Impact of asymmetrical phenomena on asynchronous three-phase motors in operation mode

Abstract

The general theory of three-phase motors is often built based on the assumption that the three phases voltage is symmetrical. However, in practice, this operation mode of the motor cannot be achieved due to a number of reasons such as the structure of the motor is not symmetrical, the load in the electrical system is not balanced. The asymmetry of threephase voltage greatly affects the operation mode of a three-phase asynchronous motor. The most serious affections are: decrease the starting torque, increase stator current and rotor current, vibration inside the motor. This affection will reduce the effective operation of the motor. The paper investigates the effect of asymmetry voltage on the normal operation mode of a three-phase asynchronous motor based on the electromagnetic transforming method of electric machines and simulating on Matlab-Simulink.