The protection of the frequency limit. This kind of protection is mainly used to quickly cut off the fan when the frequency fluctuates greatly. The fluctuation of the frequency in the power grid will cause damage to the normal operation of the fan. When the frequency in the power grid is higher than the fan limit, the over-limit protection will immediately remove the fan. The frequency limit protection is typically 50.5 Hz or less than 49.5 Hz, and the delay is less than or equal to 100 ms. Current protection. In general, wind opportunities are equipped with current quick-break protection and over-current protection to protect the current. In addition, the wind turbine is equipped with three-phase current, voltage imbalance protection, fan temperature rise, speed rise, vibration exceeds limits and cable twisting and other related protection. For variable speed constant frequency fans, the converter is used for large area decoupling control of the vector. At present, basically all wind farms use a doubly-fed induction generator. When the doubly-fed wind turbine is connected to the grid, the voltage on the stator side is 690V AC. When the grid fails, the grid will be reduced. In this case, the stator flux linkage cannot be synchronized with the terminal voltage. To ensure that the stator chain does not change, take measures to protect against overvoltage and overcurrent. At present, the protection of converters for doubly-fed wind turbines is usually carried out by crowbar protection. The parameters connected to the crowbar protection system are: DC link overvoltage, grid side converter branch overcurrent, rotor overcurrent, etc. Rotor Core,Copper Rotors,Copper Rotors With Shafts,Rotor Assembly Henan Yongrong Power Technology Co., Ltd , https://www.hnyongrongglobal.com
What is the wind turbine protection?
The wind turbine needs to have the provisions of the "Technical Regulations for Wind Farms Connecting to the Power Grid" formulated by State Grid Corporation of China. When the voltage of the wind turbine in the wind farm falls to 20% of the rated voltage at the grid connection point (that is, the node or busbar on the high voltage side of the wind farm step-up transformer), it must have a continuous operation for 625 ms without off-grid. Capacity; wind turbines in wind power plants should rise to 90% of the rated voltage within 2 s after the voltage drop at the grid-connected point, and no off-grid can occur.