Grid-forming wind turbine startup process control method, system, medium and equipment

Abstract

The present invention discloses a control method, system, medium and device for the start-up process of a grid-forming wind turbine, including a standby state, a start-up state, a speed-up state and a grid-connection state. This method details the logic of the whole machine start-up process, can effectively solve the technical problems existing in the start-up process of large-scale grid-forming wind turbines, and without the need to additionally increase equipment by adopting the present invention, the unit itself is used as a synchronous power source, which can solve the problem of grid stability for large-scale wind power grid connection and has good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of the start-up and grid connection process control of grid-forming wind turbines, and in particular to a start-up process control method, system, storage medium and computing device for grid-forming wind turbines. Background Art

[0002] When new energy sources such as wind turbines are connected to the power grid, the proportion of synchronous power sources that can form the power grid in the system will decrease, resulting in potential safety and stability risks in the operation of the power grid. In particular, current wind turbines all exhibit grid-connected characteristics of drawing power from the grid and cannot effectively support the power grid in a new power system with a high proportion of new energy stations. Therefore, developing wind turbines with grid-forming grid-connected characteristics has become an urgent problem to be solved in the industry. Summary of the Invention

[0003] The first object of the present invention is to overcome the deficiencies of the prior art and provide a start-up process control method for grid-forming wind turbines, which is used to solve the start-up and grid connection process control of grid-forming wind turbines and utilize the wind turbines themselves as synchronous power sources to form the power grid.

[0004] The second object of the present invention is to provide a start-up process control system for grid-forming wind turbines.

[0005] The third object of the present invention is to provide a storage medium.

[0006] The fourth object of the present invention is to provide a computing device.

[0007] The first object of the present invention is achieved by the following technical solutions: A start-up process control method for grid-forming wind turbines, comprising the following steps:

[0008] 1) Standby state:

[0009] After the unit is powered on, it performs self-check. When there is no fault after the self-check, the start button is pressed. The main control system of the unit sends a request for closing the machine-side circuit breaker to the full-power converter. The full-power converter executes the instruction for closing the machine-side circuit breaker. After the machine-side circuit breaker is closed, it feeds back a signal indicating that the machine-side circuit breaker has been closed to the main control system. After receiving the signal indicating that the machine-side circuit breaker has been closed, the unit enters the start-up state;

[0010] 2) Start-up state:

[0011] The main control system sends an instruction to the pitch system to pitch the blades to the pitch angle Angle1 in the start-up state. The machine-side rectifier of the full-power converter performs modulation and executes DC bus control, and determines whether the following conditions are met: whether the generator speed reaches the target value RPM1 in the speed-up state and exceeds the preset time, and whether the DC bus voltage reaches the set value U dc.refAnd if the preset time is exceeded, if the conditions are met simultaneously, the unit enters the speed-up state; otherwise, it remains in the starting state.

[0012] 3) Speed-up state:

[0013] The main control system sends a pitch-changing command to the pitch-changing system to pitch the blades to the minimum pitch angle Angle2. The machine-side rectifier of the full-power converter is modulated, and it is judged whether the following conditions are met: whether the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and whether the detected grid-side voltage is greater than or equal to K × the rated positive-sequence grid voltage, where the coefficient k is not greater than 1 and its value is determined according to the dynamic characteristics of the full-power converter. If the conditions are met simultaneously, the unit enters the normal starting process of the grid-connected state; otherwise, it is necessary to further judge whether the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and the detected grid-side voltage is less than K × the rated positive-sequence grid voltage. If both are met, the unit enters the build-up voltage starting process of the grid-connected state. Subsequently, it is detected whether the electromagnetic speed reaches the target value RPM3 and exceeds the preset time. If it is met, the unit enters the grid-connected state; otherwise, the unit remains in the starting state.

[0014] 4) Grid-connected state:

[0015] The main control system sends a synchronization command, a torque set value, and a reactive power set value to the full-power converter. The main control system performs constant-speed control and sends a pitch angle command to the pitch-changing system according to the control result of the original speed controller. After receiving the synchronization command during the normal starting process of the full-power converter, it closes its grid-side circuit breaker. After the closing is completed, it sends a completion-of-closing command to the main control system. The grid side executes the virtual synchronous machine algorithm and executes modulation to start running at the torque set value and reactive power set value of the main control system. After receiving the synchronization command during the build-up voltage starting process of the full-power converter, it issues a command to enter the self-built voltage state to internally generate the grid reference phase angle and voltage reference value, and executes modulation to build up the voltage. Subsequently, it is judged whether the grid-connected voltage reaches the set value and the grid-connected power exceeds 0 kW and exceeds the preset time. If it is met, the full-power converter enters the AC SOURCE state; otherwise, it continues to wait.

[0016] Furthermore, in step 2), the DC bus voltage is the voltage across the DC bus support capacitor of the full-power converter, which is obtained by internal calculation through acquisition by the converter controller of the full-power converter; the generator speed is the generator electromagnetic speed obtained by the full-power converter according to the acquisition and calculation of the generator terminal voltage, and can also be obtained by the main control system according to the acquisition and calculation of the generator proximity switch.

[0017] Furthermore, in step 4), the AC SOURCE state means that the full-power converter controls the output voltage to be the rated grid-connected voltage value and controls the grid-connected frequency to be the industrial frequency of 50 / 60 Hz.

[0018] The second object of the present invention is achieved by the following technical solution: A grid-forming wind turbine startup process control system, comprising:

[0019] A standby module, which performs self-checking after the unit is powered on. When the start button is pressed in the fault-free state after the self-checking is completed, a request for closing the machine-side circuit breaker is sent to the full-power converter through the main control system of the unit. The full-power converter executes the machine-side circuit breaker closing instruction. After the machine-side circuit breaker completes the closing, a signal indicating that the machine-side circuit breaker has completed the closing is fed back to the main control system. After the main control system receives the signal indicating that the machine-side circuit breaker has completed the closing, the unit enters the startup state;

[0020] A startup module, which sends an instruction to the pitch system through the main control system to pitch the blades to the startup-state pitch angle Angle1. The machine-side rectifier of the full-power converter performs modulation and executes DC bus control, and judges whether the following conditions are met: whether the generator speed reaches the target value RPM1 of the speed-up state and exceeds the preset time, and whether the DC bus voltage reaches the set value U dc.ref and exceeds the preset time. If both conditions are met, the unit enters the speed-up state; otherwise, it remains in the startup state;

[0021] A speed-up module, which sends a pitch-to-minimum-position instruction to the pitch system through the main control system to pitch the blades to the minimum blade pitch angle Angle2. The machine-side rectifier of the full-power converter performs modulation, and judges whether the following conditions are met: whether the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and whether the detected grid-side voltage is greater than or equal to K × the rated positive-sequence grid voltage, where the coefficient k is not greater than 1 and its value is determined according to the dynamic characteristics of the full-power converter. If both conditions are met, the unit enters the normal startup process of the grid-connected state; otherwise, it is necessary to further judge whether both the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and the detected grid-side voltage is less than K × the rated positive-sequence grid voltage. If both are met, the unit enters the build-up voltage startup process of the grid-connected state. Subsequently, it is detected whether the electromagnetic speed reaches the target value RPM3 and exceeds the preset time. If it is met, the unit enters the grid-connected state; otherwise, the unit remains in the startup state;

[0022] The grid-connection module sends synchronization commands, torque set values, and reactive power set values to the full-power converter through the main control system. The main control system performs constant-speed control and sends pitch angle commands to the pitch system according to the control results of the original speed controller. After receiving the synchronization command during the normal startup process of the full-power converter, it closes its grid-side circuit breaker. After the closing is completed, it sends a completion closing command to the main control system. The grid side executes the virtual synchronous machine algorithm and executes modulation startup to operate at the torque set value and reactive power set value of the main control system. During the voltage build-up startup process of the full-power converter, after receiving the synchronization command, it sends a signal to enter the state of self-building voltage, internally generates the grid reference phase angle and voltage reference value, and executes modulation voltage build-up. Then it judges whether the grid-connected voltage reaches the set value, the grid-connected power exceeds 0 kW and exceeds the preset time. If satisfied, the full-power converter enters the AC SOURCE state; otherwise, it continues to wait.

[0023] Further, in the startup module, the DC bus voltage is the voltage across the DC bus support capacitor of the full-power converter, which is obtained by internal calculation through acquisition by the converter controller of the full-power converter; the generator speed can be obtained by the full-power converter according to the generator electromagnetic speed calculated by collecting the generator terminal voltage, or can also be obtained by the main control system according to the generator proximity switch collection and calculation.

[0024] Further, in the grid-connection module, the AC SOURCE state means that the full-power converter controls the output voltage to be the rated grid-connected voltage and controls the grid-connected frequency to be the industrial frequency of 50 / 60 Hz.

[0025] The third object of the present invention is achieved by the following technical solution: A storage medium stores a program, and when the program is executed by a processor, the above-mentioned control method for the startup process of the grid-forming wind turbine is realized.

[0026] The fourth object of the present invention is achieved by the following technical solution: A computing device includes a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the above-mentioned control method for the startup process of the grid-forming wind turbine is realized.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] The present invention details the logic of the whole machine startup process, which can effectively solve the technical problems existing in the startup process of large-scale grid-forming wind turbines. And adopting the present invention does not require additional equipment, uses the unit itself as a synchronous power source, and can solve the problem of grid stability in large-scale wind power grid connection, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the architecture diagram of the grid-forming wind turbine.

[0030] Figure 2 This is the logic flow chart of the method of the present invention.

[0031] Figure 3 This is the architecture diagram of the system of the present invention. Detailed implementation manners

[0032] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the implementation manners of the present invention are not limited thereto.

[0033] Embodiment 1

[0034] This embodiment discloses a control method for the start-up process of a grid-forming wind turbine, which can be applied to large-scale offshore wind turbines. As Figure 1 shown, the main components of the unit include a gearbox, a permanent magnet generator, blades, an impeller, a tower, a main control system, a pitch system, and a full-power converter.

[0035] The main control system is the main body of the unit control system, which realizes important control and protection functions such as automatic start-up, automatic alignment, automatic speed regulation, automatic grid connection, automatic disconnection, automatic shutdown in case of failure, automatic cable unwinding, and automatic recording and monitoring. The normal working logic control of the wind turbine. It is used for fault diagnosis and protection of the wind turbine, data acquisition / statistics, and data interaction control with each system, and is mainly composed of a PLC and other acquisition devices.

[0036] The full-power converter is used to convert the current output by the generator of the unit into a current synchronized with the grid voltage frequency and phase, and realizes power conversion, power control, torque control, power factor adjustment, grid fault ride-through, self-fault diagnosis and protection. It is mainly composed of a converter controller, IGBTs, a grid-side filter unit, a DC bus capacitor, a machine-side circuit breaker, a grid-side circuit breaker, a machine-side rectifier, a grid-side inverter, and a braking circuit; the machine-side circuit breaker is located between the generator and the machine-side rectifier, and is opened or closed to separate and connect the generator and the full-power converter; the grid-side circuit breaker is located between the grid-side inverter and the step-up transformer, and is opened or closed to separate and connect the full-power converter and the step-up transformer.

[0037] The pitch system receives the pitch angle command issued by the main control system, and controls the pitch mechanism to rotate the blade relative to the plane to reach the position pitch angle required by the control. It realizes pitch adjustment, pitch angle acquisition, self-abnormality protection, self-fault diagnosis and protection; the pitch system is divided into an electric pitch and a hydraulic pitch; the electric pitch is mainly composed of a pitch controller, a pitch drive device, and a pitch reducer; the hydraulic pitch is mainly composed of a pitch controller, a storage tank, and a link drive mechanism; the pitch angle is the angle of the blade relative to the horizontal plane, which is obtained by internal calculation by the pitch system through a collection device, a rotary encoder, and the rotary encoder can be an incremental rotary encoder or an absolute rotary encoder.

[0038] As Figure 2 shown, the control method for the starting process of the grid-forming wind turbine disclosed in this embodiment includes the following steps:

[0039] 1) Standby state:

[0040] After the unit is powered on, it performs self-check. When there is no fault after the self-check, the start button is pressed. The main control system of the unit sends a request to close the machine-side circuit breaker to the full-power converter. The full-power converter executes the instruction to close the machine-side circuit breaker. After the machine-side circuit breaker is closed, it sends a signal indicating that the machine-side circuit breaker has been closed to the main control system. After receiving the signal indicating that the machine-side circuit breaker has been closed, the unit enters the starting state.

[0041] 2) Starting state:

[0042] The main control system sends an instruction to the pitch system to pitch the blades to the pitch angle Angle1 in the starting state. The machine-side rectifier of the full-power converter performs modulation and executes DC bus control, and determines whether the following conditions are met: whether the generator speed reaches the target value RPM1 in the speed-up state and exceeds the preset time, and whether the DC bus voltage reaches the set value U dc.ref and exceeds the preset time. If both conditions are met, the unit enters the speed-up state; otherwise, it remains in the starting state. The DC bus voltage is the voltage across the DC bus support capacitor of the full-power converter, which is obtained by internal calculation by the converter controller of the full-power converter. The generator speed is the electromagnetic speed of the generator obtained by the full-power converter based on the acquisition and calculation of the generator terminal voltage, and can also be obtained by the main control system based on the acquisition and calculation of the generator proximity switch.

[0043] 3) Speed-up state:

[0044] The main control system sends a pitch-to-minimum-position instruction to the pitch system to pitch the blades to the minimum blade pitch angle Angle2. The machine-side rectifier of the full-power converter performs modulation and determines whether the following conditions are met: whether the generator speed reaches the target value RPM2 in the requested grid-connected state and exceeds the preset time, and whether the detected grid-side voltage is greater than or equal to K × the rated grid-connected positive-sequence voltage (U), where the coefficient k is not greater than 1 and its value is determined according to the dynamic characteristics of the full-power converter, and the recommended value is 0.8. If both conditions are met, the unit enters the normal starting process in the grid-connected state; otherwise, it is necessary to further determine whether both the generator speed reaches the target value RPM2 in the requested grid-connected state and exceeds the preset time, and the detected grid-side voltage is less than K × the rated grid-connected positive-sequence voltage (U). If both are met, the unit enters the build-up voltage starting process in the grid-connected state. Subsequently, it is detected whether the electromagnetic speed reaches the target value RPM3 and exceeds the preset time. If it is met, the unit enters the grid-connected state; otherwise, the unit remains in the starting state.

[0045] 4) Grid-connected state:

[0046] The main control system sends synchronization commands, torque set values, and reactive power set values to the full-power converter. The main control system performs constant-speed control and sends pitch angle commands to the pitch system according to the control results of the original speed controller. After receiving the synchronization command during the normal startup process of the full-power converter, it executes the closing of its grid-side circuit breaker. After the closing is completed, it sends a closing completion command to the main control system. The grid side executes the virtual synchronous machine algorithm and performs modulation startup to operate according to the torque set value and reactive power set value of the main control system. After receiving the synchronization command during the voltage build-up startup process of the full-power converter, it sends a signal to enter the state of self-building voltage, internally generates the grid reference phase angle and voltage reference value, and performs modulation voltage build-up. Then it judges whether the grid-connected voltage reaches the set value, the grid-connected power exceeds 0 kW and exceeds the preset time. If satisfied, the full-power converter enters the AC SOURCE state; otherwise, it continues to wait. Among them, the AC SOURCE state means that the full-power converter controls the output voltage to be the rated value of the grid-connected voltage and controls the grid-connected frequency to be the industrial frequency of 50 / 60 Hz.

[0047] Embodiment 2

[0048] This embodiment discloses a control system for the startup process of a grid-forming wind turbine generator set, as Figure 3 shown. The system includes the following functional modules:

[0049] Standby module: After the unit is powered on, it performs self-check. When the start button is pressed in the fault-free state after the self-check is completed, it sends a request to close the machine-side circuit breaker to the full-power converter through the main control system of the unit. The full-power converter executes the machine-side circuit breaker closing command. After the machine-side circuit breaker completes the closing, it sends a signal indicating that the machine-side circuit breaker has completed the closing to the main control system. After receiving the signal indicating that the machine-side circuit breaker has completed the closing, the unit enters the startup state.

[0050] Startup module: It sends a command to the pitch system through the main control system to pitch the blades to the pitch angle Angle1 in the startup state. The machine-side rectifier of the full-power converter performs modulation and executes DC bus control, and judges whether the following conditions are met: whether the generator speed reaches the target value RPM1 in the speed-up state and exceeds the preset time, and whether the DC bus voltage reaches the set value U dc.ref and exceeds the preset time. If both conditions are met, the unit enters the speed-up state; otherwise, it remains in the startup state. The DC bus voltage is the voltage across the DC bus support capacitor of the full-power converter, which is obtained by internal calculation through the current converter controller of the full-power converter. The generator speed is the electromagnetic speed of the generator obtained by the full-power converter according to the voltage acquisition at the generator terminal, and can also be obtained by the main control system according to the generator proximity switch acquisition and calculation.

[0051] The speed-up module sends a pitch-changing command to the pitch system to change the pitch to the minimum pitch angle Angle2 through the main control system. The machine-side rectifier of the full-power converter is modulated to determine whether the following conditions are met: whether the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and whether the detected grid-side voltage is greater than or equal to K × the rated positive-sequence grid voltage (U), where the coefficient k is not greater than 1 and its value is determined according to the dynamic characteristics of the full-power converter, and the recommended value is 0.8. If both conditions are met, the unit enters the normal starting process of the grid-connected state; otherwise, it is necessary to further determine whether both the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and the detected grid-side voltage is less than K × the rated positive-sequence grid voltage (U). If both are met, the unit enters the voltage-building starting process of the grid-connected state. Subsequently, it is detected whether the electromagnetic speed reaches the target value RPM3 and exceeds the preset time. If it is met, the unit enters the grid-connected state; otherwise, the unit maintains the starting state.

[0052] The grid-connection module sends a synchronization command, a torque set value, and a reactive power set value to the full-power converter through the main control system. The main control system performs constant-speed control and sends a pitch angle command to the pitch system according to the control result of the original speed controller. After receiving the synchronization command during the normal starting process of the full-power converter, it closes its grid-side circuit breaker. After the closing is completed, it sends a command indicating the completion of closing to the main control system. The grid side executes the virtual synchronous machine algorithm and executes modulation to start running according to the torque set value and reactive power set value of the main control system. After receiving the synchronization command during the voltage-building starting process of the full-power converter, it issues a command to enter the state of self-building the voltage, internally generates the grid reference phase angle and voltage reference value, and executes modulation to build the voltage. Subsequently, it is determined whether the grid-connected voltage reaches the set value and the grid-connected power exceeds 0 kW and exceeds the preset time. If it is met, the full-power converter enters the AC SOURCE state; otherwise, it continues to wait. Among them, the AC SOURCE state means that the full-power converter controls the output voltage to be the rated grid-connected voltage and controls the grid-connected frequency to be the industrial frequency of 50 / 60 Hz.

[0053] Embodiment 3

[0054] This embodiment discloses a storage medium storing a program, which when executed by a processor, implements the control method for the starting process of the grid-forming wind turbine unit described in Embodiment 1.

[0055] The storage medium in this embodiment can be a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, and other media.

[0056] Embodiment 4

[0057] This embodiment discloses a computing device, including a processor and a memory for storing programs executable by the processor. When the processor executes the programs stored in the memory, it implements the control method for the start-up process of the network-forming wind turbine set described in Embodiment 1.

[0058] The computing device described in this embodiment may be a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with processor functions.

[0059] The above embodiments are preferred embodiments of the present invention. However, the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A control method for the starting process of a grid-forming wind turbine, characterized in that, It includes the following steps: 1) Standby state: After the unit is powered on, it performs self-check. When there is no fault after the self-check, press the start button. The main control system of the unit sends a request to close the machine-side circuit breaker to the full-power converter. The full-power converter executes the instruction to close the machine-side circuit breaker. After the machine-side circuit breaker completes the closing, it sends a signal indicating that the machine-side circuit breaker has completed the closing to the main control system. After receiving the signal that the machine-side circuit breaker has completed the closing, the unit enters the start state; 2) Start state: The main control system sends a command to the pitch system to pitch the blade to the pitch angle Angle1 in the starting state. The machine-side rectifier of the full-power converter performs modulation and executes DC bus control, and judges whether the following conditions are met: whether the generator speed reaches the target value RPM1 in the speed-up state and exceeds the preset time, and whether the DC bus voltage reaches the set value U dc.ref and exceeds the preset time. If both conditions are met, the unit enters the speed-up state; otherwise, it remains in the starting state 3) Speed-up state: The main control system sends a pitch-changing instruction to the pitch system to change the pitch to the minimum pitch angle Angle2. The machine-side rectifier of the full-power converter performs modulation and judges whether the following conditions are met: whether the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and whether the detected grid-side voltage is greater than or equal to K×the rated positive-sequence grid voltage, where the coefficient k is not greater than 1 and its value is determined according to the dynamic characteristics of the full-power converter. If both conditions are met, the unit enters the normal starting process of the grid-connected state. Otherwise, it is necessary to further judge whether both the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and the detected grid-side voltage is less than K×the rated positive-sequence grid voltage. If both are met, the unit enters the build-up voltage starting process of the grid-connected state. Subsequently, it is detected whether the electromagnetic speed reaches the target value RPM3 and exceeds the preset time. If it is met, the unit enters the grid-connected state. Otherwise, the unit maintains the start state; 4) Grid-connected state: The main control system sends a synchronization instruction, a torque set value, and a reactive power set value to the full-power converter. The main control system executes constant-speed control and sends a pitch angle instruction to the pitch system according to the control result of the original speed controller. After receiving the synchronization instruction during the normal starting process of the full-power converter, it executes the closing of its grid-side circuit breaker. After the closing is completed, it sends a completed closing instruction to the main control system. The grid side executes the virtual synchronous machine algorithm and executes modulation to start running at the torque set value and reactive power set value of the main control system. After receiving the synchronization instruction during the build-up voltage starting process of the full-power converter, it sends a signal to enter the state of self-building the voltage, internally generates the grid reference phase angle and voltage reference value, and executes modulation to build up the voltage. Subsequently, it is judged whether the grid-connected voltage reaches the set value and the grid-connected power exceeds 0 kW and exceeds the preset time. If it is met, the full-power converter enters the AC SOURCE state. Otherwise, it continues to wait.

2. The control method for the starting process of a grid-forming wind turbine according to claim 1, characterized in that: In step 2), the DC bus voltage is the voltage across the DC bus support capacitor of the full-power converter, which is obtained by internal calculation by the converter controller of the full-power converter; the generator speed is the generator electromagnetic speed obtained by the full-power converter according to the generator terminal voltage acquisition and calculation, and can also be obtained by the main control system according to the generator proximity switch acquisition and calculation.

3. The control method for the starting process of a grid-forming wind turbine according to claim 1, characterized in that: In step 4), the AC SOURCE state means that the full-power converter controls the output voltage to be the rated grid-connected voltage value and controls the grid-connected frequency to be the industrial frequency of 50 / 60 Hz.

4. A control system for the starting process of a grid-forming wind turbine, characterized in that, It includes: Standby module: After the unit is powered on, it performs self-check. When the start button is pressed in the fault-free state after self-check, it sends a request to close the machine-side circuit breaker to the full-power converter through the main control system of the unit. The full-power converter executes the instruction to close the machine-side circuit breaker. After the machine-side circuit breaker is closed, it feeds back a signal indicating that the machine-side circuit breaker is closed to the main control system. After receiving the signal that the machine-side circuit breaker is closed, the unit enters the start state; Start-up module, which sends instructions to the pitch system through the main control system to pitch the blades to the start-up state pitch angle Angle1. The machine-side rectifier of the full-power converter performs modulation and executes DC bus control, and determines whether the following conditions are met: whether the generator speed reaches the target value RPM1 of the speed-up state and exceeds the preset time, and whether the DC bus voltage reaches the set value U dc.ref and exceeds the preset time. If both conditions are met, the unit enters the speed-up state; otherwise, it remains in the start-up state Speed-up module: It sends a pitch-changing instruction to the pitch system to change the blades to the minimum pitch angle Angle2 through the main control system, and the machine-side rectifier of the full-power converter performs modulation. It judges whether the following conditions are met: whether the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and whether the detected grid-side voltage is greater than or equal to K × the rated positive-sequence grid voltage, where the coefficient k is not greater than 1 and its value is determined according to the dynamic characteristics of the full-power converter. If both conditions are met, the unit enters the normal start-up process of the grid-connected state. Otherwise, it needs to further judge whether both the generator speed reaches the target value RPM2 of the requested grid-connected state and exceeds the preset time, and the detected grid-side voltage is less than K × the rated positive-sequence grid voltage. If both are met, the unit enters the build-up voltage start-up process of the grid-connected state. Subsequently, it detects whether the electromagnetic speed reaches the target value RPM3 and exceeds the preset time. If it is met, the unit enters the grid-connected state. Otherwise, the unit maintains the start state; Grid-connection module: It sends a synchronization instruction, a torque set value, and a reactive power set value to the full-power converter through the main control system. The main control system performs constant-speed control and sends a pitch angle instruction to the pitch system according to the control result of the original speed controller; After receiving the synchronization instruction during the normal start-up process of the full-power converter, it executes the closing of its grid-side circuit breaker. After the closing is completed, it feeds back a closing instruction to the main control system. The grid side executes the virtual synchronous machine algorithm and executes modulation to start running at the torque set value and reactive power set value of the main control system; During the build-up voltage start-up process of the full-power converter, after receiving the synchronization instruction, it sends a signal to enter the state of self-constructing the voltage, internally generates the grid reference phase angle and voltage reference value, and executes modulation to build up the voltage. Subsequently, it judges whether the grid-connected voltage reaches the set value and the grid-connected power exceeds 0 kW and exceeds the preset time. If it is met, the full-power converter enters the AC SOURCE state. Otherwise, it continues to wait.

5. The control system for the starting process of a grid-forming wind turbine according to claim 4, characterized in that: In the start-up module, the DC bus voltage is the voltage across the DC bus support capacitor of the full-power converter, which is obtained by internal calculation through the current converter controller of the full-power converter; The generator speed is the electromagnetic speed of the generator obtained by the full-power converter according to the voltage acquisition at the generator terminal, and can also be obtained by the main control system according to the generator proximity switch acquisition and calculation.

6. The control system for the starting process of a grid-forming wind turbine according to claim 4, characterized in that: In the grid-connection module, the AC SOURCE state means that the full-power converter controls the output voltage to be the rated grid-connected voltage and controls the grid-connected frequency to be the industrial frequency 50 / 60 Hz.

7. A storage medium storing a program, characterized in that, When the program is executed by the processor, it realizes the grid-forming type wind turbine start-up process control method described in any one of claims 1 to 3.

8. A computing device including a processor and a memory for storing a program executable by the processor, characterized in that, When the processor executes the program stored in the memory, it implements the grid-forming wind turbine startup process control method described in any one of claims 1 to 3.

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