Research on Low Frequency Oscillation of Induction Motor in Discontinuous Power Supply Mode

Symmetrical components method was adopted to study the oscillation of induction motor driven by thyristors. This was the simplest discontinuous supply mode and excluded the influence of inductance and capacitance on the inverter side. The transient process and variation of speed during phase-exchange period were analyzed when the motor was supplied by two and three phase voltage, and the space vector expressions of stator and rotor current during different transient processes were deduced, and their solutions in time domain were given. The cause of oscillation was found out when induction motor worked at discontinuous power supply, and explanation of oscillation was presented from the view of the motor itself. A three phase induction motor was analyzed using the method given above, and it was proved that calculation results were very close to the experiment results, and this method can be the basis for transient process study of induction motor supplied by inverters.