Evaluation of relative stability of an induction motor driven by voltage-type inverter via performance indexes

Stability, performance, and an estimation of transient response are analyzed by applying the second method of Lyapunov. It is shown that instability phenomena, which occurs when the ratio of the induction motor terminal voltage to frequency is constant, can be prevented by decreasing the filter nominal impedance (or by decreasing the series impedance and increasing the shunt capacitance) or by employing a pulse width control scheme. A feedback control system should be applied in the case when the response characteristics worsen due to the shunt capacitance increase. The effect of the current feedback control on the relative stability of the induction motor driven by a voltage-type inverter is studied.