A wind power converter and control method

Abstract

The application relates to a wind power converter and a control method, and belongs to the technical field of power electronics, which comprises a grid-side alternating current circuit, a machine-side alternating current circuit, a grid-side full-controlled device circuit, a machine-side full-controlled device circuit and a direct-current side circuit; the first end of the grid-side alternating current circuit is connected to three-phase lines of a power grid through a circuit breaker, the second end of the grid-side alternating current circuit is connected to the first end of the direct-current side circuit through the grid-side full-controlled device circuit, and the second end of the direct-current side circuit is connected to the machine-side alternating current circuit through the machine-side full-controlled device circuit; the application can disconnect the full-controlled switch tube Q1 and the full-controlled switch tube Q2 when a short-circuit fault occurs at the direct-current side, block the connection of the direct-current side circuit with the grid-side alternating current circuit, the machine-side alternating current circuit, the grid-side full-controlled device circuit and the machine-side full-controlled device circuit, protect power electronic elements, discharge energy through a chopper circuit, and ensure the safety of the whole wind power converter.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, specifically relating to a wind power converter and its control method. Background Technology

[0002] Traditional wind power converters are unable to cope with DC-side short-circuit faults. When a fault occurs, in order to protect the power electronic devices, it is usually necessary to shut down the pulses of fully controllable devices. At this time, the circuit operates in uncontrolled rectification mode. Due to the slow speed of circuit breakers or traditional switch protection, it is often unable to prevent the further spread of the fault. Consequently, the IGBT module explodes due to the DC-side short circuit, posing a serious safety hazard. This is the shortcoming of the existing technology.

[0003] In view of this, it is very necessary to provide a wind power converter and control method to solve the above-mentioned defects in the prior art. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing wind power converters in handling DC-side short-circuit faults by providing a wind power converter and control method to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a wind power converter, comprising: a grid-side AC circuit, a machine-side AC circuit, a grid-side fully controlled device circuit, a machine-side fully controlled device circuit, and a DC-side circuit;

[0007] The first end of the grid-side AC circuit is connected to the three-phase line of the power grid through a circuit breaker. The second end of the grid-side AC circuit is connected to the first end of the DC-side circuit through the grid-side fully controlled device circuit. The second end of the DC-side circuit is connected to the machine-side AC circuit through the machine-side fully controlled device circuit.

[0008] The DC-side circuit includes fully controlled transistors Q1 and Q2, resistors R1 and R2, a chopper circuit, and a voltmeter. The chopper circuit includes resistors R3 and R4, capacitors C1 and C2, and fully controlled transistors Q3 and Q4. The collector of fully controlled transistor Q1 is connected to the grid-side fully controlled device circuit. The emitter of fully controlled transistor Q1 is connected to the first terminal of the voltmeter, and the second terminal of the voltmeter is connected to the grid-side fully controlled device circuit. The emitter of fully controlled transistor Q1 is connected to the first terminal of resistor R1, and the second terminal of resistor R1 is connected to the grid-side fully controlled device circuit, the machine-side fully controlled device circuit, and resistor R2. The first terminal of resistor R2 is connected to the second terminal of the voltmeter; capacitor C1 is connected in parallel across resistor R1, the first terminal of resistor R1 is connected to the collector of fully controlled switching transistor Q3 through resistor R3, and the emitter of fully controlled switching transistor Q3 is connected to the second terminal of resistor R1; capacitor C2 is connected in parallel across resistor R2, the first terminal of resistor R2 is connected to the collector of fully controlled switching transistor Q4 through resistor R4, and the emitter of fully controlled switching transistor Q4 is connected to the second terminal of resistor R2; the emitter of fully controlled switching transistor Q2 is connected to the emitter of fully controlled switching transistor Q1, and the collector of fully controlled switching transistor Q2 is connected to the machine-side fully controlled device circuit.

[0009] In one embodiment, the grid-side fully controlled device circuit includes fully controlled switching transistors Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15, and Q16, as well as diodes D1, D2, D3, D4, D5, and D6.

[0010] The collectors of fully controlled transistors Q5, Q6, and Q7 are all connected to the collector of fully controlled transistor Q1. The emitter of fully controlled transistor Q5 is connected to the cathode of diode D1 and the collector of fully controlled transistor Q8. The anode of diode D1 is connected to the second terminal of resistor R1. The emitter of fully controlled transistor Q8 is connected to the AC grid circuit and the collector of fully controlled transistor Q11. The emitter of fully controlled transistor Q6 is connected to diode D2. The cathode of diode D2 is connected to the collector of fully controlled switch Q9, the anode of diode D2 is connected to the second terminal of resistor R1, the emitter of fully controlled switch Q9 is connected to the grid-side AC circuit and the collector of fully controlled switch Q12; the emitter of fully controlled switch Q7 is connected to the cathode of diode D3 and the collector of fully controlled switch Q10, the anode of diode D3 is connected to the second terminal of resistor R1, and the emitter of fully controlled switch Q10 is connected to the grid-side AC circuit and the collector of fully controlled switch Q13.

[0011] The emitter of the fully controlled transistor Q11 is connected to the collector of the fully controlled transistor Q14 and the anode of diode D4. The cathode of diode D4 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q14 is connected to the second terminal of the voltmeter. The emitter of the fully controlled transistor Q12 is connected to the collector of the fully controlled transistor Q15 and the anode of diode D5. The cathode of diode D5 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q15 is connected to the second terminal of the voltmeter. The emitter of the fully controlled transistor Q13 is connected to the collector of the fully controlled transistor Q16 and the anode of diode D6. The cathode of diode D6 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q16 is connected to the second terminal of the voltmeter.

[0012] In one embodiment, the machine-side fully controlled device circuit includes fully controlled switching transistors Q17, Q18, Q19, Q20, Q21, Q22, Q23, Q24, Q25, Q26, Q27, Q28, diodes D7, D8, D9, D10, D11, and D12;

[0013] The collectors of fully controlled transistors Q17, Q18, and Q19 are all connected to the collector of fully controlled transistor Q2. The emitter of fully controlled transistor Q17 is connected to the collector of fully controlled transistor Q20. The emitter of fully controlled transistor Q20 is connected to the machine-side AC circuit, the collector of fully controlled transistor Q23, and the cathode of diode D7. The anode of diode D7 is connected to the second terminal of resistor R1. The emitter of fully controlled transistor Q18 is connected to the fully controlled transistor... The collector of the fully controlled switch Q21 and the emitter of the fully controlled switch Q21 are connected to the machine-side AC circuit. The collector of the fully controlled switch Q24 and the cathode of the diode D8 are connected to the cathode of the diode D8. The anode of the diode D8 is connected to the second terminal of the resistor R1. The emitter of the fully controlled switch Q19 is connected to the collector of the fully controlled switch Q22. The emitter of the fully controlled switch Q22 is connected to the machine-side AC circuit. The collector of the fully controlled switch Q25 and the cathode of the diode D9 are connected to the cathode of the diode D9. The anode of the diode D9 is connected to the second terminal of the resistor R1.

[0014] The collector of the fully controlled switching transistor Q23 is also connected to the anode of diode D10, and the cathode of diode D10 is connected to the second terminal of resistor R1. The collector of the fully controlled switching transistor Q24 is also connected to the anode of diode D11, and the cathode of diode D11 is connected to the second terminal of resistor R1. The collector of the fully controlled switching transistor Q25 is also connected to the anode of diode D12, and the cathode of diode D12 is connected to the second terminal of resistor R1. The emitter of the fully controlled switching transistor Q23 is connected to the collector of the fully controlled switching transistor Q26. The emitter of the fully controlled switching transistor Q24 is connected to the collector of the fully controlled switching transistor Q27. The emitter of the fully controlled switching transistor Q25 is connected to the collector of the fully controlled switching transistor Q28. The emitters of the fully controlled switching transistors Q26, Q27, and Q28 are all connected to the second terminal of the voltmeter.

[0015] In one embodiment, the grid-side AC circuit includes inductors L1, L2, and L3 connected in series on the three-phase lines of the power grid, and current transformers CT1, CT2, and CT3 installed on the three-phase lines of the power grid.

[0016] In one embodiment, the machine-side AC circuit includes inductors L4, L5, and L6 connected in series on the three-phase lines of the power grid, and current transformers CT4, CT5, and CT6 installed on the three-phase lines of the power grid.

[0017] In one embodiment, the third terminal of the grid-side AC circuit is connected to the stator terminal of the doubly-fed induction generator, and a normally open contact of a contactor for controlling the start and stop of the doubly-fed induction generator is connected in series between the third terminal of the grid-side AC circuit and the stator terminal of the doubly-fed induction generator.

[0018] In one embodiment, a voltage sensor is also provided between the normally open contact of the contactor and the third terminal of the grid-side AC circuit.

[0019] Secondly, the present invention provides a control method for a wind power converter based on any one of the above claims, comprising:

[0020] Obtain the grid voltage of the three-phase lines of the power grid, the DC voltage of the DC side circuit, the AC current of the grid side AC circuit, and the AC current of the machine side AC circuit;

[0021] The obtained grid voltage of the three-phase line is compared with 0.8 times the rated voltage of the three-phase line of the grid; the obtained DC voltage of the DC side circuit is compared with 1.3 times the rated DC voltage; the obtained AC current of the grid side AC circuit is compared with 5 times the rated grid current; and the obtained AC current of the machine side AC circuit is compared with 5 times the rated machine current.

[0022] If the AC current of the grid-side AC circuit is greater than or equal to 5 times the grid-side rated current or the AC current of the generator-side AC circuit is greater than or equal to 5 times the generator-side rated current, and the grid voltage of the three-phase line of the grid is greater than or equal to 0.8 times the rated voltage of the three-phase line of the grid, and the DC voltage of the DC-side circuit is greater than or equal to 1.3 times the rated DC voltage, then a short circuit fault is determined to have occurred in the DC-side circuit.

[0023] Disconnect the fully controlled switching transistors Q1 and Q2 to block the connection between the DC side circuit and the grid side AC circuit, the machine side AC circuit, the grid side fully controlled device circuit, and the machine side fully controlled device circuit;

[0024] Trigger the chopper circuit to release energy.

[0025] In one embodiment, a voltage sensor is used to obtain the grid voltage of the three-phase lines of the power grid, a voltmeter is used to obtain the DC side voltage of the DC side circuit, current transformers CT1, CT4, CT5, and CT6 are used to obtain the AC current of the grid-side AC circuit, and current transformers CT4, CT5, and CT6 are used to obtain the AC current of the machine-side AC circuit.

[0026] The beneficial effects of this invention are that, when a short circuit fault occurs on the DC side, it can disconnect the fully controlled switching transistors Q1 and Q2, block the connection between the DC side circuit and the grid-side AC circuit, the machine-side AC circuit, the grid-side fully controlled device circuit, and the machine-side fully controlled device circuit, protect the power electronic components, and discharge energy through a chopper circuit to ensure the overall safety of the converter.

[0027] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects.

[0028] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0029] Figure 1 This is the circuit diagram of a wind power converter.

[0030] Figure 2 This is a flowchart illustrating the control method.

[0031] Figure 3 This is a graph showing the relationship between output voltage and time when there is no chopper in the DC side circuit.

[0032] Figure 4 This is a graph showing the relationship between output voltage and time when the DC-side circuit has a chopper.

[0033] 1 is the grid-side AC circuit, 2 is the generator-side AC circuit, 3 is the grid-side fully controlled device circuit, 4 is the generator-side fully controlled device circuit, 5 is the DC side circuit, QF is the normally open auxiliary contact of the circuit breaker, 6 is the voltmeter, 7 is the voltage sensor, 8 is the doubly fed induction generator, and KM is the normally open contact of the contactor. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following implementation methods.

[0035] like Figure 1 As shown, the present invention provides a wind power converter, comprising: a grid-side AC circuit, a turbine-side AC circuit, a grid-side fully controlled device circuit, a turbine-side fully controlled device circuit, and a DC-side circuit; the first terminal of the grid-side AC circuit is connected to the three-phase line of the power grid through a normally open auxiliary contact of a circuit breaker, the second terminal of the grid-side AC circuit is connected to the first terminal of the DC-side circuit through the grid-side fully controlled device circuit, and the second terminal of the DC-side circuit is connected to the turbine-side AC circuit through the turbine-side fully controlled device circuit; the turbine-side AC circuit is connected to a doubly-fed induction generator.

[0036] The DC-side circuit includes fully controlled transistors Q1 and Q2, resistors R1 and R2, a chopper circuit, and a voltmeter. The chopper circuit includes resistors R3 and R4, capacitors C1 and C2, and fully controlled transistors Q3 and Q4. The collector of fully controlled transistor Q1 is connected to the grid-side fully controlled device circuit, the emitter of fully controlled transistor Q1 is connected to the first terminal of the voltmeter, the second terminal of the voltmeter is connected to the grid-side fully controlled device circuit, the emitter of fully controlled transistor Q1 is connected to the first terminal of resistor R1, and the second terminal of resistor R1 is connected to the grid-side fully controlled device circuit, the machine-side fully controlled device circuit, and resistor R1. The first terminal of resistor R2 is connected to the second terminal of the voltmeter; capacitor C1 is connected in parallel across resistor R1, the first terminal of resistor R1 is connected to the collector of fully controlled switching transistor Q3 through resistor R3, and the emitter of fully controlled switching transistor Q3 is connected to the second terminal of resistor R1; capacitor C2 is connected in parallel across resistor R2, the first terminal of resistor R2 is connected to the collector of fully controlled switching transistor Q4 through resistor R4, and the emitter of fully controlled switching transistor Q4 is connected to the second terminal of resistor R2; the emitter of fully controlled switching transistor Q2 is connected to the emitter of fully controlled switching transistor Q1, and the collector of fully controlled switching transistor Q2 is connected to the machine-side fully controlled device circuit.

[0037] The grid-side fully controlled device circuit includes fully controlled switching transistors Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15, and Q16; diodes D1, D2, D3, D4, D5, and D6; and the collectors of fully controlled switching transistors Q5 and Q6. The collectors of both the fully controlled transistor Q7 and Q8 are connected to the collector of the fully controlled transistor Q1. The emitter of the fully controlled transistor Q5 is connected to the cathode of diode D1 and the collector of the fully controlled transistor Q8. The anode of diode D1 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q8 is connected to the AC circuit on the grid side and the collector of the fully controlled transistor Q11. The emitter of the fully controlled transistor Q6 is connected to the cathode of diode D2 and the collector of the fully controlled transistor Q9. The anode of diode D2 is connected to the second terminal of resistor R1. The emitter of transistor Q9 is connected to the grid-side AC circuit and the collector of fully controlled switch Q12; the emitter of fully controlled switch Q7 is connected to the cathode of diode D3 and the collector of fully controlled switch Q10, with the anode of diode D3 connected to the second terminal of resistor R1; the emitter of fully controlled switch Q10 is connected to the grid-side AC circuit and the collector of fully controlled switch Q13; the emitter of fully controlled switch Q11 is connected to the collector of fully controlled switch Q14 and the anode of diode D4, with the cathode of diode D4 connected to the second terminal of resistor R1. The emitter of the switching transistor Q14 is connected to the second terminal of the voltmeter; the emitter of the fully controlled switching transistor Q12 is connected to the collector of the fully controlled switching transistor Q15 and the anode of diode D5, the cathode of diode D5 is connected to the second terminal of resistor R1, and the emitter of the fully controlled switching transistor Q15 is connected to the second terminal of the voltmeter; the emitter of the fully controlled switching transistor Q13 is connected to the collector of the fully controlled switching transistor Q16 and the anode of diode D6, the cathode of diode D6 is connected to the second terminal of resistor R1, and the emitter of the fully controlled switching transistor Q16 is connected to the second terminal of the voltmeter.

[0038] The machine-side fully controlled device circuit includes fully controlled switching transistors Q17, Q18, Q19, Q20, Q21, Q22, Q23, Q24, Q25, Q26, Q27, and Q28; diodes D7, D8, D9, D10, D11, and D12; the collector of fully controlled switching transistor Q17; the collector of fully controlled switching transistor Q18; and the fully controlled... The collectors of switching transistor Q19 are all connected to the collector of fully controlled switching transistor Q2. The emitter of fully controlled switching transistor Q17 is connected to the collector of fully controlled switching transistor Q20. The emitter of fully controlled switching transistor Q20 is connected to the machine-side AC circuit, the collector of fully controlled switching transistor Q23, and the cathode of diode D7. The anode of diode D7 is connected to the second terminal of resistor R1. The emitter of fully controlled switching transistor Q18 is connected to the collector of fully controlled switching transistor Q21. The emitter of fully controlled switching transistor Q21 is connected to the machine-side AC circuit, the collector of fully controlled switching transistor Q24, and the cathode of diode D8. The positive terminal of transistor D8 is connected to the second terminal of resistor R1; the emitter of fully controlled switching transistor Q19 is connected to the collector of fully controlled switching transistor Q22, the emitter of fully controlled switching transistor Q22 is connected to the machine-side AC circuit, the collector of fully controlled switching transistor Q25 and the negative terminal of diode D9, and the positive terminal of diode D9 is connected to the second terminal of resistor R1; the collector of fully controlled switching transistor Q23 is also connected to the positive terminal of diode D10, the negative terminal of diode D10 is connected to the second terminal of resistor R1, the collector of fully controlled switching transistor Q24 is also connected to the positive terminal of diode D11, and the negative terminal of diode D11 is connected to... The collector of the fully controlled switching transistor Q25 is connected to the positive terminal of diode D12, and the negative terminal of diode D12 is connected to the second terminal of resistor R1. The emitter of the fully controlled switching transistor Q23 is connected to the collector of the fully controlled switching transistor Q26, the emitter of the fully controlled switching transistor Q24 is connected to the collector of the fully controlled switching transistor Q27, the emitter of the fully controlled switching transistor Q25 is connected to the collector of the fully controlled switching transistor Q28, and the emitters of the fully controlled switching transistors Q26, Q27, and Q28 are all connected to the second terminal of the voltmeter.

[0039] The grid-side AC circuit includes inductors L1, L2, and L3 connected in series on the three-phase lines of the power grid, and current transformers CT1, CT2, and CT3 installed on the three-phase lines of the power grid; the machine-side AC circuit includes inductors L4, L5, and L6 connected in series on the three-phase lines of the power grid, and current transformers CT4, CT5, and CT6 installed on the three-phase lines of the power grid.

[0040] The third terminal of the grid-side AC circuit is connected to the stator terminal of the doubly-fed induction generator. A normally open contact of a contactor for controlling the start and stop of the doubly-fed induction generator is connected in series between the third terminal of the grid-side AC circuit and the stator terminal of the doubly-fed induction generator. A voltage sensor is also installed between the normally open contact of the contactor and the third terminal of the grid-side AC circuit.

[0041] like Figure 2 As shown, the present invention provides a control method for a wind power converter based on any one of the above claims, comprising:

[0042] S1. Obtain the grid voltage of the three-phase line of the power grid, the DC voltage of the DC side circuit, the AC current of the grid side AC circuit, and the AC current of the machine side AC circuit; specifically, obtain the grid voltage of the three-phase line of the power grid using a voltage sensor, obtain the DC voltage of the DC side circuit using a voltmeter, obtain the AC current of the grid side AC circuit using current transformers CT1, CT4, CT5, and CT6, and obtain the AC current of the machine side AC circuit using current transformers CT4, CT5, and CT6.

[0043] S2. Compare the obtained grid voltage of the three-phase line with 0.8 times the rated voltage of the three-phase line of the grid, compare the obtained DC voltage of the DC side circuit with 1.3 times the rated DC voltage, compare the obtained AC current of the grid side AC circuit with 5 times the rated grid current, and compare the obtained AC current of the machine side AC circuit with 5 times the rated machine current.

[0044] S3. If the AC current of the grid-side AC circuit is greater than or equal to 5 times the grid-side rated current or the AC current of the generator-side AC circuit is greater than or equal to 5 times the generator-side rated current, and the grid voltage of the three-phase line of the grid is greater than or equal to 0.8 times the rated voltage of the three-phase line of the grid, and the DC voltage of the DC circuit is greater than or equal to 1.3 times the rated DC voltage, then it is determined that a short circuit fault has occurred in the DC circuit.

[0045] S4. Disconnect the fully controlled switching transistors Q1 and Q2 to block the connection between the DC side circuit and the grid side AC circuit, the machine side AC circuit, the grid side fully controlled device circuit, and the machine side fully controlled device circuit;

[0046] S5 triggers the chopper circuit to release energy.

[0047] Disconnecting the fully controlled switching transistors Q1 and Q2 blocks the connection between the DC-side circuit and the grid-side AC circuit, the machine-side AC circuit, the grid-side fully controlled device circuit, and the machine-side fully controlled device circuit. In fact, this is achieved by using the diodes connected in anti-parallel in the fully controlled switching transistors Q1 and Q2 to block the connection between the DC-side circuit and the grid-side AC circuit, the machine-side AC circuit, the grid-side fully controlled device circuit, and the machine-side fully controlled device circuit.

[0048] like Figure 3 As shown, traditional wind power converters have a slow energy discharge rate when a short-circuit fault occurs on the DC side, which is difficult to meet the requirements. Figure 4 As shown, the chopper circuit of the present invention can quickly discharge energy when a short circuit fault occurs on the DC side, ensuring the overall safety of the wind power converter.

[0049] The above-disclosed embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any non-creative variations that can be conceived by those skilled in the art, as well as any improvements and modifications made without departing from the principles of the present invention, should fall within the protection scope of the present invention.

Claims

1. A wind power converter, characterized in that include: Grid-side AC circuit, machine-side AC circuit, grid-side fully controlled device circuit, machine-side fully controlled device circuit, and DC-side circuit; The first end of the grid-side AC circuit is connected to the three-phase line of the power grid through a circuit breaker. The second end of the grid-side AC circuit is connected to the first end of the DC-side circuit through the grid-side fully controlled device circuit. The second end of the DC-side circuit is connected to the machine-side AC circuit through the machine-side fully controlled device circuit. The DC-side circuit includes fully controlled transistors Q1 and Q2, resistors R1 and R2, a chopper circuit, and a voltmeter. The chopper circuit includes resistors R3 and R4, capacitors C1 and C2, and fully controlled transistors Q3 and Q4. The collector of fully controlled transistor Q1 is connected to the grid-side fully controlled device circuit. The emitter of fully controlled transistor Q1 is connected to the first terminal of the voltmeter, and the second terminal of the voltmeter is connected to the grid-side fully controlled device circuit. The emitter of fully controlled transistor Q1 is connected to the first terminal of resistor R1, and the second terminal of resistor R1 is connected to the grid-side fully controlled device circuit, the machine-side fully controlled device circuit, and resistor R2. The first terminal of resistor R2 is connected to the second terminal of the voltmeter; capacitor C1 is connected in parallel across resistor R1, the first terminal of resistor R1 is connected to the collector of fully controlled switching transistor Q3 through resistor R3, and the emitter of fully controlled switching transistor Q3 is connected to the second terminal of resistor R1; capacitor C2 is connected in parallel across resistor R2, the first terminal of resistor R2 is connected to the collector of fully controlled switching transistor Q4 through resistor R4, and the emitter of fully controlled switching transistor Q4 is connected to the second terminal of resistor R2; the emitter of fully controlled switching transistor Q2 is connected to the emitter of fully controlled switching transistor Q1, and the collector of fully controlled switching transistor Q2 is connected to the machine-side fully controlled device circuit; The grid-side fully controlled device circuit includes fully controlled switching transistors Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15, and Q16, as well as diodes D1, D2, D3, D4, D5, and D6. The collectors of fully controlled transistors Q5, Q6, and Q7 are all connected to the collector of fully controlled transistor Q1. The emitter of fully controlled transistor Q5 is connected to the cathode of diode D1 and the collector of fully controlled transistor Q8. The anode of diode D1 is connected to the second terminal of resistor R1. The emitter of fully controlled transistor Q8 is connected to the AC grid circuit and the collector of fully controlled transistor Q11. The emitter of fully controlled transistor Q6 is connected to diode D2. The cathode of diode D2 is connected to the collector of fully controlled switch Q9, the anode of diode D2 is connected to the second terminal of resistor R1, the emitter of fully controlled switch Q9 is connected to the grid-side AC circuit and the collector of fully controlled switch Q12; the emitter of fully controlled switch Q7 is connected to the cathode of diode D3 and the collector of fully controlled switch Q10, the anode of diode D3 is connected to the second terminal of resistor R1, and the emitter of fully controlled switch Q10 is connected to the grid-side AC circuit and the collector of fully controlled switch Q13. The emitter of the fully controlled transistor Q11 is connected to the collector of the fully controlled transistor Q14 and the anode of diode D4. The cathode of diode D4 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q14 is connected to the second terminal of the voltmeter. The emitter of the fully controlled transistor Q12 is connected to the collector of the fully controlled transistor Q15 and the anode of diode D5. The cathode of diode D5 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q15 is connected to the second terminal of the voltmeter. The emitter of the fully controlled transistor Q13 is connected to the collector of the fully controlled transistor Q16 and the anode of diode D6. The cathode of diode D6 is connected to the second terminal of resistor R1. The emitter of the fully controlled transistor Q16 is connected to the second terminal of the voltmeter. The machine-side fully controlled device circuit includes fully controlled switching transistors Q17, Q18, Q19, Q20, Q21, Q22, Q23, Q24, Q25, Q26, Q27, and Q28, diodes D7, D8, D9, D10, D11, and D12; The collectors of fully controlled transistors Q17, Q18, and Q19 are all connected to the collector of fully controlled transistor Q2. The emitter of fully controlled transistor Q17 is connected to the collector of fully controlled transistor Q20. The emitter of fully controlled transistor Q20 is connected to the machine-side AC circuit, the collector of fully controlled transistor Q23, and the cathode of diode D7. The anode of diode D7 is connected to the second terminal of resistor R1. The emitter of fully controlled transistor Q18 is connected to the fully controlled transistor... The collector of the fully controlled switch Q21 and the emitter of the fully controlled switch Q21 are connected to the machine-side AC circuit. The collector of the fully controlled switch Q24 and the cathode of the diode D8 are connected to the cathode of the diode D8. The anode of the diode D8 is connected to the second terminal of the resistor R1. The emitter of the fully controlled switch Q19 is connected to the collector of the fully controlled switch Q22. The emitter of the fully controlled switch Q22 is connected to the machine-side AC circuit. The collector of the fully controlled switch Q25 and the cathode of the diode D9 are connected to the cathode of the diode D9. The anode of the diode D9 is connected to the second terminal of the resistor R1. The collector of the fully controlled switching transistor Q23 is also connected to the anode of diode D10, and the cathode of diode D10 is connected to the second terminal of resistor R1. The collector of the fully controlled switching transistor Q24 is also connected to the anode of diode D11, and the cathode of diode D11 is connected to the second terminal of resistor R1. The collector of the fully controlled switching transistor Q25 is also connected to the anode of diode D12, and the cathode of diode D12 is connected to the second terminal of resistor R1. The emitter of the fully controlled switching transistor Q23 is connected to the collector of the fully controlled switching transistor Q26. The emitter of the fully controlled switching transistor Q24 is connected to the collector of the fully controlled switching transistor Q27. The emitter of the fully controlled switching transistor Q25 is connected to the collector of the fully controlled switching transistor Q28. The emitters of the fully controlled switching transistors Q26, Q27, and Q28 are all connected to the second terminal of the voltmeter. The diodes connected in anti-parallel in fully controlled switching transistors Q1 and Q2 block the connection between the DC side circuit and the grid-side AC circuit, the machine-side AC circuit, the grid-side fully controlled device circuit, and the machine-side fully controlled device circuit.

2. A wind power converter according to claim 1, characterized in that, The grid-side AC circuit includes inductors L1, L2, and L3 connected in series on the three-phase lines of the power grid, and current transformers CT1, CT2, and CT3 installed on the three-phase lines of the power grid.

3. A wind power converter according to claim 1, characterized in that, The machine-side AC circuit includes inductors L4, L5, and L6 connected in series on the three-phase lines of the power grid, and current transformers CT4, CT5, and CT6 installed on the three-phase lines of the power grid.

4. A wind power converter according to claim 1, characterized in that, The third terminal of the grid-side AC circuit is connected to the stator terminal of the doubly-fed induction generator. A normally open contact of a contactor that controls the start and stop of the doubly-fed induction generator is also connected in series between the third terminal of the grid-side AC circuit and the stator terminal of the doubly-fed induction generator.

5. A wind power converter according to claim 4, characterized in that, A voltage sensor is also installed between the normally open contact of the contactor and the third terminal of the AC circuit on the grid side.

6. A control method for a wind power converter based on any one of claims 1-5, characterized in that, include: Obtain the grid voltage of the three-phase lines of the power grid, the DC voltage of the DC side circuit, the AC current of the grid side AC circuit, and the AC current of the machine side AC circuit; The obtained grid voltage of the three-phase line is compared with 0.8 times the rated voltage of the three-phase line of the grid; the obtained DC voltage of the DC side circuit is compared with 1.3 times the rated DC voltage; the obtained AC current of the grid side AC circuit is compared with 5 times the rated grid current; and the obtained AC current of the machine side AC circuit is compared with 5 times the rated machine current. If the AC current of the grid-side AC circuit is greater than or equal to 5 times the grid-side rated current or the AC current of the generator-side AC circuit is greater than or equal to 5 times the generator-side rated current, and the grid voltage of the three-phase line of the grid is greater than or equal to 0.8 times the rated voltage of the three-phase line of the grid, and the DC voltage of the DC-side circuit is greater than or equal to 1.3 times the rated DC voltage, then a short circuit fault is determined to have occurred in the DC-side circuit. Disconnect the fully controlled switching transistors Q1 and Q2 to block the connection between the DC side circuit and the grid side AC circuit, the machine side AC circuit, the grid side fully controlled device circuit, and the machine side fully controlled device circuit; Trigger the chopper circuit to release energy.

7. The control method according to claim 6, characterized in that, The grid voltage of the three-phase lines of the power grid is obtained using a voltage sensor, the DC voltage of the DC side circuit is obtained using a voltmeter, the AC current of the grid-side AC circuit is obtained using current transformers CT1, CT4, CT5, and CT6, and the AC current of the machine-side AC circuit is obtained using current transformers CT4, CT5, and CT6.

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