Research On Speed Sensorless Control Strategy Of Induction Motor

Induction motors are widely used in a variety of industrial fields,for its simple structure and durability.In order to reduce the volume and cost of induction motor driving systerm,meanwhile increase the entire reliability,speed sensorless control technology has been studied in depth by scholars at home and abroad,as a key technology of high-performance induction motor control.In this paper,speed sensorless control technology based on extended Kalman filter(EKF)is studied for three-phase induction motor driving system.Firstly,the mathematical models of three-phase induction motor in different coordinate systems are established.The theory of motor vector control,including controller design and SVPWM technology,is introduced and analyzed in detail.Corresponding simulation results show that the adopted control strategy has satisfactory performance.Secondly,the principle of Kalman filter is analysed from the perspective of filter objective function.After choosing the suitable state variable and establishing the state space equation of induction motor,steps of EKF are studied.The closed-loop performance and anti-jamming performance of driving systerm are verified by simulation.Considering the large amount of matrix multiplication in EKF,according to the theory of least mean square estimation in complex domain,the Complex-EKF is proposed to optimize the traditional EKF algorithm on the basis of complex state equation of induction motor.The closed-loop performance and anti-jamming performance of this algorithm are verified by simulation.To realize the proposed speed sensorless control scheme for induction motor,experimental platform is bulit in this paper and TMS320F28335 chip of Texas Instruments is taken as core of the platform.In addition,hardware and software design of the platform are introduced in detail,the experimental results of speed sensorless control based on EKF and Complex-EKF are given to verify the validity of the control algorithm.