Study On Identification Method Of Speed Sensorless For Double Fed Induction Motor Control

With the development of AC drive technology, speed-sensorless control system of doubly-fed induction motor has obvious advantages in some high voltage, high power applications. It has a fast dynamic response, low harmonic pollution, high efficiency and other characteristics. And the device is simple, has good reliability and small power inverter. There is important theoretical value and practical significance of their detailed study.On the basis of consulting a large number of literature and books, elaborated the development status of DFIM control systems and Speed-Sensorless control system,Got the advantage of Speed-Sensorless control system: DFIM of Speed-Sensorless control system is introduced to improve the system reliability and environmental adaptability, expanding the doubly-fed motor speed control system applications.First elaborated mathematical model of the motor, presented DFIM mathematical model at the three-phase stationary coordinate system and the two-phase synchronous rotating coordinate system, elaborated the principle of double-fed motor speed control and a variety of operating conditions.On the basis of mathematical model of DFIM, done a comparison of various orientation vector, select the relatively better stator flux oriented programs, and according to the theoretical analysis, got a flux observer model which can eliminate Integral drift. Then deduced DFIM vector control equation based stator flux oriented, and the simulation experiments have proved the effectiveness of the proposed control strategy.For speed observer, have proposed model reference adaptive(MRAS) method and the rotor high frequency signal injection method. Constructed the voltage model as a reference model and the current model as a variable model based on the mathematical model of the motor, designed adaptive law based on Popov super stable management. Then, conducted a simulation proved that it has a good effect of the rotation speed observer when high-speed operation, and achieved good dynamic and static performance. For speed observation of DFIM in Low speed operation, proposed high frequency injection method. Injection high frequency signal in Rotor-side, then extracts a high frequency signal including the rotation speed information from the stator side. Then demodulated to get the motor speed, and the simulation results has shown the effectiveness of this method.