Power conversion system and auxiliary power supply circuit
By designing an auxiliary power supply circuit, the conversion, rectification and power supply circuits are used to draw power from multiple power supplies and convert each other into auxiliary power supply voltages, the circuit complexity and cost problems caused by multiple auxiliary power supplies are solved, and the system volume and cost reduction is achieved.
Patent Information
- Application Number
- CN202421383603.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-04-04
- Estimated Expiration
- 2034-06-17
AI Technical Summary
In existing power conversion systems, multiple auxiliary power supplies lead to complex circuit layout, increasing the system size and cost.
An auxiliary power supply circuit is designed, including a conversion circuit, a rectifier circuit and a power withdrawal circuit, through which power is drawn from the first ends of the mains, DC bus and the buck-up circuit, and converted into an auxiliary power supply voltage for supplying the auxiliary power supply terminals of the buck-up circuit and the power conversion circuit.
It reduces the complexity of the auxiliary power supply circuit, reduces the volume and cost of the power conversion system, and ensures the normal start-up of the system.
Smart Images
Figure CN222721353U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of power conversion circuits, and in particular to a power conversion system and an auxiliary power supply circuit thereof. Background Art
[0002] In an existing power conversion system, a plurality of auxiliary power supplies are generally provided to provide auxiliary power supply to a buck-boost circuit and a power conversion circuit in the power conversion system.
[0003] After the power conversion system starts and works normally, in order to reduce power consumption, one of the multiple auxiliary power supplies will be controlled to provide auxiliary power, and the other auxiliary power supplies are idle. Multiple auxiliary power supplies will make the circuit layout of the power conversion system more complicated, resulting in a larger size and higher cost of the power conversion system. Utility Model Content
[0004] In view of this, the present application provides a power conversion system and an auxiliary power supply circuit thereof, which are used to reduce the complexity of the auxiliary power supply circuit, thereby reducing the volume and cost of the power conversion system. The technical solution of the present application is as follows:
[0005] The first aspect of the present application provides an auxiliary power supply circuit of a power conversion system, the power conversion system also includes a power conversion circuit and a buck-boost circuit, the auxiliary power supply circuit includes a conversion circuit, a rectifier circuit and a power extraction circuit; the input end of the power extraction circuit is connected to the DC bus of the power conversion circuit and the first end of the buck-boost circuit, and the output end of the power extraction circuit is connected to the input end of the conversion circuit; the input end of the rectifier circuit is connected to the AC power end of the power conversion system, the output end of the rectifier circuit is connected to the input end of the conversion circuit, and the AC power end is used to connect to the AC; the output end of the conversion circuit is connected to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit, and the conversion circuit is used to receive the power supply voltage of the power extraction circuit and / or the rectifier circuit, convert the power supply voltage into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit.
[0006] In one embodiment of the present application, the power conversion system includes n buck-boost circuits, and the power supply circuit includes n first anti-reverse units, each of the first anti-reverse units is connected to the first end of one of the buck-boost circuits and the input end of the power supply circuit, and n is a positive integer greater than or equal to 2; the first anti-reverse unit is used to obtain electrical energy from the corresponding buck-boost circuit and transmit it to the conversion circuit, and prevent the current at the output end of the rectifier circuit from flowing to the buck-boost circuit.
[0007] In one embodiment of the present application, the first anti-reverse unit includes a first diode, the anode of the first diode is connected to the first end of the buck-boost circuit, and the cathode of the first diode is connected to the input end of the conversion circuit.
[0008] In one embodiment of the present application, the power supply circuit also includes a second anti-reverse unit, which is connected to the DC bus of the power conversion circuit and the input end of the power supply circuit; the second anti-reverse unit is used to obtain electrical energy from the power conversion circuit and transmit it to the conversion circuit, and prevent the current at the output end of the rectifier circuit from flowing to the power conversion circuit.
[0009] In one embodiment of the present application, the second anti-reverse unit includes a second diode, the positive electrode of the second diode is connected to the DC bus of the power conversion circuit, and the negative electrode of the second diode is connected to the input end of the conversion circuit. In one embodiment of the present application, the power supply circuit also includes a current limiting unit, and the first anti-reverse unit and the second anti-reverse unit are connected to the input end of the power supply circuit through the current limiting unit; the current limiting unit is used to limit the current flowing to the input end of the power supply circuit to not exceed a preset current value.
[0010] In an embodiment of the present application, the current limiting unit includes a resistor, and the first anti-reverse unit and the second anti-reverse unit are connected to the input end of the power taking circuit through the resistor.
[0011] The second aspect of the present application provides a power conversion system, including an auxiliary power supply circuit, a power conversion circuit and n buck-boost circuits, where n is a positive integer greater than or equal to 2; the first end of each of the buck-boost circuits is used to connect to a corresponding DC power supply, the first end of the power conversion circuit is connected to the second end of each of the buck-boost circuits, the second end of the power conversion circuit is connected to a mains power end, and the mains power end is used to connect to the mains; the input end of the auxiliary power supply circuit is connected to the mains power end, the DC bus of the power conversion circuit, the first end of each of the buck-boost circuits, the auxiliary power supply end of the power conversion circuit and the auxiliary power supply end of each of the buck-boost circuits; the auxiliary power supply circuit is used to draw power from the mains power end, the DC bus of the power conversion circuit and / or the first end of the buck-boost circuit, convert it into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of each of the buck-boost circuits and the auxiliary power supply end of the power conversion circuit.
[0012] In one embodiment of the present application, the auxiliary power supply circuit includes a conversion circuit, a rectifier circuit and a power extraction circuit; the input end of the power extraction circuit is connected to the DC bus of the power conversion circuit and the first end of each buck-boost circuit, the output end of the power extraction circuit is connected to the input end of the conversion circuit, the input end of the rectifier circuit is connected to the AC power end, and the output end of the rectifier circuit is connected to the input end of the conversion circuit; the output end of the conversion circuit is connected to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit, and the conversion circuit is used to receive the power supply voltage of the power extraction circuit and / or the rectifier circuit, convert the power supply voltage into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit.
[0013] In one embodiment of the present application, the DC power supply includes a photovoltaic panel and an energy storage battery.
[0014] The conversion circuit of the present application is connected to the first end of the buck-boost circuit, the DC bus of the power conversion circuit, and the mains end through a power-taking circuit. When the first end of the buck-boost circuit is connected to a DC power supply, or when there is electric energy in the DC bus of the power conversion circuit, or when the mains end is connected to the mains, the conversion circuit can receive the supply voltage and convert the supply voltage into an auxiliary supply voltage to provide auxiliary power to the buck-boost circuit and the power conversion circuit, thereby ensuring that the power conversion system can start and work normally, and at the same time, it can reduce the complexity of the auxiliary power supply circuit, thereby reducing the volume and cost of the power conversion system. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic block diagram of an auxiliary power supply circuit provided in an embodiment of the present application.
[0016] Figure 2 It is a schematic block diagram of another auxiliary power supply circuit provided in an embodiment of the present application.
[0017] Figure 3 It is a schematic block diagram of a third auxiliary power supply circuit provided in an embodiment of the present application.
[0018] Figure 4 It is a schematic block diagram of the fourth auxiliary power supply circuit provided in an embodiment of the present application.
[0019] Figure 5 It is a schematic block diagram of a power conversion system provided in an embodiment of the present application. DETAILED DESCRIPTION
[0020] It should be noted that in the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The terms "first", "second", "third", "fourth", etc. (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.
[0021] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.
[0022] In an existing power conversion system, a plurality of auxiliary power supplies are generally provided to provide auxiliary power supply to a buck-boost circuit and a power conversion circuit in the power conversion system.
[0023] After the power conversion system starts and works normally, in order to reduce power consumption, one of the multiple auxiliary power supplies will be controlled to provide auxiliary power, and the other auxiliary power supplies are idle. Multiple auxiliary power supplies will make the circuit layout of the power conversion system more complicated, resulting in a larger size and higher cost of the power conversion system.
[0024] The present application provides a power conversion system and an auxiliary power supply circuit thereof, which are used to reduce the complexity of the auxiliary power supply circuit, thereby reducing the volume and cost of the power conversion system.
[0025] Please refer to Figure 1 , Figure 1 The auxiliary power supply circuit 100 is a schematic block diagram of an auxiliary power supply circuit provided in an embodiment of the present application. The auxiliary power supply circuit 100 includes a conversion circuit 110 , a rectifier circuit 120 and a power supply circuit 130 .
[0026] In the embodiment of the present application, the input end of the power taking circuit 130 is connected to the DC bus of the power conversion circuit 101 of the power conversion system 10 and the first end of the buck-boost circuit 102, the output end of the power taking circuit 130 is connected to the input end of the conversion circuit 110, the input end of the rectifier circuit 120 is connected to the mains terminal 103 of the power conversion system 10, and the output end of the rectifier circuit 120 is connected to the input end of the conversion circuit 110. The mains terminal 103 is used to connect to the mains.
[0027] Among them, the output end of the conversion circuit 110 is connected to the auxiliary power supply end of the buck-boost circuit 102 and the auxiliary power supply end of the power conversion circuit 101, and the conversion circuit 110 is used to receive the power supply voltage of the power taking circuit 130 and / or the rectifier circuit 120, convert the power supply voltage into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of the buck-boost circuit 102 and the auxiliary power supply end of the power conversion circuit 101.
[0028] In some embodiments, the first end of the buck-boost circuit 102 is used to connect to a DC power supply, and the buck-boost circuit 102 includes a buck circuit, a boost circuit, or a buck-boost circuit that can adjust the voltage and stabilize the output voltage. The DC power supply includes a storage battery, or unstable clean energy, such as a photovoltaic power supply and a wind power supply, which are not limited here. The power conversion circuit 101 may include a DCDC circuit and a DCAC circuit, and the DCDC circuit and the DCAC circuit are connected through the DC bus and the bus capacitor.
[0029] It can be understood that the above-mentioned conversion circuit 110 is connected to the first end of the buck-boost circuit 102, the DC bus of the power conversion circuit 101, and is connected to the AC power end 103 through the rectifier circuit 120. When the first end of the buck-boost circuit is connected to a DC power supply, or when there is electric energy in the DC bus of the power conversion circuit 101, or when the AC power end 103 is connected to the AC, the conversion circuit 110 can receive the power supply voltage and convert the power supply voltage into an auxiliary power supply voltage to provide auxiliary power supply to the buck-boost circuit 102 and the power conversion circuit 101, thereby ensuring that the power conversion system 10 can start and work normally, and can also reduce the complexity of the auxiliary power supply circuit 100, thereby reducing the volume and cost of the power conversion system 10.
[0030] In some embodiments, Figure 2 As shown, the power conversion system 10 includes n buck-boost circuits 102, and the power supply circuit 130 includes n first anti-reverse units 131, each first anti-reverse unit 131 is connected to the first end of one of the buck-boost circuits 102 and the input end of the power supply circuit 130, and n is a positive integer greater than or equal to 2.
[0031] The first anti-reverse unit 131 is used to obtain electric energy from the corresponding buck-boost circuit 102 and transmit it to the conversion circuit 110, and prevent the current at the output end of the rectifier circuit 120 from flowing to the buck-boost circuit 102. That is, the first end of each buck-boost circuit 102 can be used to connect to a DC power supply. When the first end of one of the buck-boost circuits 102 has DC power input, the power circuit 130 can obtain power from the first end of the corresponding buck-boost circuit 102 through the first anti-reverse unit 131.
[0032] In the embodiment of the present application, the power taking circuit 130 further includes a second anti-reverse unit 132, and the second anti-reverse unit 132 is connected to the DC bus of the power conversion circuit 101 and the input end of the power taking circuit 130. The second anti-reverse unit 132 is used to obtain electric energy from the power conversion circuit 101 and transmit it to the conversion circuit 110, and prevent the current at the output end of the rectifier circuit 120 from flowing to the power conversion circuit 101.
[0033] In some embodiments, Figure 3 As shown, the first anti-reverse unit 131 includes a first diode D1, the positive electrode of the first diode D1 is connected to the first end of the buck-boost circuit 102, and the negative electrode of the first diode D1 is connected to the input end of the conversion circuit 110. The second anti-reverse unit 132 includes a second diode D2, the positive electrode of the second diode D2 is connected to the DC bus of the power conversion circuit 101, and the negative electrode of the second diode D2 is connected to the input end of the conversion circuit 110.
[0034] In some embodiments, Figure 4 As shown, the power supply circuit 130 also includes a current limiting unit 133. The first anti-reverse unit 131 and the second anti-reverse unit 132 are connected to the input end of the power supply circuit through the current limiting unit 133. The current limiting unit 133 is used to limit the current flowing to the input end of the power supply circuit to not exceed a preset current value.
[0035] The current limiting unit 133 includes a resistor R1 , and the first anti-reverse unit 131 and the second anti-reverse unit 132 are connected to the input end of the power taking circuit through the resistor R1 .
[0036] Please refer to Figure 5 , Figure 5 A schematic block diagram of a power conversion system provided in an embodiment of the present application, wherein the power conversion system 500 includes an auxiliary power supply circuit 510, a power conversion circuit 520, and n buck-boost circuits 530, where n is a positive integer greater than or equal to 2.
[0037] Among them, the first end of each buck-boost circuit 530 is respectively used to connect to the corresponding DC power supply 501, the first end of the power conversion circuit 520 is connected to the second end of each buck-boost circuit 530, and the second end of the power conversion circuit 520 is connected to the mains terminal 502. The input end of the auxiliary power supply circuit 510 is connected to the mains terminal 502, the DC bus of the power conversion circuit 520, the first end of each buck-boost circuit 530, the auxiliary power supply end of the power conversion circuit 520, and the auxiliary power supply end of each buck-boost circuit 530. The auxiliary power supply circuit 510 is used to draw power from the mains terminal 502, the DC bus of the power conversion circuit 520 and / or the first end of the buck-boost circuit 530, convert it into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of each buck-boost circuit 530 and the auxiliary power supply end of the power conversion circuit 520. The above-mentioned DC power supply 501 includes a photovoltaic panel and an energy storage battery.
[0038] In the embodiment of the present application, the auxiliary power supply circuit 510 includes a conversion circuit 511, a rectifier circuit 512 and a power supply circuit 513. The input end of the power supply circuit 513 is connected to the DC bus of the power conversion circuit 520 and the first end of each buck-boost circuit 530, the output end of the power supply circuit 513 is connected to the input end of the conversion circuit 511, the input end of the rectifier circuit 512 is connected to the mains terminal 502, and the output end of the rectifier circuit 512 is connected to the input end of the conversion circuit 511. The output end of the conversion circuit 511 is connected to the auxiliary power supply end of the buck-boost circuit 530 and the auxiliary power supply end of the power conversion circuit 520. The conversion circuit 511 is used to receive the power supply voltage of the power supply circuit 513 and / or the rectifier circuit 512, convert the power supply voltage into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of the buck-boost circuit 530 and the auxiliary power supply end of the power conversion circuit 520.
[0039] The above embodiments are merely preferred embodiments of the present application and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the protection scope of the claims of the present application.
Claims
1. An auxiliary power supply circuit of a power conversion system, the power conversion system further comprising a power conversion circuit and a buck-boost circuit, characterized in that: The auxiliary power supply circuit includes a conversion circuit, a rectification circuit and a power supply circuit; The input end of the power taking circuit is connected to the DC bus of the power conversion circuit and the first end of the buck-boost circuit, and the output end of the power taking circuit is connected to the input end of the conversion circuit; The input end of the rectifier circuit is connected to the mains terminal of the power conversion system, the output end of the rectifier circuit is connected to the input end of the conversion circuit, and the mains terminal is used to connect to the mains; The output end of the conversion circuit is connected to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit. The conversion circuit is used to receive the power supply voltage of the power extraction circuit and / or the rectifier circuit, convert the power supply voltage into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit.
2. The auxiliary power supply circuit according to claim 1, characterized in that: The power conversion system includes n buck-boost circuits, the power taking circuit includes n first anti-reverse units, each of the first anti-reverse units is connected to the first end of one of the buck-boost circuits and the input end of the power taking circuit, and n is a positive integer greater than or equal to 2; The first anti-reverse unit is used to obtain electric energy from the corresponding buck-boost circuit and transmit it to the conversion circuit, and to prevent the current at the output end of the rectifier circuit from flowing to the buck-boost circuit.
3. The auxiliary power supply circuit according to claim 2, characterized in that: The first anti-reverse unit includes a first diode, an anode of the first diode is connected to a first end of the buck-boost circuit, and a cathode of the first diode is connected to an input end of the conversion circuit.
4. The auxiliary power supply circuit according to claim 2, characterized in that: The power taking circuit further includes a second anti-reverse unit, wherein the second anti-reverse unit is connected to the DC bus of the power conversion circuit and the input end of the power taking circuit; The second anti-reverse unit is used for obtaining electric energy from the power conversion circuit and transmitting it to the conversion circuit, and preventing the current at the output end of the rectifier circuit from flowing to the power conversion circuit.
5. The auxiliary power supply circuit according to claim 4, characterized in that: The second anti-reverse unit includes a second diode, the anode of the second diode is connected to the DC bus of the power conversion circuit, and the cathode of the second diode is connected to the input end of the conversion circuit.
6. The auxiliary power supply circuit according to claim 4, characterized in that: The power taking circuit further includes a current limiting unit, and the first anti-reverse unit and the second anti-reverse unit are connected to the input end of the power taking circuit through the current limiting unit; The current limiting unit is used to limit the current flowing to the input end of the power taking circuit to not exceed a preset current value.
7. The auxiliary power supply circuit according to claim 6, characterized in that: The current limiting unit includes a resistor, and the first anti-reverse unit and the second anti-reverse unit are connected to the input end of the power taking circuit through the resistor.
8. A power conversion system, characterized in that: It includes an auxiliary power supply circuit, a power conversion circuit and n step-up and step-down circuits, where n is a positive integer greater than or equal to 2; The first end of each of the buck-boost circuits is respectively used to be connected to a corresponding DC power supply, the first end of the power conversion circuit is connected to the second end of each of the buck-boost circuits, the second end of the power conversion circuit is connected to the mains terminal, and the mains terminal is used to be connected to the mains; The input end of the auxiliary power supply circuit is connected to the mains end, the DC bus of the power conversion circuit, the first end of each of the buck-boost circuits, the auxiliary power supply end of the power conversion circuit and the auxiliary power supply end of each of the buck-boost circuits; The auxiliary power supply circuit is used to draw power from the AC power end, the DC bus of the power conversion circuit and / or the first end of the buck-boost circuit, convert it into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of each buck-boost circuit and the auxiliary power supply end of the power conversion circuit.
9. The power conversion system according to claim 8, characterized in that: The auxiliary power supply circuit includes a conversion circuit, a rectification circuit and a power supply circuit; The input end of the power taking circuit is connected to the DC bus of the power conversion circuit and the first end of each of the buck-boost circuits, the output end of the power taking circuit is connected to the input end of the conversion circuit, the input end of the rectifier circuit is connected to the mains terminal, and the output end of the rectifier circuit is connected to the input end of the conversion circuit; The output end of the conversion circuit is connected to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit. The conversion circuit is used to receive the power supply voltage of the power extraction circuit and / or the rectifier circuit, convert the power supply voltage into an auxiliary power supply voltage and transmit it to the auxiliary power supply end of the buck-boost circuit and the auxiliary power supply end of the power conversion circuit.
10. The power conversion system according to claim 8 or 9, characterized in that: The DC power supply includes a photovoltaic panel and an energy storage battery.