Grid-connected loop system and control method for wind turbine generator set

Abstract

The grid-connected circuit system and control method of the wind turbine proposed in the present application, wherein the system includes: a current transformer, a grid-connected operation parameter monitoring device, a main control system and a stator contactor; the current transformer is used to collect the real-time current value of the wind turbine and send the real-time current value to the grid-connected operation parameter monitoring device; the grid-connected operation parameter monitoring device is used to determine whether the wind turbine is abnormal according to the real-time current value, and when the wind turbine is abnormal, determine the operation instruction based on the real-time current value, and then send the operation instruction to the main control system; the main control system is used to control the stator contactor to disconnect according to the operation instruction; the stator contactor is used to respond to the control of the main control system. The technical solution proposed in the present application eliminates the hidden dangers of the stator contactor and improves the safety and stability of the grid-connected operation of the wind turbine.

Description

Technical Field

[0001] The present application relates to the technical field of wind turbine grid connection, and in particular to a grid connection loop system and a control method for a wind turbine grid connection. Background Art

[0002] The grid-connected process of wind turbines has its own characteristics. When the unit reaches the grid-connected speed, the main controller sends a grid-connected command to the stator contactor, the stator contactor is energized, and the unit is connected to the grid for power generation. Due to the early design ideas of wind turbines and the limitations of the technical conditions at the time, the grid-connected circuit of wind turbines has inherent defects. In addition, with the increase in the operating years, problems will be exposed, mainly reflected in: First, the stator contactor has a weak ability to break large currents. When there is a shutdown during high-power operation, the stator contactor will stick; second, the stator contactor will spark and burn after a long operation time. Since the stator contactor is installed in the cabin, there are many combustibles such as oil, cables, etc., which may even cause fire accidents in serious cases; third, the stator contactor is installed in the cabin, which brings inconvenience to the operation and maintenance personnel. It is necessary to climb the tower to check to deal with related problems, which increases the workload and the danger, that is, the stability of the wind turbine grid-connected circuit is poor and there are safety hazards. Summary of the invention

[0003] The grid-connected circuit system and control method of a wind turbine set provided in the present application are intended to at least solve the technical problems in the related art that the grid-connected circuit of a wind turbine set has poor stability and potential safety hazards.

[0004] The first embodiment of the present application provides a grid-connected circuit system for a wind turbine generator set, comprising: a current transformer, a grid-connected operation parameter monitoring device, a main control system and a stator contactor;

[0005] The current transformer is used to collect the real-time current value of the wind turbine and send the real-time current value to the grid-connected operation parameter monitoring device;

[0006] The grid-connected operation parameter monitoring device is used to determine whether the wind turbine generator set is abnormal according to the real-time current value, determine an operation instruction based on the real-time current value when the wind turbine generator set is abnormal, and then send the operation instruction to the main control system;

[0007] The main control system is used to control the stator contactor to disconnect according to the operation instruction;

[0008] The stator contactor is used to respond to the control of the main control system.

[0009] Preferably, the grid-connected circuit system further comprises: a grid-connected cabinet and a circuit breaker;

[0010] The current transformer, the grid-connected operation parameter monitoring device, the stator contactor and the circuit breaker are all arranged in the grid-connected cabinet;

[0011] The main control system is further used to control the circuit breaker to disconnect according to the operation instruction;

[0012] The circuit breaker is used to respond to the control of the main control system.

[0013] Furthermore, when the wind turbine generator set is abnormal, determining an operation instruction based on the real-time current value, and then sending the operation instruction to the main control system includes:

[0014] When the real-time current value is greater than a preset alarm current threshold, less than or equal to a preset quick-break current threshold, and the duration is greater than a preset alarm current duration threshold, an operation instruction to disconnect the stator contactor is sent to the main control system;

[0015] When the real-time current value is greater than a preset quick-break current threshold, an operation instruction to disconnect the circuit breaker is sent to the main control system.

[0016] Furthermore, the main control system is also used to send a first blade retraction instruction or a second blade retraction instruction to the wind turbine set.

[0017] Further, when the main control system receives the operation instruction to disconnect the stator contactor, the main control system first sends a first blade retraction instruction to the wind turbine generator set, and then sends the operation instruction to disconnect the stator contactor to the stator contactor;

[0018] When the main control system receives the operation instruction to disconnect the circuit breaker, the main control system first sends a second blade retraction instruction to the wind turbine, and then sends the operation instruction to disconnect the circuit breaker to the circuit breaker after a second preset time has passed since the second blade retraction instruction was sent;

[0019] Among them, the propeller retraction time corresponding to the first propeller retraction instruction is greater than the propeller retraction time corresponding to the second propeller retraction instruction.

[0020] Furthermore, the stator contactor is further configured to send a non-disconnection signal to the main control system when adhesion occurs after receiving the operation instruction to disconnect the stator contactor;

[0021] The main control system is also used to receive the signal and send an operation instruction to disconnect the circuit breaker to the circuit breaker.

[0022] Furthermore, the grid-connected operation parameter monitoring device is also used to monitor the connection status of the stator contactor and the circuit breaker.

[0023] Furthermore, the grid-connected loop system further comprises: a voltage transformer, wherein the voltage transformer is arranged in the grid-connected cabinet;

[0024] The voltage transformer is used to collect the real-time voltage value of the wind turbine and send the real-time voltage value to the grid-connected operation parameter monitoring device;

[0025] The grid-connected operation parameter monitoring device is also used to receive the real-time voltage value and determine whether the wind turbine generator set is abnormal based on the real-time voltage value.

[0026] Furthermore, the grid-connected loop system further comprises: a temperature and humidity control system and an automatic fire extinguishing system, wherein the humidity control system and the automatic fire extinguishing system are both arranged in the grid-connected cabinet;

[0027] The temperature and humidity control system is used to monitor the temperature and humidity in the power cabinet, and when it is monitored that the temperature in the power cabinet is higher than a preset maximum temperature threshold or lower than a preset minimum temperature threshold, heat dissipation or heating is performed; when it is monitored that the humidity in the power cabinet is higher than a preset maximum humidity threshold or lower than a preset minimum humidity threshold, dehumidification or humidification is performed;

[0028] The automatic fire extinguishing system is used to monitor whether there is a flame in the grid-connected cabinet, and when a flame is detected in the grid-connected cabinet, a fire extinguishing bomb is activated to extinguish the fire.

[0029] A second aspect of the present application provides a control method for a grid-connected circuit system of a wind turbine generator set, the method comprising:

[0030] Use current transformers to collect real-time current values ​​of wind turbines;

[0031] The grid-connected operation parameter monitoring device determines whether the wind turbine generator set is abnormal according to the real-time current value, and determines an operation instruction based on the real-time current value when the wind turbine generator set is abnormal;

[0032] The main control system controls the stator contactor or circuit breaker to disconnect according to the operation instruction.

[0033] The technical solution provided by the embodiments of the present application brings at least the following beneficial effects:

[0034] The present application proposes a grid-connected circuit system and control method for a wind turbine, wherein the system includes: a current transformer, a grid-connected operation parameter monitoring device, a main control system and a stator contactor; the current transformer is used to collect the real-time current value of the wind turbine and send the real-time current value to the grid-connected operation parameter monitoring device; the grid-connected operation parameter monitoring device is used to determine whether the wind turbine is abnormal based on the real-time current value, and when the wind turbine is abnormal, determine an operation instruction based on the real-time current value, and then send the operation instruction to the main control system; the main control system is used to control the stator contactor to disconnect according to the operation instruction; the stator contactor is used to respond to the control of the main control system. The technical solution proposed in the present application uses the grid-connected operation parameter monitoring device to determine whether the wind turbine is abnormal based on the real-time current value, and issue an operation instruction according to the abnormal situation, thereby eliminating the hidden dangers of the stator contactor and improving the safety and stability of the grid-connected operation of the wind turbine.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0037] Figure 1 A block diagram of a grid-connected loop system of a wind turbine generator set provided according to an embodiment of the present application;

[0038] Figure 2 A first structural diagram of a grid-connected circuit system of a wind turbine generator set provided according to an embodiment of the present application;

[0039] Figure 3 A second structural diagram of a grid-connected circuit system of a wind turbine generator set provided according to an embodiment of the present application;

[0040] Figure 4 A schematic diagram of an early wind turbine grid-connected circuit system provided according to an embodiment of the present application;

[0041] Figure 5 A schematic diagram of a modified wind turbine grid-connected circuit system provided according to an embodiment of the present application;

[0042] Figure 6 An operation flow chart of a grid-connected loop system of a wind turbine generator set provided according to an embodiment of the present application;

[0043] Figure 7A flow chart of a control method for a grid-connected loop system of a wind turbine generator set provided according to an embodiment of the present application; Description of the drawings:

[0045] Current transformer 1, grid-connected operation parameter monitoring device 2, main control system 3, stator contactor 4, grid-connected cabinet 5, circuit breaker 6, voltage transformer 7, temperature and humidity control system 8, automatic fire extinguishing system 9. DETAILED DESCRIPTION

[0046] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0047] The grid-connected circuit system and control method of the wind turbine proposed in the present application, wherein the system includes: a current transformer, a grid-connected operation parameter monitoring device, a main control system and a stator contactor; the current transformer is used to collect the real-time current value of the wind turbine and send the real-time current value to the grid-connected operation parameter monitoring device; the grid-connected operation parameter monitoring device is used to determine whether the wind turbine is abnormal based on the real-time current value, and when the wind turbine is abnormal, determine the operation instruction based on the real-time current value, and then send the operation instruction to the main control system; the main control system is used to control the stator contactor to disconnect according to the operation instruction; the stator contactor is used to respond to the control of the main control system. The technical solution proposed in the present application uses the grid-connected operation parameter monitoring device to determine whether the wind turbine is abnormal based on the real-time current value, and issue an operation instruction according to the abnormal situation, thereby eliminating the hidden dangers of the stator contactor and improving the safety and stability of the grid-connected operation of the wind turbine.

[0048] The following describes a grid-connected circuit system and a control method for a wind turbine generator set according to an embodiment of the present application with reference to the accompanying drawings.

[0049] Example 1

[0050] Figure 1 A block diagram of a grid-connected loop system of a wind turbine generator set provided according to an embodiment of the present application is shown in FIG. Figure 1 As shown, the system includes: a current transformer 1, a grid-connected operation parameter monitoring device 2, a main control system 3 and a stator contactor 4;

[0051] The current transformer 1 is used to collect the real-time current value of the wind turbine and send the real-time current value to the grid-connected operation parameter monitoring device 2;

[0052] The grid-connected operation parameter monitoring device 2 is used to determine whether the wind turbine generator set is abnormal according to the real-time current value, determine an operation instruction based on the real-time current value when the wind turbine generator set is abnormal, and then send the operation instruction to the main control system 3;

[0053] The main control system 3 is used to control the stator contactor 4 to disconnect according to the operation instruction;

[0054] The stator contactor 4 is used to respond to the control of the main control system 3 .

[0055] In the embodiments of the present disclosure, Figure 2 As shown, the grid-connected circuit system further includes: a grid-connected cabinet 5 and a circuit breaker 6;

[0056] The current transformer 1, the grid-connected operation parameter monitoring device 2, the stator contactor 4 and the circuit breaker 6 are all arranged in the grid-connected cabinet 5, and the grid-connected cabinet 5 is arranged at the tower base;

[0057] The main control system 3 is also used to control the circuit breaker 6 to disconnect according to the operation instruction;

[0058] The circuit breaker 6 is used to respond to the control of the main control system 3 .

[0059] It should be noted that the original stator contactor 4 is moved from the cabin to the grid cabinet 5, away from the fire source, eliminating the fire hazard in the cabin; at the same time, the grid cabinet 5 is placed at the tower base, which reduces the burden of operation and maintenance personnel in dealing with such faults, and there is no need to enter the cabin to eliminate the fault.

[0060] It should be noted that when the wind turbine generator set is abnormal, determining the operation instruction based on the real-time current value, and then sending the operation instruction to the main control system 3, includes:

[0061] When the real-time current value is greater than the preset alarm current threshold, less than or equal to the preset quick-break current threshold and the duration is greater than the preset alarm current duration threshold, an operation instruction to disconnect the stator contactor 4 is sent to the main control system 3;

[0062] When the real-time current value is greater than the preset quick-break current threshold, an operation instruction to disconnect the circuit breaker 6 is sent to the main control system 3 .

[0063] Among them, the alarm current threshold can be 1.2-1.5 times of the rated current, the quick-break current threshold can be 4-5 times of the rated current, and the alarm current duration threshold can be 10-20s.

[0064] In the disclosed embodiment, the main control system 3 is further used to send a first blade folding instruction or a second blade folding instruction to the wind turbine set, and the blade folding time corresponding to the first blade folding instruction is greater than the blade folding time corresponding to the second blade folding instruction.

[0065] When the main control system 3 receives the operation instruction to disconnect the stator contactor 4, the main control system 3 first sends a first blade retraction instruction to the wind turbine, and then sends the operation instruction to disconnect the stator contactor 4 to the stator contactor 4;

[0066] When the main control system 3 receives the operation instruction to disconnect the circuit breaker 6, the main control system 3 first sends a second blade retraction instruction to the wind turbine set, and then sends the operation instruction to disconnect the circuit breaker 6 to the circuit breaker 6 after a second preset time has passed since the second blade retraction instruction was sent; wherein the second preset time may be within 0.5s.

[0067] Furthermore, the stator contactor 4 is also used to send a non-disconnection signal to the main control system 3 when adhesion occurs after receiving the operation instruction to disconnect the stator contactor 4;

[0068] The main control system 3 is also used to receive the signal and send an operation instruction to the circuit breaker 6 to disconnect the circuit breaker 6.

[0069] It should be noted that, through the cooperation of the stator contactor 4 and the circuit breaker 6, the shutdown protection logic when the current is too large is optimized, achieving the effect of two-level protection, preventing further damage to the unit due to the failure of the stator contactor 4 to disconnect in time; at the same time, a protection program to prevent the wind turbine from running away is added to the shutdown logic, avoiding running away accidents caused by sudden power failure of the unit under heavy load, and protecting the unit more comprehensively.

[0070] In the disclosed embodiment, the grid-connected operation parameter monitoring device 2 is also used to monitor the connection status of the stator contactor 4 and the circuit breaker 6.

[0071] In the embodiments of the present disclosure, Figure 3 As shown, the grid-connected loop system further includes: a voltage transformer 7, and the voltage transformer 7 is arranged in the grid-connected cabinet 5;

[0072] The voltage transformer 7 is used to collect the real-time voltage value of the wind turbine and send the real-time voltage value to the grid-connected operation parameter monitoring device 2;

[0073] The grid-connected operation parameter monitoring device 2 is also used to receive the real-time voltage value, and determine whether the wind turbine generator set is abnormal based on the real-time voltage value.

[0074] In the embodiments of the present disclosure, Figure 3 As shown, the grid-connected loop system further includes: a temperature and humidity control system 8 and an automatic fire extinguishing system 9, and the humidity control system 8 and the automatic fire extinguishing system 9 are both arranged in the grid-connected cabinet 5;

[0075] The temperature and humidity control system 8 is used to monitor the temperature and humidity in the power cabinet 5. When it is monitored that the temperature in the power cabinet 5 is higher than the preset maximum temperature threshold or lower than the preset minimum temperature threshold, heat dissipation or heating is performed; when it is monitored that the humidity in the power cabinet 5 is higher than the preset maximum humidity threshold or lower than the preset minimum humidity threshold, dehumidification or humidification is performed;

[0076] The automatic fire extinguishing system 9 is used to monitor whether there is a flame in the power cabinet 5. When a flame is detected in the power cabinet 5, the fire extinguishing bomb is activated to extinguish the fire.

[0077] It should be noted that when the system provided in the application is applied to the grid connection of early wind turbines, the stator contactor 4 needs to be removed from the cabin position, and the original position is connected with a copper busbar with qualified current carrying capacity. The removed stator contactor 4 is installed in the newly added grid cabinet 5. At the same time, the power line and signal feedback line of the original stator contactor 4 are led down from the cabin; after the current transformer 1, the grid operation parameter monitoring device 2, the stator contactor 4, the circuit breaker 6, the voltage transformer 7, the temperature and humidity control system 8 and the automatic fire extinguishing system 9 are installed in the grid cabinet 5, the relevant signal feedback line and the action control signal line are connected to the main control system 3, which mainly includes feedback on whether the current is over-limit, feedback on the opening and closing of the stator contactor 4, feedback on the opening and closing of the circuit breaker 6, and the control signal of the circuit breaker 6 executing the disconnection action, among which, Figure 4 This is a schematic diagram of the early wind turbine grid-connected circuit system, including: power grid, box transformer circuit breaker, fuse, network test contactor, converter, generator and stator contactor. The connection relationship between each component is as follows Figure 4 As shown, the stator contactor 4 is installed in the nacelle corresponding to the wind turbine set; Figure 5 The modified wind turbine grid-connected circuit system of this scheme adds a current transformer 1, a grid-connected operation parameter monitoring device 2, a main control system 3, a grid-connected cabinet 5, a circuit breaker 6, a voltage transformer 7, a temperature and humidity control system 8, an automatic fire extinguishing system 9, and a stator contactor 4 is arranged in the grid-connected cabinet 5. The connection relationship of each component is as follows: Figure 5 shown.

[0078] For example, Figure 6The figure shows the operation flow chart of the grid-connected loop system of the wind turbine generator set. The grid-connected operation parameter monitoring device 2 monitors the current value of the wind turbine generator set in real time. When the current value is normal, it indicates that the wind turbine generator set is operating normally and continues to monitor. When the current of the wind turbine generator set is abnormal, the grid-connected operation parameter monitoring device 2 makes a judgment and sends a relevant signal to the main control system 3. The main control system 3 makes a corresponding action instruction to the unit, as follows:

[0079] Determine whether the current value exceeds the preset quick-break current threshold C2. If so, the grid-connected operation parameter monitoring device 2 directly sends a shutdown signal to the main control system 3. After receiving the signal, the main control system 3 first issues an emergency blade retraction command (faster than the rapid blade retraction) (the reason for performing rapid blade retraction first is to prevent the stator contactor or circuit breaker from being suddenly disconnected, and the blades are not retracted, causing a runaway accident). After the second preset time T2, there is no need to go through the stator contactor 4, and a disconnection command is directly sent to the circuit breaker 6 to disconnect the entire grid-connected circuit and shut down the wind turbine. In this case, the role of the second preset time is to leave time for the main control system 3 to issue an emergency blade retraction command.

[0080] Otherwise, determine whether the real-time current value is greater than the preset alarm current threshold C1 and the duration is greater than the preset alarm current duration threshold T1. If not, the normal operation of the wind turbine continues to be monitored. If so, the grid-connected operation parameter monitoring device 2 makes a judgment and sends a shutdown signal to the main control system 3. After receiving the signal, the main control system 3 first issues a command to quickly retract the blades (the reason for quickly retracting the blades first is to prevent the stator contactor or circuit breaker from being suddenly disconnected, and the blades are not retracted to cause a runaway accident), and then issues a disconnection operation instruction, that is, a shutdown instruction, to the stator contactor 4. At this time, the grid-connected operation parameter monitoring device 2 monitors the opening and closing state of the stator contactor 4 to determine whether the stator contactor 4 is disconnected. If it is not released for a long time, that is, the switch is not disconnected, then the stator contactor 4 also feeds back a signal to the main control system 3, and the main control system 3 immediately sends a disconnection instruction to the circuit breaker 6 to disconnect the entire grid-connected circuit.

[0081] To sum up, the grid-connected circuit system of a wind turbine set proposed in this embodiment eliminates the hidden dangers of the stator contactor and improves the safety and stability of the grid-connected operation of the wind turbine set. At the same time, this scheme is scientific and reasonable and has good economic efficiency, strong practical significance, and has important guiding significance for the transformation and optimization of old wind turbine sets.

[0082] Example 2

[0083] Figure 7 Flow chart of a control method for a grid-connected loop system of a wind turbine generator set provided according to one embodiment of the present application, such as Figure 7 As shown, the method includes:

[0084] Step 1: Use current transformer to collect the real-time current value of wind turbine;

[0085] Step 2: The grid-connected operation parameter monitoring device determines whether the wind turbine generator set is abnormal according to the real-time current value, and determines an operation instruction based on the real-time current value when the wind turbine generator set is abnormal;

[0086] Step 3: The main control system controls the stator contactor or circuit breaker to disconnect according to the operation instruction.

[0087] In the disclosed embodiment, the grid-connected operation parameter monitoring device monitors the current value of the wind turbine set in real time. When the current value is normal, it indicates that the wind turbine set is operating normally and continues to monitor. When the current of the wind turbine set is abnormal, the grid-connected operation parameter monitoring device makes a judgment and sends a relevant signal to the main control system. The main control system issues a corresponding action instruction to the unit, which is as follows:

[0088] Determine whether the current value exceeds the preset quick-break current threshold C2. If so, the grid-connected operation parameter monitoring device directly sends a shutdown signal to the main control system. After receiving the signal, the main control system first issues an emergency blade retraction command (faster than rapid blade retraction) (the reason for rapid blade retraction first is to prevent the stator contactor or circuit breaker from being suddenly disconnected, and the blades are not retracted, resulting in a runaway accident). After the second preset time T2, the circuit breaker is directly issued a disconnect command without going through the stator contactor, disconnecting the entire grid-connected circuit and shutting down the wind turbine. In this case, the role of the second preset time is to give the main control system time to issue an emergency blade retraction command.

[0089] Otherwise, determine whether the real-time current value is greater than the preset alarm current threshold C1 and the duration is greater than the preset alarm current duration threshold T1. If not, the normal operation of the wind turbine continues to be monitored. If so, the grid-connected operation parameter monitoring device makes a judgment and sends a shutdown signal to the main control system. After receiving the signal, the main control system first issues a command to quickly retract the blades (the reason for quickly retracting the blades first is to prevent the stator contactor or circuit breaker from being suddenly disconnected, and the blades are not retracted and a runaway accident occurs). Then, a disconnection operation instruction, i.e., a shutdown instruction, is issued to the stator contactor. At this time, the grid-connected operation parameter monitoring device monitors the opening and closing state of the stator contactor to determine whether the stator contactor is disconnected. If it is not released for a long time, that is, the switch is not disconnected, then the stator contactor also feeds back a signal to the main control system, and the main control system immediately sends a disconnection instruction to the circuit breaker to disconnect the entire grid-connected loop.

[0090] In summary, the control method of the grid-connected circuit system of a wind turbine set proposed in this embodiment eliminates the hidden dangers of the stator contactor and improves the safety and stability of the grid-connected operation of the wind turbine set.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0092] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0093] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A grid-connected circuit system for a wind turbine generator set, characterized in that: include: Current transformer, grid-connected operation parameter monitoring device, main control system and stator contactor; The current transformer is used to collect the real-time current value of the wind turbine and send the real-time current value to the grid-connected operation parameter monitoring device; The grid-connected operation parameter monitoring device is used to determine whether the wind turbine generator set is abnormal according to the real-time current value, determine an operation instruction based on the real-time current value when the wind turbine generator set is abnormal, and then send the operation instruction to the main control system; The main control system is used to control the stator contactor to disconnect according to the operation instruction; The stator contactor is used to respond to the control of the main control system; The grid-connected circuit system also includes: a grid-connected cabinet and a circuit breaker; The current transformer, the grid-connected operation parameter monitoring device, the stator contactor and the circuit breaker are all arranged in the grid-connected cabinet; The main control system is further used to control the circuit breaker to disconnect according to the operation instruction; The circuit breaker is used to respond to the control of the main control system; When the wind turbine generator set is abnormal, determining an operation instruction based on the real-time current value, and then sending the operation instruction to the main control system, comprises: When the real-time current value is greater than a preset alarm current threshold, less than or equal to a preset quick-break current threshold, and the duration is greater than a preset alarm current duration threshold, an operation instruction to disconnect the stator contactor is sent to the main control system; When the real-time current value is greater than a preset quick-break current threshold, an operation instruction for disconnecting the circuit breaker is sent to the main control system; The main control system is further used to send a first blade retraction instruction or a second blade retraction instruction to the wind turbine generator set; When the main control system receives the operation instruction to disconnect the stator contactor, the main control system first sends a first blade retraction instruction to the wind turbine generator set, and then sends the operation instruction to disconnect the stator contactor to the stator contactor; When the main control system receives the operation instruction to disconnect the circuit breaker, the main control system first sends a second blade retraction instruction to the wind turbine, and then sends the operation instruction to disconnect the circuit breaker to the circuit breaker after a second preset time has passed since the second blade retraction instruction was sent; Among them, the propeller retraction time corresponding to the first propeller retraction instruction is greater than the propeller retraction time corresponding to the second propeller retraction instruction.

2. The system according to claim 1, characterized in that The stator contactor is further configured to send a non-disconnection signal to the main control system when adhesion occurs after receiving the operation instruction to disconnect the stator contactor; The main control system is also used to receive the signal and send an operation instruction to disconnect the circuit breaker to the circuit breaker.

3. The system according to claim 2, characterized in that The grid-connected operation parameter monitoring device is also used to monitor the connection status of the stator contactor and the circuit breaker.

4. The system according to claim 2, characterized in that The grid-connected loop system further includes: a voltage transformer, which is arranged in the grid-connected cabinet; The voltage transformer is used to collect the real-time voltage value of the wind turbine and send the real-time voltage value to the grid-connected operation parameter monitoring device; The grid-connected operation parameter monitoring device is also used to receive the real-time voltage value and determine whether the wind turbine generator set is abnormal based on the real-time voltage value.

5. The system according to claim 2, characterized in that The grid-connected loop system further includes: a temperature and humidity control system and an automatic fire extinguishing system, wherein the humidity control system and the automatic fire extinguishing system are both arranged in the grid-connected cabinet; The temperature and humidity control system is used to monitor the temperature and humidity in the power cabinet, and when it is monitored that the temperature in the power cabinet is higher than a preset maximum temperature threshold or lower than a preset minimum temperature threshold, heat dissipation or heating is performed; when it is monitored that the humidity in the power cabinet is higher than a preset maximum humidity threshold or lower than a preset minimum humidity threshold, dehumidification or humidification is performed; The automatic fire extinguishing system is used to monitor whether there is a flame in the grid-connected cabinet, and when a flame is detected in the grid-connected cabinet, a fire extinguishing bomb is activated to extinguish the fire.

6. A control method for a grid-connected circuit system of a wind turbine generator set based on any one of claims 1 to 5, characterized in that: The method comprises: Use current transformers to collect real-time current values ​​of wind turbines; The grid-connected operation parameter monitoring device determines whether the wind turbine generator set is abnormal according to the real-time current value, and determines an operation instruction based on the real-time current value when the wind turbine generator set is abnormal; The main control system controls the stator contactor or circuit breaker to disconnect according to the operation instruction.

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