Variable pitch backup power supply system of wind turbine generator and wind turbine generator

Abstract

The invention provides a variable pitch backup power supply system of a wind turbine generator and the wind turbine generator. A super capacitor assembly and a fault energy release assembly are electrically connected and in signal communication with a charger assembly through a primary power cable and a secondary signal cable; the super capacitor assembly is formed by connecting a plurality of super capacitors in series, each capacitor in the module is provided with a voltage-sharing circuit, and the super capacitor assembly is integrated with an over-temperature alarm loop and an over-voltage alarm loop; the charger assembly primary loop converts external input alternating current into direct current meeting the charging requirement of the super-capacitor assembly, and the charger assembly secondary loop is integrated with a single-chip microcomputer, collects system parameters and calculates the state of the super-capacitor. A high-power resistor of the fault energy release assembly is connected with the super capacitor assembly through a circuit breaker and a contactor in sequence to form an energy release loop; the charger assembly controls on-off of a contactor coil through the digital quantity output signal so as to control opening and closing of an energy release loop. The whole system can instantly provide sufficient electric energy for the variable pitch driver.

Description

Technical Field

[0001] This invention belongs to the field of new energy power generation and relates to wind turbine pitch system technology, specifically a wind turbine pitch backup power system and a wind turbine. Background Technology

[0002] The backup power supply for the wind turbine pitch drive is a core emergency backup device ensuring the safe operation of the unit. Specifically, it refers to an independent power supply unit that can immediately provide stable and continuous power to the pitch drive when the main power supply (usually from the nacelle generator or the grid) fails, ensuring the normal operation of the pitch actuator (pitch motor or hydraulic actuator). Its core function is to mitigate the risk of pitch drive failure due to main power failure and provide critical energy support for the wind turbine to enter a safe shutdown state.

[0003] In the prior art, a typical backup power system for a wind turbine generator, such as the patent application with publication number CN219611404U, mainly includes an energy storage battery, a DC / DC converter, a DC / AC converter, and a pre-charging unit. This scheme utilizes the function of the wind turbine generator's own converter. When the main power supply is interrupted, the energy storage battery establishes voltage for the DC bus of the converter through the DC / DC converter, and supplies power to the first load (such as electrical equipment) in the wind turbine through the DC / AC converter. At the same time, it can supply power to the second load (such as controllers and sensors) through the adapter power supply.

[0004] However, this existing technical solution mainly focuses on extending the overall operating time of the backup power supply and expanding the power supply targets. Its core energy storage unit still uses traditional batteries. Therefore, it still inherits a series of inherent defects of batteries. Specifically, this solution has the following objective shortcomings: 1. Its response speed is limited by multi-stage energy conversion (DC / DC, DC / AC) and complex switching logic (involving the interlocking and control of multiple switches), making it difficult to achieve the millisecond-level power supply switching required for pitch drive after the main power supply of the wind turbine fails, posing a risk of operation interruption. 2. In the harsh high-altitude and low-temperature environments commonly encountered by wind turbines, the energy storage batteries used suffer from severe capacity decay, increased internal resistance, and unstable discharge performance, making it difficult to guarantee that the pitch actuator can still obtain sufficient and stable instantaneous power at extreme low temperatures. Summary of the Invention

[0005] To address the issues of response delay, poor weather resistance, and weak anti-interference capabilities in existing wind turbine pitch backup power supplies, this invention provides a wind turbine pitch backup power system and wind turbine. By integrating supercapacitor components, charger components, and fault discharge components, it can instantly provide sufficient power to the pitch drive. In the high-altitude and low-temperature environments commonly encountered by wind turbines, the capacity attenuation is small, the discharge performance is stable, and the charging and discharging process is a physical reaction, making the safety performance more reliable. This improves the emergency power supply reliability of the pitch system and the overall operational safety of the wind turbine.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows: A wind turbine pitch backup power system includes a supercapacitor assembly, a charger assembly, and a fault discharge assembly; the supercapacitor assembly and the fault discharge assembly are electrically connected and communicate with the charger assembly via primary power cables and secondary signal cables. The supercapacitor assembly consists of multiple supercapacitors connected in series. Each capacitor in the module is equipped with a voltage equalization circuit. The supercapacitor assembly also integrates an over-temperature alarm circuit and an over-voltage alarm circuit to output corresponding digital alarm signals to the charger assembly. The charger assembly includes a primary circuit and a secondary circuit. The primary circuit is used to convert external input AC power into DC power that meets the charging requirements of the supercapacitor assembly. The secondary circuit integrates a microcontroller for collecting system parameters and calculating the supercapacitor status. The fault energy dissipation component includes a high-power resistor, a circuit breaker, and a contactor; the high-power resistor is connected to the supercapacitor component in sequence through the circuit breaker and the contactor to form an energy dissipation circuit; and the charger component controls the contactor coil to open and close through a digital output signal to control the opening and closing of the energy dissipation circuit.

[0007] Furthermore, the supercapacitor assembly integrates an over-temperature alarm circuit and an over-voltage alarm circuit. Specifically, the supercapacitor assembly module has multiple external functional interface circuits, including at least: The temperature status feedback loop uses a temperature control switch to provide feedback on whether the temperature exceeds the threshold. The temperature sampling loop collects and transmits the real-time temperature of the supercapacitor component through the temperature sensor transmission module; The voltage status feedback loop uses a varistor to provide feedback on whether the voltage exceeds a threshold. The voltage sampling circuit outputs the actual voltage of the supercapacitor component after proportional attenuation through a voltage divider circuit.

[0008] Furthermore, the primary circuit of the charger assembly includes a rectifier board and a power board. The rectifier board converts the input three-phase AC power into DC power, and the power board converts the DC power into DC power that meets the charging parameter requirements of the supercapacitor assembly through a full-bridge topology.

[0009] Furthermore, the microcontroller in the secondary circuit of the charger assembly collects parameters such as the temperature of the main transformer on the power board, the input voltage of the charger assembly, the output voltage of the charger assembly, the voltage of the supercapacitor assembly, the input current and the output current of the charger assembly in real time, and calculates the actual capacity and actual internal resistance of the supercapacitor assembly based on the collected parameters, and identifies the short circuit and open circuit fault states of the supercapacitor assembly.

[0010] Furthermore, the charger assembly supports three communication methods: RS485 communication, CANOPEN communication, and IO communication, so as to upload its own operating status data and fault alarm information to the main control system or pitch drive in real time.

[0011] Furthermore, the charger assembly is provided with multiple sets of functional interfaces, including at least: a digital input interface for monitoring the status of the supercapacitor assembly and various circuit breakers and fuses; a digital output interface for controlling the fault discharge assembly and outputting fault signals; an analog output interface with reserved adapter interfaces; a communication interface for data interaction; and a signal sampling interface for acquiring the voltage and temperature of the supercapacitor assembly.

[0012] Furthermore, the charger assembly is configured to: when an overvoltage of the supercapacitor assembly is detected, execute a normal overvoltage and abnormal overvoltage determination process; if it is determined to be a normal overvoltage, control the fault energy discharge component contactor to briefly engage, releasing the supercapacitor assembly voltage to a preset target voltage; if it is determined to be an abnormal overvoltage, immediately stop the voltage output and send a fault signal and overvoltage fault code to the main control system or pitch controller; after the wind turbine unit stops, control the fault energy discharge component contactor to continuously engage, releasing the supercapacitor assembly voltage to zero voltage.

[0013] Furthermore, if the actual voltage of the supercapacitor module fluctuates within ±0.5% of the rated voltage, and the number of times this overvoltage condition is triggered is ≤1 within 240 hours, it is determined to be a normal overvoltage; if the actual voltage of the supercapacitor module exceeds the range of ±0.5% of the rated voltage, the number of times it is triggered is ≥2 within 240 hours, or an overvoltage alarm signal is received from the supercapacitor module, it is determined to be an abnormal overvoltage.

[0014] Furthermore, the system also integrates a pre-test logic, which is automatically triggered before each start-up of the wind turbine. The self-test items include at least: verifying the input voltage range of the charger assembly, confirming the consistency between the DC bus voltage of the charger assembly and the preset value, checking the temperature of the main transformer of the charger assembly, verifying the ambient temperature and the temperature of the supercapacitor assembly, and checking whether the voltage and capacity of the supercapacitor assembly meet the preset number of propeller retraction operation conditions. The wind turbine is only allowed to start when all self-test items are qualified; otherwise, the wind turbine startup process is locked and a fault alarm signal is issued.

[0015] This application also protects a wind turbine generator, including the aforementioned wind turbine pitch backup power system.

[0016] The beneficial effects of this invention include: The system utilizes the physical energy storage and rapid charging / discharging characteristics of supercapacitors to fundamentally solve the millisecond-level power switching problem caused by the delayed chemical reactions of traditional batteries. It ensures stable and sufficient instantaneous power to the pitch actuator in the event of a main power failure, eliminating the risk of pitch operation interruption. The supercapacitor components exhibit significantly less capacity decay and internal resistance change compared to chemical batteries under harsh conditions such as high altitudes and low temperatures, resulting in stable discharge performance. This ensures reliable power support for the pitch actuator even in extreme low-temperature environments. Simultaneously, by integrating a charger component with intelligent management capabilities, the system can achieve real-time monitoring and precise calculation of supercapacitor voltage, temperature, capacity, and internal resistance. It can also automatically identify fault states such as capacitor short circuits and open circuits, and upload operating data and alarm information in real time through multiple communication interfaces, improving status awareness and maintenance convenience. An active safety protection mechanism is constructed through fault discharge components and intelligent overvoltage judgment logic. The entire pitch backup power system can independently perform system health checks and emergency fault handling.

[0017] The system can intelligently distinguish between normal voltage fluctuations and abnormal overvoltage faults, and adopt differentiated discharge strategies. This avoids frequent and unnecessary energy loss, and can quickly cut off the output and safely release the stored energy in the event of a real fault, preventing the fault from escalating. The system's integrated pre-detection logic automatically performs a comprehensive check on key parameters, including input voltage, component temperature, capacitor voltage and capacity, before each unit startup, ensuring that the backup power system is always in a reliable standby state. Attached Figure Description

[0018] Figure 1 This is the electrical topology diagram of the present invention; Figure 2 This is a circuit diagram of the supercapacitor assembly of the present invention; Figure 3 This is a circuit diagram of the charger assembly of the present invention; Figure 4 Circuit diagram of the fault energy dissipation component of this invention. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] Pitch backup power supplies must meet the core requirements of "rapid response, high reliability, and wide environmental adaptability." Since wind turbines often operate in harsh environments such as high altitudes, low temperatures, strong winds, high humidity, or salt spray, backup power supplies must possess excellent weather resistance and anti-interference capabilities. Simultaneously, in the event of a main power failure, power switching must be completed within milliseconds to ensure uninterrupted pitch control. Therefore, its switching response speed and power supply stability directly determine the safety level of the turbine. Based on this, this invention provides a pitch backup power supply system with rapid response, high reliability, and wide environmental adaptability to meet the safe operation requirements of wind turbines.

[0022] Example 1: An electrical schematic diagram (main topology diagram) of a wind turbine pitch backup power system is shown below. Figure 1 As shown, it includes a supercapacitor assembly, a charger assembly, and a fault discharge assembly; the supercapacitor assembly and the fault discharge assembly are electrically connected to the charger assembly and communicate with it via primary power cables and secondary signal cables; the entire pitch backup power system has independent operation capability and can autonomously complete the entire process of system health self-check, fault alarm and fault emergency handling.

[0023] The supercapacitor module consists of 120-180 Jianghai supercapacitors (divided into 2-3 groups), each with a capacity of 600F and a rated voltage of 2.7V, connected in series. As the core energy storage device, the module casing is made of PP plastic with a flame retardant rating of V2 and a rated operating temperature range of -40℃ to 70℃. Each capacitor within the module is equipped with a voltage equalization circuit to balance the voltage of each capacitor during charging. Furthermore, the supercapacitor module integrates over-temperature and over-voltage alarm circuits, outputting corresponding digital alarm signals to the charger assembly to provide comprehensive feedback on the operating status. Specifically: like Figure 2As shown, the supercapacitor module has a total of 8 interface loops, and the functions of each interface are as follows: Interface 1 / 2 is a temperature status feedback loop. When the temperature of the capacitor module exceeds 65℃, the temperature control switch changes from normally closed to normally open, feeding back the abnormal temperature status of the supercapacitor module to the charger module; Interface 3 / 4 is a temperature sampling loop, which transmits the real-time temperature of the supercapacitor module to the charger module through a PT100 sensor; Interface 5 / 6 is a voltage status feedback loop. When the real-time voltage of the supercapacitor module exceeds 160V, the varistor is triggered to conduct and transmit the overvoltage signal to the charger module; Interface 7 / 8 is a voltage sampling loop, which transmits the actual voltage to the charger module after reducing it to one-tenth through a voltage divider resistor, so as to facilitate accurate data acquisition.

[0024] The charger assembly is adapted to the rotating cabinet installation environment of the wind turbine nacelle and can independently complete the charging operation of the supercapacitor assembly. The primary circuit of the charger assembly includes a rectifier board and a power board. The rectifier board converts the input three-phase AC power into DC power, and the power board converts the DC power into DC power that meets the charging parameter requirements of the supercapacitor assembly through a full-bridge topology. The secondary circuit of the charger assembly integrates a microcontroller to collect parameters in real time, such as the temperature of the main transformer on the power board, the input voltage and output voltage of the charger assembly, the DC bus voltage, the voltage of the supercapacitor assembly, the input current and the output current of the charger assembly. Based on the collected parameters, it calculates the actual capacity and internal resistance of the supercapacitor assembly and identifies short-circuit and open-circuit fault states of the supercapacitor assembly, thereby realizing multiple protections against over-temperature, over-voltage, and over-current, while accurately controlling the output voltage and output current of the charger assembly. The charger assembly supports three communication methods: RS485 communication, CANOPEN communication, and IO communication, to upload its own operating status data and fault alarm information to the main control system or pitch drive in real time.

[0025] like Figure 3As shown, the charger assembly has 5 sets of functional interfaces (X1-X5): Interface X1 is a digital input interface, where ports 1 / 2 / 3 are used to monitor the temperature status of 3 sets of supercapacitors (low level indicates abnormality), ports 4 / 5 / 6 are used to monitor the overvoltage status of 3 sets of supercapacitors (high level indicates abnormality), ports 8 / 9 / 10 are used to monitor the status of output fuse F1, pitch drive input circuit breaker Q3, and energy leakage circuit breaker Q2 respectively (low level indicates abnormality), and port 7 is a reserved interface for adapting to different types of pitch drives; Interface X2 is a digital output interface, where port 1 is used to control the engagement and disengagement of energy leakage contactor KM1, and port 2 is used to output to... The pitch driver / main control system outputs fault signals. Ports 3 / 4 / 5 / 6 / 7 are reserved interfaces for adapting to different types of pitch drivers. Interface X3 is an analog output interface, with ports 1 / 2 / 3 being reserved interfaces for adapting to different types of pitch drivers. Interface X4 is a communication interface, supporting RS485 and CANOPEN communication protocols for data exchange. Interface X5 is a temperature sampling interface (PT1 / PT2 / PT3) for accurately measuring the real-time temperature of the three sets of supercapacitor modules. Interface X6 is a voltage sampling interface (VOL1 / VOL2 / VOL3) for accurately measuring the real-time voltage of the three sets of supercapacitor modules.

[0026] The fault energy dissipation component includes a high-power resistor, a circuit breaker, and a contactor; the high-power resistor is connected to the supercapacitor component in sequence through the circuit breaker and the contactor to form an energy dissipation circuit; and the charger component controls the contactor coil to open and close through a digital output signal to control the opening and closing of the energy dissipation circuit.

[0027] When the charger assembly detects overvoltage in the supercapacitor assembly, it executes a normal overvoltage and abnormal overvoltage determination process. If the actual voltage of the supercapacitor assembly fluctuates within ±0.5% of the rated voltage, and the number of times this overvoltage condition is triggered is ≤1 within 240 hours, it is determined to be a normal overvoltage. In this case, the fault discharge component contactor is briefly engaged to release the supercapacitor assembly voltage to the preset target voltage. If the actual voltage of the supercapacitor assembly exceeds ±0.5% of the rated voltage, the number of triggers is ≥2 within 240 hours, or an overvoltage alarm signal is received from the supercapacitor assembly, it is determined to be an abnormal overvoltage. In this case, the voltage output is immediately stopped, and a fault signal and overvoltage fault code are sent to the main control system or pitch controller. After the wind turbine is shut down, the fault discharge component contactor is continuously engaged to release the supercapacitor assembly voltage to zero voltage, ensuring safe operation and maintenance.

[0028] Example 2: Based on Example 1, the system also integrates a pre-test logic, which is automatically triggered before each start-up of the wind turbine; the self-test items include at least: (1) Verify the input voltage range of the charger assembly (whether the input voltage of the charger assembly is within the range of 3×184VAC~3×480VAC / 2×230VAC±20%) to verify the stability and compliance of the charger power input; (2) Confirm that the DC bus voltage of the charger assembly is consistent with the preset value (whether the DC bus voltage of the charger assembly is consistent with the preset output voltage of 300VDC-480VDC) to ensure that the DC output performance of the charger meets the standard; (3) Check the temperature of the main transformer of the charger assembly (whether it is within the range of -40℃ to 105℃) to prevent the power board from failing to work properly due to overheating or low temperature; (4) Verify the ambient temperature and the temperature of the supercapacitor components (whether they are within the range of -40℃ to 65℃) to verify whether the external environment and the supercapacitor components meet the operating conditions. (5) Check whether the voltage and capacity of the supercapacitor assembly meet the preset number of propeller retraction operation conditions (preferably set to three times) to ensure that the supercapacitor can support the completion of the propeller retraction operation in emergency situations.

[0029] The wind turbine is only allowed to start when all self-test items pass; otherwise, the wind turbine startup process is locked and a fault alarm signal is issued.

[0030] This detection logic proactively identifies potential faults in core components such as chargers and supercapacitors through pre-emptive protection, multi-dimensional parameter coverage, adaptation to different scenarios, and targeted emergency protection. This prevents equipment damage or downtime caused by operating with faults, ensures the reliability and emergency response capability of the pitch backup power system, and provides strong support for the safe and stable operation of wind turbines.

[0031] Example 3: This invention possesses broad equipment adaptability, compatible with pitch drives from various manufacturers currently on the market. In the primary circuit, it can output variable and stable DC power within the range of 300V-480V, meeting the main power requirements of the pitch drive. In the secondary circuit, this invention is equipped with RS485, CANOPEN, and IO communication interfaces, enabling precise matching with different types of pitch drives. Simultaneously, it can output real-time, comprehensive key data required for pitch drive operation, including real-time voltage, input current, and temperature of the supercapacitor assembly; input voltage and current of the charger; real-time temperature of the power board; DC bus voltage; output voltage and current; and external circuit breaker status, comprehensively supporting real-time monitoring and refined operation and maintenance of the pitch drive.

[0032] This invention can be used for the installation of newly designed wind turbine units, as well as for the retrofitting of backup power supplies for the pitch systems of existing wind turbine units. Retrofitting existing units mainly involves the following: 1) Based on the original pitch power supply's structural dimensions, a customized structural design is carried out, and the supercapacitor assembly, charger assembly, and fault discharge assembly of this invention are installed at the original backup power supply installation location. 2) Power is drawn from the original pitch system input power supply and used as the input power supply for the charger; 3) Connect the output of the supercapacitor assembly to the DC power supply circuit of the pitch driver to ensure the smooth operation of the emergency power supply link; 4) Based on the original pitch system's communication protocol, complete the software matching and wiring debugging to ensure normal data interaction.

[0033] In summary, the present invention has the following advantages: 1. The response speed is more timely, and it can achieve millisecond-level charge and discharge switching, which can instantly provide sufficient power to the pitch drive and accurately match the "zero-delay" emergency power supply needs after the main power supply fails; 2. Longer cycle life, with tens of thousands or even hundreds of thousands of charge-discharge cycles, far exceeding the thousand-cycle life of batteries, which can significantly reduce the frequency of equipment replacement and save long-term operation and maintenance costs. 3. Stronger low-temperature adaptability: In the high-altitude low-temperature environment (such as -30℃ and below) commonly encountered by wind turbines, the capacity decay is small and the discharge performance is stable, while batteries are prone to problems such as sudden capacity drop and difficulty in starting in such environments. 4. Enhanced safety performance: The charging and discharging process is a physical reaction, eliminating the risks of overcharging explosions, leaks, thermal runaway, and chemical pollution, making it perfectly suited for the enclosed and high-risk operating environment of the engine room. 5. Lower maintenance costs: Unlike batteries, it eliminates the need for cumbersome maintenance procedures such as regular water replenishment and equalization charging, making it more suitable for the practical scenario of high-altitude operation and maintenance of wind turbines. The secondary circuit of the charger assembly integrates a microcontroller, which controls the constant current and constant voltage charging of the energy storage unit (supercapacitor assembly) when the main power supply is normal, while monitoring the energy storage status. In the event of a main power failure, it automatically switches to discharge mode to output the required voltage and current to the pitch driver. The charger assembly monitors the voltage, current, temperature, and other parameters of the backup power supply in real time. When abnormal conditions such as overcharging, over-discharging, over-temperature, or short circuit occur, the protection mechanism is immediately activated to prevent equipment damage or safety accidents.

[0034] 6. Independent system: The backup power system has the ability to operate independently. It can operate independently of the pitch controller and the main control system, and can autonomously perform self-health checks and implement protection actions. The system operating status and fault details will be transmitted to the pitch controller or the main control system through a dedicated communication channel to realize real-time interaction and closed-loop management of status information.

[0035] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A wind turbine pitch control backup power system, characterized in that, It includes a supercapacitor assembly, a charger assembly, and a fault discharge assembly; the supercapacitor assembly and the fault discharge assembly are both electrically connected to and signal-communicate with the charger assembly through primary power cables and secondary signal cables; The supercapacitor assembly consists of multiple supercapacitors connected in series. Each capacitor in the module is equipped with a voltage equalization circuit. The supercapacitor assembly also integrates an over-temperature alarm circuit and an over-voltage alarm circuit to output corresponding digital alarm signals to the charger assembly. The charger assembly includes a primary circuit and a secondary circuit. The primary circuit is used to convert external input AC power into DC power that meets the charging requirements of the supercapacitor assembly. The secondary circuit integrates a microcontroller for collecting system parameters and calculating the supercapacitor status. The fault energy dissipation component includes a high-power resistor, a circuit breaker, and a contactor; the high-power resistor is connected to the supercapacitor component in sequence through the circuit breaker and the contactor to form an energy dissipation circuit; and the charger component controls the contactor coil to open and close through a digital output signal to control the opening and closing of the energy dissipation circuit.

2. The wind turbine pitch backup power system according to claim 1, characterized in that, The supercapacitor module integrates an over-temperature alarm circuit and an over-voltage alarm circuit. Specifically, the supercapacitor module has multiple external functional interface circuits, including at least: The temperature status feedback loop uses a temperature control switch to provide feedback on whether the temperature exceeds the threshold. The temperature sampling loop collects and transmits the real-time temperature of the supercapacitor component through the temperature sensor transmission module; The voltage status feedback loop uses a varistor to provide feedback on whether the voltage exceeds a threshold. The voltage sampling circuit outputs the actual voltage of the supercapacitor component after proportional attenuation through a voltage divider circuit.

3. A wind turbine pitch control backup power system according to claim 2, characterized in that, The primary circuit of the charger assembly includes a rectifier board and a power board. The rectifier board converts the input three-phase AC power into DC power, and the power board converts the DC power into DC power that meets the charging parameter requirements of the supercapacitor assembly through a full-bridge topology.

4. A wind turbine pitch backup power system according to claim 3, characterized in that, The microcontroller in the secondary circuit of the charger assembly collects parameters in real time, including the temperature of the main transformer on the power board, the input voltage of the charger assembly, the output voltage of the charger assembly, the voltage of the supercapacitor assembly, and the input and output current of the charger assembly. Based on the collected parameters, it calculates the actual capacity and internal resistance of the supercapacitor assembly and identifies short-circuit and open-circuit fault states of the supercapacitor assembly.

5. A wind turbine pitch backup power system according to claim 4, characterized in that, The charger assembly supports three communication methods: RS485 communication, CANOPEN communication, and IO communication, so as to upload its own operating status data and fault alarm information to the main control system or pitch drive in real time.

6. A wind turbine pitch backup power system according to claim 5, characterized in that, The charger assembly is provided with multiple sets of functional interfaces, including at least: a digital input interface for monitoring the status of the supercapacitor assembly and various circuit breakers and fuses; a digital output interface for controlling the fault discharge assembly and outputting fault signals; an analog output interface with reserved adapter interfaces; a communication interface for data interaction; and a signal sampling interface for acquiring the voltage and temperature of the supercapacitor assembly.

7. A wind turbine pitch backup power system according to claim 6, characterized in that, The charger assembly is configured to: when an overvoltage is detected in the supercapacitor assembly, execute a normal overvoltage and abnormal overvoltage determination process; if it is determined to be a normal overvoltage, control the fault energy discharge component contactor to briefly engage, releasing the supercapacitor assembly voltage to a preset target voltage; if it is determined to be an abnormal overvoltage, immediately stop the voltage output and send a fault signal and overvoltage fault code to the main control system or pitch controller; after the wind turbine unit stops, control the fault energy discharge component contactor to continuously engage, releasing the supercapacitor assembly voltage to zero voltage.

8. A wind turbine pitch control backup power system according to claim 7, characterized in that, If the actual voltage of the supercapacitor module fluctuates within ±0.5% of the rated voltage, and the number of times this overvoltage condition is triggered ≤1 time within 240 hours, it is determined to be normal overvoltage; if the actual voltage of the supercapacitor module exceeds the range of ±0.5% of the rated voltage, the number of times it is triggered ≥2 times within 240 hours, or an overvoltage alarm signal is received from the supercapacitor module, it is determined to be abnormal overvoltage.

9. A wind turbine pitch backup power system according to any one of claims 1-8, characterized in that, The system also integrates a pre-test logic, which is automatically triggered before each start-up of the wind turbine. The self-test items include at least: verifying the input voltage range of the charger assembly, confirming the consistency between the DC bus voltage of the charger assembly and the preset value, checking the temperature of the main transformer of the charger assembly, verifying the ambient temperature and the temperature of the supercapacitor assembly, and checking whether the voltage and capacity of the supercapacitor assembly meet the preset number of propeller retraction operation conditions. The wind turbine is only allowed to start when all self-test items are qualified; otherwise, the wind turbine startup process is locked and a fault alarm signal is issued.

10. A wind turbine generator set, characterized in that, Includes the wind turbine pitch backup power system as described in any one of claims 1-9.

Images