Model Parameters Identification And Control Of High Voltage High Power Variable Frequency Drive

As a result of the significant technological innovation in Electrical Drive field ,AC Speed regulating technology has developed rapidly in situation of energy lack, which applied more and more widely in industry. Research and develop high voltage inverter can reduce energy wastage greatly as 70% energy charge of whole motor is consumed by those rated voltage more than 1KV, which will contribute a lot to the economy society.In practice, technics or related problems often require inverter's strong speed regulating ability. Flux estimation and parameters identification are the critical technologies in high-performance inverter, and have become the hotpot of research. This paper summarized different models of three-phase AC motors in three classic coordinates based on space vector analysis, compared excellence and disadvantage of two kind of familiar flux estimators, and simulated them by Matlab/Simulink. Results of simulation showed that the estimated value accord with real value. Current type rotor flux estimator was realized in the project, which contribute a lot to the vector control of high power variable frequency adjustable speed drives.Traditional ways of identification of motor parameters are tiresome and time-consuming, and the data acquired is not accurate. This paper proposed a method which gained the motor parameters using the instant response of AC induction motor to voltage pulse and current pulse when the motor not running. Simulation by Matlab/Simulink proves the method's feasilility. Some motor parameters such as rotor resistance and time-constant, vary easily and greatly, which influence the performance of inverter, so they should be identified on-line. This paper build the rotor resistance's identification model three-phase induction motor, detect the rotor resistance and estimate rotor current and stator current using the EKF arithmetic through simulation.Besides, this paper designed the part hardware of the high voltage inverter developed in the project. In order to verify the inverter's performance, Load experiments have been done. Results show that the sample inverter has strong timing performance and can work stably when speed is low.