Q5) and the collector of the MOS tube (Q6) are respectively connected to pin No. 1 and pin No. 2 of the bus capacitor (C1).

2. The novel bidirectional AC / DC integrated switching power supply structure according to claim 1, characterized in that: Pin 1 of the bus capacitor (C1) is connected to the collector of the IGBT tube (Q7) and the collector of the IGBT tube (Q9), and pin 2 of the bus capacitor (C1) is connected to the emitter of the IGBT tube (Q8) and the emitter of the IGBT tube (Q10).

3. The novel bidirectional AC / DC integrated switching power supply structure according to claim 2, characterized in that: The emitter of the IGBT tube (Q7), the collector of the IGBT tube (Q8) and the left end of the inductor (L1) are connected; the emitter of the IGBT tube (Q9) and the collector of the IGBT tube (Q10) are connected to the left end of the inductor (L2).

4. The novel bidirectional AC / DC integrated switching power supply structure according to claim 3, characterized in that: The right end of the inductor (L1) is connected to pin No. 5 of the relay (RLY1), and the right end of the inductor (L2) is connected to pin No. 5 of the relay (RLY2).

5. The novel bidirectional AC / DC integrated switching power supply structure according to claim 4, characterized in that: Pin 3 of the relay (RLY1) and pin 3 of the relay (RLY2) are respectively connected to pin 2 and pin 1 of the inverter output capacitor (C2), and pin 4 of the relay (RLY2) is connected to the left end of the inductor (L3).

6. The novel bidirectional AC / DC integrated switching power supply structure according to claim 5, characterized in that: The inductor (L3), the capacitor (C3) and the capacitor (C4) form a π-type filter network to reduce DC output ripple.

7. The novel bidirectional AC / DC integrated switching power supply structure according to claim 4, characterized in that: Pin 3 of the relay (RLY1) and pin 2 of the inverter output capacitor (C2) are connected to an alternating current (AC_L), and pin 3 of the relay (RLY2) and pin 1 of the inverter output capacitor (C2) are connected to an alternating current (AC_N).

8. The novel bidirectional AC / DC integrated switching power supply structure according to claim 6, characterized in that: The right end of the inductor (L3) and the pin 1 output of the capacitor (C4) are connected to a DC power supply (DC+), and the pin 2 of the capacitor (C4) and the pin 2 output of the capacitor (C3) are connected to a DC power supply (DC-).

9. The novel bidirectional AC / DC integrated switching power supply structure according to claim 7, characterized in that: The relay (RLY1) is an output relay, and the relay (RLY2) is an input relay.

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