Speed sensorless vector controller using high frequency injection in induction motor

摘要

The present invention relates to a speed sensorless vector controller using high frequency injection in an induction motor. In the prior art, the response to the load torque at the time of starting is delayed in many cases, There is a problem in application of the load. Therefore, in the present invention, the position and velocity observers in the speed sensorless controller using the high-frequency injection are multiplied by the high-frequency current, the cosine function and the sine function obtained by dividing the high frequency detection current having the polarity information into the q-A heterodyne processing unit 22A for outputting an error signal obtained through a new heterodyne process for obtaining a difference between multiplied values, a low pass filter 22A for outputting a filtering error signal obtained by performing low pass filtering on the error signal, An observer controller 22C which receives the filtering error signal output from the integrator 22B and calculates a magnetic flux speed estimation value through an integrator and a gain control, and a gain control unit 22C which receives gain control of the slip speed of the induction motor A speed compensator 22E for outputting a speed compensated magnetic flux speed compensation estimated value, Configured as an integrator (22D) to integrate the value of the magnetic flux to obtain the location estimate, in the sudden change of the load and accurately estimate the speed and position of the magnetic flux, it is a transient state to improve the torque response always enables a successful start-up.