Research On The Fault Diagnosis And Monitoring System Of Wind Power Converter

Wind energy is a renewable and clean energy, and it has been widely used in almost all the countries in the world. The development and utilization of wind energy advance rapidly, but the failure ratio of the wind turbine is bigger and bigger, which has impacting on the reliability of the grid operation when wind farm integration. As a result of that, the wind turbine fault diagnosis technology is badly in need of improvement. As the main component of energy conversion of wind turbine, the converter works relatively in poor stability, and its operational states should be paid more attention about. So the monitoring platform and fault diagnosis technology play a very important role in guaranteeing the power supply efficiency and economic benefit of a wind turbine.The monitoring platform and fault diagnosis technology of the converter are investigated in this paper based on the project of the development of a3MW wind power converter. At first, the main fault types, reasons of fault occurrence and their detecting methods of the converter is discussed. Then the advantages of the two open circle fault diagnosis methods of the inverter, which based on current and voltage, is compared. After that, combined the basic detect principle and the grid side inverter model of the four parallel converter system, the fault behaviors of open circuit, short circuit and driving of the power switch tube are discussed.A simulation model of the full power converter of wind turbine with cage type asynchronous generator is also established based on Matlab/Simulink platform, and then the simulation research of the open circuit fault of the parallel inverters is carried out. Furthermore, the waveform characteristics of the parallel inverters are analyzed, and its good redundancy and fault-tolerant performance is verified by simulation as well. After that, a practical fault diagnosis method for parallel grid side converter is presented. This method is simple in principle but good practicability and is proved by both simulation and experiment.In addition, a wind power converter monitoring system based on Lab VIEW and PXI bus is developed. It can monitor real-time voltage、current and temperature of the wind power converters and has been used in the development and debugging of wind power converter in the laboratory. It can deal with signal filtering, curve fitting, harmonic analysis, fault alarm, and can accurately reflect the state of the converter in transient or steady state operation. And more, it has character of interface friendly and good extendibility on software and hardware so as to satisfy different experiment conditions. The system can also realize remote monitoring of the wind power converter that operates in a wind farm. It can be said that it has a broad application prospect in the field of the wind power generation.