Wind turbine generator black start device and wind turbine generator black start method

Abstract

The invention discloses a wind turbine generator black start device and a wind turbine generator black start method. The wind turbine generator black start device comprises a power supply module, a wind turbine generator, a power supply monitoring unit and a power supply control unit, the wind turbine generator is in on-off connection with a power grid through a direct current bus, the power supply module is in on-off connection with the direct current bus, and the power supply monitoring unit is connected with the power supply module and the wind turbine generator and monitors the power supply module and the wind turbine generator. The power supply control unit is connected with the power supply module and a pre-charging loop of the wind turbine generator set, controls the connection and disconnection of the power supply module and the pre-charging loop with the DC bus, and is independently powered by the power supply module. The condition that the wind turbine generator fails to supply power to the control unit in the black start process can be avoided, controllable execution of black start is guaranteed, conversion control between the wind turbine generator and the power module is achieved, and black start is completed.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a black start device and method for wind turbine generators. Background Technology

[0002] Currently, existing wind turbines are mainly connected to the grid. Frequent grid connection and disconnection can cause certain impacts on the power grid, which cannot effectively support voltage stability and can also cause or exacerbate grid fluctuations, especially for weak grids, rural grids and microgrid systems. At the same time, if wind turbines are in a low energy output condition for a long time, the power grid will not be able to replenish energy for a long time, thus affecting the stable operation of the power grid and load.

[0003] Current wind turbine technologies are primarily based on grid-connected operation, largely neglecting off-grid and grid outage scenarios. However, with the development of the wind power industry, wind turbines must adapt to large-scale grids as well as small-scale grids, rural grids, and microgrids. This diversity in grids necessitates that wind turbines possess the capability for off-grid or islanded operation. To address this, existing technologies have proposed black-start technology for wind turbines, controlling their automatic start-up.

[0004] However, current black-start methods for wind turbines typically use a programmable logic controller (PLC) to control the turbine. However, the PLC is usually powered by the wind turbine itself. When a wind turbine malfunctions, the inability to supply power can prevent a black start. Summary of the Invention

[0005] Therefore, it is necessary to provide a black start device and method for wind turbines to address the technical problem of easy failure of black start in existing wind turbine technology.

[0006] This invention provides a black start device for wind turbine generators, comprising: a power module, a wind turbine generator, a power monitoring unit, and a power control unit. The wind turbine generator is connected to the power grid via a DC bus, and the power module is connected to the DC bus. The power monitoring unit is connected to both the power module and the wind turbine generator to monitor them. The power control unit is connected to the pre-charging circuits of both the power module and the wind turbine generator to control the connection and disconnection of the power module, the pre-charging circuits, and the DC bus. The power control unit is independently powered by the power module.

[0007] Furthermore, the pre-charging circuit includes a current-limiting resistor and a rectifier circuit. One end of the current-limiting resistor is connected to the rectifier circuit, and the other end is connected to the DC bus through a pre-charging circuit contactor. The rectifier circuit is connected to the wind turbine generator of the wind turbine unit.

[0008] Furthermore, the power module includes: an energy storage device management system, an energy storage device, an inverter, and a step-up transformer. One end of the step-up transformer is connected to the DC bus via a power module contactor, and the other end is connected to the inverter and the energy storage device in sequence. The energy storage device management system is connected to the energy storage device.

[0009] Furthermore, the inverter includes: an AC switch, an AC / DC filter, an inverter circuit, and a DC switch. One end of the inverter circuit is connected to the energy storage device through the DC switch, and the other end is connected to the step-up transformer in sequence through the AC / DC filter and the AC switch.

[0010] This invention provides a method for black-starting a wind turbine as described above, comprising: The power monitoring unit monitors the power supply of the wind turbine. When the power monitoring unit determines that the power monitoring results meet the black start conditions, the power control unit controls the power module to connect with the pre-charge circuit. The power control unit controls the power module to charge the DC bus; When the DC bus voltage reaches the preset voltage threshold, the power control unit closes the main contactor of the wind turbine and disconnects the pre-charge circuit. After the DC bus stabilizes, the black start is complete.

[0011] Furthermore, the power control unit controls the power module to charge the DC bus, including: The power control unit sends a command to the power module to control the power module to charge the DC bus in constant current mode.

[0012] Furthermore, after the power control unit closes the main contactor of the wind turbine and disconnects the pre-charging circuit, it also includes: the power module cancels the constant current charging mode and switches to centralized coordination control mode.

[0013] Furthermore, it also includes: During the black start process, the power monitoring unit collects and processes the operating information of the power module, converter, and wind turbine in real time; The power monitoring unit determines whether a fault has occurred based on the operating information of the power module, converter, and wind turbine. When a fault occurs, the corresponding fault response strategy is executed.

[0014] Furthermore, the execution of the corresponding fault response strategy includes: Determine the priority of the fault; Based on the priority of the fault, the corresponding fault response strategy is executed.

[0015] Furthermore, the priority includes a first priority, a second priority, and a third priority, and the execution of the corresponding fault response strategy based on the fault priority includes: If the fault has the highest priority, the trip will automatically terminate. If the priority of the fault is the second priority, then the system enters a power-limited operation state. If the priority of the fault is the third priority, a fault alarm will be issued.

[0016] This invention adopts a layered design. The power monitoring unit monitors the power supply of the wind turbine to determine whether a black start is required. The black start operation is then performed by an independently powered power control unit. Since the power control unit is independently powered by the power module, it avoids the situation where the wind turbine fails during the black start process and cannot supply power to the control unit, thus ensuring the controllable execution of the black start and realizing the switching control between the wind turbine and the power module to complete the black start. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a black start device for a wind turbine according to an embodiment of the present invention; Figure 2 This is a circuit diagram of a black start device for a wind turbine according to an embodiment of the present invention; Figure 3 This is a communication schematic diagram according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a pre-charging circuit according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a power module according to an embodiment of the present invention; Figure 6 This is a schematic diagram of an inverter according to an embodiment of the present invention; Figure 7 This is a flowchart illustrating a black start method for a wind turbine generator set 2 according to an embodiment of the present invention. Figure 8 This is a flowchart illustrating a black start method for a wind turbine generator set 2 according to another embodiment of the present invention. Figure 9 This is a schematic diagram of state detection as an example of the present invention; Figure 10 This is a schematic diagram of the black start control process of the preferred embodiment of the present invention.

[0018] Marker description 1. Power module; 11. Energy storage device management system; 12. Energy storage device; 13. Inverter; 131. AC switch; 132. AC / DC filter; 133. Inverter circuit; 134. DC switch; 14. Step-up transformer; 15. Power module contactor; 2. Wind turbine; 20. Switch; 21. Pre-charge circuit; 211. Pre-charge circuit contactor; 212. Current limiting resistor; 213. Rectifier circuit; 22. Wind turbine generator; 23. DC side; 24. AC side; 201. Wind turbine control system; 202. Energy conversion module; 3. Power monitoring unit; 4. Power control unit; 5. DC bus; 6. Power grid; 911. High-speed ADC sampling circuit; 912. Field programmable gate array. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0020] This patent applies to both single power generation modules and combinations of multiple power generation modules.

[0021] like Figure 1 and Figure 2 The diagram shows a black start device for a wind turbine according to an embodiment of the present invention, comprising: a power module 1, a wind turbine 2, a power monitoring unit 3, and a power control unit 4. The wind turbine 2 is connected to the power grid 6 via a DC bus 5, and the power module 1 is connected to the DC bus 5. The power monitoring unit 3 is connected to both the power module 1 and the wind turbine 2 to monitor them. The power control unit 4 is connected to the pre-charging circuit 21 of both the power module 1 and the wind turbine 2 to control the connection and disconnection of the power module 1 and the pre-charging circuit 21 with the DC bus 5. The power control unit 4 is independently powered by the power module 1.

[0022] Specifically, the main hardware implementation device of the present invention, a black start device for a wind turbine, includes: a power module 1, a wind turbine 2, a power monitoring unit 3, and a power control unit 4.

[0023] The power module 1 is mainly used for startup power supply. The power monitoring unit 3 and the power control unit 4 are independently controlled, primarily based on power monitoring results and the status of the wind turbine. The power control unit 4 is a separate control module that can be placed in the converter or main control cabinet, while the power monitoring unit 3 is a separate functional unit placed in the main control cabinet. The wind turbine 2 is mainly used for wind power generation.

[0024] In some embodiments, the wind turbine 2 includes a wind turbine control system 201 and an energy conversion module 202. The wind turbine control system 201 is connected to the energy conversion module 202, and the energy conversion module 202 generates wind power under the control of the wind turbine control system 201. The power monitoring unit 3 is connected to the wind turbine control system 201 to monitor the status of the wind turbine.

[0025] In some embodiments, a communication module is also included for information exchange between the various modules.

[0026] like Figure 3 The diagram shown is a communication schematic of an embodiment of the present invention. The entire communication control unit mainly includes a Canopen communication unit, a TCP / IP communication unit, and a Modbus communication unit, which mainly realizes information interaction and coordinated control between various modules.

[0027] Among them, power module 1 is connected to the AC side of the wind turbine. During black start, it charges the DC bus through the pre-charge circuit of the converter. It can also be used as an auxiliary power supply system for the wind turbine in emergency conditions.

[0028] like Figure 2 The diagram shows a circuit schematic of a black start device for a wind turbine according to an embodiment of the present invention. The power module 1 is connected to the DC bus 5 via a power module contactor 15. The connection between the power module 1 and the DC bus 5 is controlled by opening and closing the power module contactor 15. The wind turbine 2 is connected to the power grid 6 via the DC bus 5, and the connection between the wind turbine 2 and the power grid 6 is controlled by a switch 20. The energy conversion module 202 of the wind turbine 2 includes a pre-charging circuit 21, a wind turbine generator 22, a DC side 23, and an AC side 24. One end of the pre-charging circuit 21 is connected to the wind turbine generator 22, and the other end is connected to the DC bus 5 via a pre-charging circuit contactor 211, thus controlling the connection between the pre-charging circuit 21 and the DC bus 5.

[0029] In one embodiment, the pre-charging circuit 21 includes a current-limiting resistor 212 and a rectifier circuit 213. One end of the current-limiting resistor 212 is connected to the rectifier circuit 213, and the other end is connected to the DC bus 5 through a pre-charging circuit contactor 211. The rectifier circuit 213 is connected to the wind turbine generator 22 of the wind turbine generator set 2.

[0030] Specifically, such as Figure 4 The diagram shows a pre-charging circuit according to an embodiment of the present invention. The pre-charging circuit 21 is a crucial component in the normal startup process of the wind turbine, aiming to safely and controllably charge the DC bus of the wind turbine using grid power, enabling the DC bus to reach the initial voltage required for startup. The pre-charging circuit 21 comprises a current-limiting resistor 212, a fuse, and a rectifier circuit 213. One end of the current-limiting resistor 212 is connected to the rectifier circuit 213, and the other end is connected to the DC bus 5 via a pre-charging circuit contactor 211. The rectifier circuit 213 is connected to the wind turbine generator 22 via the DC side 23 of the wind turbine 2. The pre-charging circuit contactor 211 is opened or closed under the control of the power control unit 4. In black-start mode, the wind turbine is connected to the power module 1 via the pre-charging circuit 21, and the electrical energy from the energy storage device of the power module 1 charges the DC side of the wind turbine.

[0031] In one embodiment, the power module 1 includes: an energy storage device management system 11, an energy storage device 12, an inverter 13, and a step-up transformer 14. One end of the step-up transformer 14 is connected to the DC bus 5 through a power module contactor 15, and the other end is connected to the inverter 13 and the energy storage device 12 in sequence. The energy storage device management system 11 is connected to the energy storage device 12.

[0032] Specifically, such as Figure 5 The diagram shows a power module according to an embodiment of the present invention. The power module 1 includes an energy storage management system 11, an energy storage device 12, an inverter 13, and a step-up transformer 14. The energy storage management system 11 is preferably a battery management system (BMS). The energy storage device 12 is preferably a battery (lithium iron phosphate or flow battery). The inverter 13 is preferably a power conversion system (PCS) inverter. One end of the step-up transformer 14 is connected to the DC bus 5 via a power module contactor 15, which is opened or closed under the control of the power control unit 4.

[0033] Power module 1 has functions such as battery charging / discharging, monitoring battery status, and data communication. It can also receive dispatch commands to perform peak shaving and valley filling, improve grid stability, and promote the consumption of new energy sources. The power module adopts a containerized modular design and is coupled to the wind turbine on the AC1140V / 35kV side, allowing it to be transported to different locations within the wind farm for flexible configuration.

[0034] In one embodiment, the inverter 13 includes an AC switch 131, an AC / DC filter 132, an inverter circuit 133, and a DC switch 134. One end of the inverter circuit 133 is connected to the energy storage device 12 through the DC switch 134, and the other end is connected to the step-up transformer 14 through the AC / DC filter 132 and the AC switch 131 in sequence.

[0035] like Figure 6 The diagram shows an inverter according to an embodiment of the present invention. The inverter serves as a power interface between the DC battery and the AC grid, converting energy from the battery to the wind turbine during black start. The inverter 13 consists of an AC switch 131, an AC / DC filter 132, an inverter circuit 133, and a DC switch 134. The AC / DC filter 132 stabilizes the DC voltage and filters out high-order harmonics of the AC circuit. The inverter circuit 133 employs a three-phase inverter topology and fully controlled components, enabling the PCS to have bidirectional converter functionality, suitable for scenarios where the power module frequently charges and discharges and has high power quality requirements.

[0036] This invention adopts a layered design. The power monitoring unit monitors the power supply of the wind turbine to determine whether a black start is required. The black start operation is then performed by an independently powered power control unit. Since the power control unit is independently powered by the power module, it avoids the situation where the wind turbine fails during the black start process and cannot supply power to the control unit, thus ensuring the controllable execution of the black start and realizing the switching control between the wind turbine and the power module to complete the black start.

[0037] like Figure 7 The diagram shown is a flowchart of a black start method for a wind turbine generator set 2 according to an embodiment of the present invention, including: Step S701: The power monitoring unit 3 monitors the power supply of the wind turbine 2. In step S702, when the power monitoring unit 3 determines that the power monitoring result meets the black start condition, the power control unit 4 controls the power module 1 to connect with the pre-charge circuit 21. In step S703, the power control unit 4 controls the power module 1 to charge the DC bus 5; Step S704: When the voltage of the DC bus 5 reaches the preset voltage threshold, the power control unit 4 closes the main contactor of the wind turbine 2 and disconnects the pre-charging circuit 21. Step S705: After the DC bus 5 stabilizes, the black start is completed.

[0038] Specifically, this invention can be applied to electronic devices with processing capabilities.

[0039] First, step S701 is executed, where the power monitoring unit 3 monitors the power supply of the wind turbine 2.

[0040] Specifically, the black start of wind turbine 2 requires coordinated control of power module 1, wind power converter, and wind power main control PLC based on the power supply status. The success of the black start places extremely high demands on communication efficiency, status synchronization, and control coordination. The collaborative control system of the black start device of wind turbine 2 achieves multi-timescale and multi-objective coordination through a layered architecture, which is divided into a centralized coordination layer, a local control layer, and an equipment execution layer.

[0041] The centralized coordination layer is executed by the power monitoring unit 3. It adjusts the operating status of the turbines according to the production needs of the wind farm, performs turbine start-up and shutdown, and optimizes wind energy capture efficiency; it monitors the turbine and battery status and grid parameters in real time, formulates energy storage charging and discharging plans, and provides fault protection functions for the entire system, while also monitoring the power supply of the wind turbine 2.

[0042] Then, step S702 is executed. When the power monitoring unit 3 determines that the power monitoring result meets the black start condition, the power control unit 4 controls the power module 1 to connect with the pre-charge circuit 21.

[0043] Specifically, the local control layer is executed by the power control unit 4. When the power monitoring unit 3 determines that the power monitoring results meet the black start conditions, the power control unit 4 begins to execute the black start. First, it closes the contactor between the pre-charge circuit 21 and the power module 1 and the power grid, thus connecting the power module 1 and the pre-charge circuit 21. The power control unit 4 is equipped with an uninterruptible power supply (UPS) for independent power supply.

[0044] Then, step S703 is executed, whereby the power control unit 4 controls the power module 1 to charge the DC bus 5.

[0045] Specifically, power module 1 switches to local control and charges the converter DC bus 5 according to the instructions of power control unit 4.

[0046] The device execution layer, executed by power module 1, receives instructions from the centralized coordination layer and the local control layer, uploads battery status information, balances the deep charge / discharge and cycle life of the energy storage battery, and reduces the total life cycle cost.

[0047] Then, step S704 is executed. When the voltage of the DC bus 5 reaches the preset voltage threshold, the power control unit 4 closes the main contactor of the wind turbine 2 and disconnects the pre-charging circuit 21.

[0048] Specifically, when the DC bus voltage reaches 90% of the rated voltage, the converter closes the main contactor of the wind turbine generator 2 and disconnects the pre-charge circuit 21. Here, disconnecting the pre-charge circuit 21 means disconnecting the pre-charge circuit 21 from the power module 1, at which time the power module 1 is not connected to the DC bus.

[0049] Finally, step S705 is executed, and the black start is completed after the DC bus 5 stabilizes.

[0050] Specifically, after the DC bus 5 stabilizes, the power control unit 4 unlocks the grid-side and generator-side converters in sequence to adjust the output power after black start according to the generator speed.

[0051] This invention adopts a layered design. The power monitoring unit 3 monitors the power supply of the wind turbine 2 to determine whether a black start is required. The independently powered power control unit 4 performs the black start operation. Since the power control unit 4 is independently powered by the power module 1, it can avoid the situation where the wind turbine 2 fails and cannot supply power to the control unit during the black start process, thus ensuring the controllable execution of the black start and realizing the switching control between the wind turbine 2 and the power module 1 to complete the black start.

[0052] like Figure 8 The diagram shown is a flowchart of a black start method for a wind turbine generator set 2 according to another embodiment of the present invention, including: Step S801: The power monitoring unit 3 monitors the power supply of the wind turbine 2.

[0053] In step S802, when the power monitoring unit 3 determines that the power monitoring result meets the black start condition, the power control unit 4 controls the power module 1 to connect with the pre-charging circuit 21. The power control unit 4 is independently powered by the power module 1.

[0054] In step S803, the power control unit 4 sends a command to the power module 1 to control the power module 1 to charge the DC bus 5 in constant current mode. During the black start process, the power monitoring unit 3 collects and processes the operating information of the power module 1, converter, and wind turbine 2 in real time. The power monitoring unit 3 determines whether a fault has occurred based on the operating information of the power module 1, the converter, and the wind turbine 2. When a fault occurs, the corresponding fault response strategy is executed.

[0055] In step S804, when the voltage of the DC bus 5 reaches the preset voltage threshold, the power control unit 4 closes the main contactor of the wind turbine 2 and disconnects the pre-charging circuit 21.

[0056] Step S805: Power module 1 switches from constant current charging mode to centralized coordination control mode.

[0057] Step S806: After the DC bus 5 stabilizes, the black start is completed.

[0058] Specifically, step S801 is executed first, in which the power monitoring unit 3 monitors the power supply of the wind turbine 2.

[0059] Specifically, this is performed by the power monitoring unit 3. It adjusts the operating status of the turbines according to the production needs of the wind farm, performs turbine start-up and shutdown, and optimizes wind energy capture efficiency; it monitors the turbine and battery status and grid parameters in real time, formulates energy storage charging and discharging plans, and provides fault protection functions for the entire system, thus monitoring the power supply of the wind turbine 2.

[0060] Then, step S802 is executed. When the power monitoring unit 3 determines that the power monitoring result meets the black start condition, the power control unit 4 controls the power module 1 to connect with the pre-charge circuit 21. The power control unit 4 is independently powered by the power module 1.

[0061] Specifically, this is executed by the power control unit 4. When the power monitoring unit 3 determines that the power monitoring results meet the black start conditions, the power control unit 4 begins to execute the black start. First, it closes the contactor between the pre-charge circuit 21 and the power module 1 and the power grid, thus connecting the power module 1 and the pre-charge circuit 21.

[0062] Then, step S803 is executed, where the power control unit 4 sends a command to the power module 1 to control the power module 1 to charge the DC bus 5 in constant current mode. During the black start process, the power monitoring unit 3 collects and processes the operating information of the power module 1, converter, and wind turbine 2 in real time. The power monitoring unit 3 determines whether a fault has occurred based on the operating information of the power module 1, the converter, and the wind turbine 2. When a fault occurs, the corresponding fault response strategy is executed.

[0063] Specifically, power module 1 switches to local control and charges the DC bus 5 of the converter in constant current mode according to the converter command.

[0064] Meanwhile, during the black start process, this device adopts a real-time fault information sharing safety protection mechanism. The power monitoring unit 3, as the protection center, collects and processes the operating information of the power module 1, converter, and wind turbine 2 in real time.

[0065] In one embodiment, executing the corresponding fault response strategy includes: Determine the priority of the fault; Based on the priority of the fault, the corresponding fault response strategy is executed.

[0066] Specifically, the security protection mechanism adopts a priority-based fault response strategy, executing the corresponding fault response strategy according to the priority of the fault.

[0067] In one embodiment, the priority includes a first priority, a second priority, and a third priority, and the execution of a corresponding fault response strategy based on the fault priority includes: If the fault has the highest priority, the trip will automatically terminate. If the priority of the fault is the second priority, then the system enters a power-limited operation state. If the priority of the fault is the third priority, a fault alarm will be issued.

[0068] Specifically, the safety protection mechanism adopts a three-level fault response strategy. Level 1 faults require rapid local action; when the equipment detects a fatal fault such as an IGBT short circuit, control board failure, drive circuit failure, or grid-connected circuit breaker failure, it immediately trips autonomously. Autonomous tripping means tripping actively without external control. Level 2 faults require system cascading interlocking; when the system detects a serious fault such as module hardware overcurrent, abnormal motor speed, or stator voltage over-limit, the system enters a power-limited operation state. Level 3 faults are those other than Levels 1 and 2, such as DC bus 5 pre-charge timeout or cooler overheating, requiring system fault alarms.

[0069] like Figure 9 As shown, the status detection function analyzes the rising slope and ripple characteristics of the charging current waveform in real time through the high-speed ADC sampling circuit 911 in the converter and power module 1. The field-programmable gate array (FPGA) 912 calculates the actual charging energy by comparing it with a preset RC model, verifies the health status of capacitors, identifies abnormalities such as contactor contact resistance, and sends the data to the power monitoring unit 3. Simultaneously, during status detection, a constant drive voltage is injected to test parameters such as the on-state voltage drop and turn-on / off delay of the power conversion unit, identifying degraded cells and predicting aging risks.

[0070] Then, step S804 is executed. When the voltage of the DC bus 5 reaches the preset voltage threshold, the power control unit 4 closes the main contactor of the wind turbine 2 and disconnects the pre-charge circuit 21.

[0071] Specifically, when the DC bus 5 voltage reaches 90% of the rated voltage, the converter closes the main contactor of the wind turbine 2 and disconnects the pre-charge circuit 21.

[0072] Then, step S805 is executed, and power module 1 is deactivated from constant current charging mode and switched to centralized coordination control mode.

[0073] Specifically, power module 1 switches from constant current charging mode to centralized coordination control. Centralized coordination control mode refers to responding to centralized control commands from the site.

[0074] Finally, step S806 is executed, and the black start is completed after the DC bus 5 stabilizes.

[0075] Specifically, after the DC bus 5 stabilizes, the power control unit 4 unlocks the grid-side and generator-side converters in sequence to adjust the output power after black start according to the generator speed.

[0076] This embodiment monitors the status of the power module 1 of the wind turbine 2 and performs hierarchical coordinated control of the power module 1, power control unit 4, and power monitoring unit 3 to achieve the switching control between the wind turbine 2 and the external power source and complete the black start. Simultaneously, this embodiment controls the power module to charge the DC bus in constant current mode, ensuring stable startup and operation of the converter. Finally, this embodiment utilizes a hierarchical protection mechanism with real-time fault information sharing and status detection and diagnostic functions to promptly detect and warn of module faults, avoiding black start failure due to pre-charging failure.

[0077] like Figure 10 The diagram shown is a schematic representation of the black start control flow of the preferred embodiment of the present invention, including: Step S1001: Start the power supply unit; In step S1002, the power monitoring and control unit monitors the status of the wind turbine and the power module, and the wind turbine control system detects the status of the wind turbine. Step S1003: The wind turbine control system determines the wind turbine start-up conditions; Step S1004: Determine the grid connection conditions for wind turbine units; Step S1005: The wind turbine control system performs phase-locked control; In step S1006, the wind turbine energy conversion unit performs energy conversion and feeds back the conversion command to the control system, and the wind turbine outputs the converted energy. Step S1007: The power monitoring and control unit monitors the status of the wind turbine and power module; In step S1008, the power monitoring and control unit performs power conversion, completes black start, and returns to step S1002.

[0078] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0079] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A black start device for wind turbine generators, characterized in that, include: Power module (1), wind turbine (2), power monitoring unit (3) and power control unit (4). The wind turbine (2) is connected to the power grid (6) via a DC bus (5), and the power supply module (1) is connected to the DC bus (5). The power monitoring unit (3) is connected to the power module (1) and the wind turbine (2) respectively, and monitors the power module (1) and the wind turbine (2). The power control unit (4) is connected to the power module (1) and the pre-charging circuit (21) of the wind turbine (2) respectively, and controls the connection and disconnection of the power module (1) and the pre-charging circuit (21) with the DC bus (5). The power control unit (4) is independently powered by the power module (1).

2. The wind turbine black start device according to claim 1, characterized in that, The pre-charging circuit (21) includes a current-limiting resistor (212) and a rectifier circuit (213). One end of the current-limiting resistor (212) is connected to the rectifier circuit (213), and the other end is connected to the DC bus (5) through the pre-charging circuit contactor (211). The rectifier circuit (213) is connected to the wind turbine generator (22) of the wind turbine generator set (2).

3. The wind turbine black start device according to claim 1, characterized in that, The power module (1) includes: an energy storage device management system (11), an energy storage device (12), an inverter (13), and a step-up transformer (14). One end of the step-up transformer (14) is connected to the DC bus (5) through a power module contactor (15), and the other end is connected to the inverter (13) and the energy storage device (12) in sequence. The energy storage device management system (11) is connected to the energy storage device (12).

4. The wind turbine black start device according to claim 3, characterized in that, The inverter (13) includes an AC switch (131), an AC / DC filter (132), an inverter circuit (133), and a DC switch (134). One end of the inverter circuit (133) is connected to the energy storage device (12) through the DC switch (134), and the other end is connected to the step-up transformer (14) in sequence through the AC / DC filter (132) and the AC switch (131).

5. A method for black-starting a wind turbine generator using a black-start device as described in any one of claims 1 to 4, characterized in that, include: The power monitoring unit (3) monitors the power supply of the wind turbine (2); When the power monitoring unit (3) determines that the power monitoring result meets the black start condition, the power control unit (4) controls the power module (1) to connect with the pre-charge circuit (21); The power control unit (4) controls the power module (1) to charge the DC bus (5); When the voltage of the DC bus (5) reaches the preset voltage threshold, the power control unit (4) closes the main contactor of the wind turbine (2) and disconnects the pre-charging circuit (21). After the DC bus (5) stabilizes, the black start is completed.

6. The wind turbine black start method of the wind turbine black start device according to claim 5, characterized in that, The power control unit (4) controls the power module (1) to charge the DC bus (5), including: The power control unit (4) sends a command to the power module (1) to control the power module (1) to charge the DC bus (5) in constant current mode.

7. The wind turbine black start method of the wind turbine black start device according to claim 6, characterized in that, After the power control unit (4) closes the main contactor of the wind turbine (2) and disconnects the pre-charging circuit (21), it also includes: the power module (1) releases the constant current charging mode and switches to the centralized coordination control mode.

8. The wind turbine black start method of the wind turbine black start device according to claim 5, characterized in that, Also includes: During the black start process, the power monitoring unit (3) collects and processes the operating information of the power module, converter and wind turbine in real time; The power monitoring unit (3) determines whether a fault has occurred based on the operating information of the power module, converter, and wind turbine. When a fault occurs, the corresponding fault response strategy is executed.

9. The wind turbine black start method of the wind turbine black start device according to claim 8, characterized in that, The execution of the corresponding fault response strategy includes: Determine the priority of the fault; Based on the priority of the fault, the corresponding fault response strategy is executed.

10. The wind turbine black-start method of the wind turbine black-start device according to claim 9, characterized in that, The priorities include a first priority, a second priority, and a third priority. The execution of the corresponding fault response strategy based on the fault's priority includes: If the fault has the highest priority, the trip will automatically terminate. If the priority of the fault is the second priority, then the system enters a power-limited operation state. If the priority of the fault is the third priority, a fault alarm will be issued.

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