Parameter Identification of Inverter-Fed Induction Machines at Standstill Based on Signal Injection

This paper proposes a novel method for parameter identification of the induction machines (IMs) fed by PWM inverters at standstill. Two different AC voltages (1.2 V/200 Hz and 0.7 V/10 Hz), which are superimposed on DC bias, are injected into the IM from a PWM inverter for the identification of the transient inductance and rotor resistance, respectively. During identification process, the phase difference between stator voltage and current is obtained by using the third-order generalized integrator (TOGI). Since the TOGI behaves like an adaptive filter, the identification results are robust to the measurement noises. By the DC step-voltage test, the rotor time constant is estimated. The experimental results have demonstrated the feasibility of the proposed method.