Double-fed Asynchronous Induction Generator Fault Diagnosis Technology Based On Electrical Signals

Wind energy is the fastest growing and most promising clean energy in recent years, and already become an important part of the world's energy mix. Its average annual growth rate is more than 20%. But the cost of wind power per kilowatt-hour (kWh) is still higher than conventional energy significantly, which seriously restricted the development and utilization of wind energy. The method of condition monitoring and fault diagnosis technology based on vibration signals is already put into practice on wind turbines. But it needs many sensors to install, and depends on the sensor, which reduces the wind turbines reliability. To reduce the cost of wind energy development, and to overcome shortcoming of the traditional methods of equipment maintenance and condition monitoring and fault diagnosis technology based on vibration signals, this paper based on electrical parameters of the wind turbines.Wind energy captured by wind turbine is transformed to the generator by the drive chain. The generator converts wind energy to electricity, and output to the grid. Wind turbine, generators, transmission chain and a part of any power failure affects the quality. Therefore, the principle of the doubly-fed asynchronous induction generator is analyzed to research the current and voltage characteristics of fault components units. The fault states of doubly-fed asynchronous induction generator on the main components are modeled and simulated to verificate the accuracy of electrical signals characteristics. Wavelet packet is utilized to denoise and extract fault features according to modern fault diagnosis. Then multi-level neural network is constructed and trained. Its accuracy is showed by simulation and experiment.Intelligent fault diagnosis system based on current and voltage signals is designed and implemented according to wind farm monitoring network. It's great important and valuable to the wind turbines fault diaglosis...