Frequency-current method of controlling an asynchronous three-phase motor

Abstract

Object and purpose of research. This paper discusses the method for controlling an asynchronous motor (AM), based on maintaining the optimal frequency of the rotor currents, which corresponds to the maximum electromagnetic moment of the rotor, and controlling its value by regulating the stator currents.
 Materials and methods. The mathematical model of asynchronous motor adopted in this study assumed the stator to be powered by a controlled three-phase AC generator. The functional diagram of motor speed control system and its digital model in the Matlab Simulink system have been developed.
 Main results. The constructed mathematical model of AM is correct under condition of smooth changes in set frequency and amplitude of stator currents governed by three-phase stator current control loop practically without error.
 Conclusion. The proposed method for controlling AM does not require complex calculations and is not too demanding in terms of computer hardware resources.