Study of Parameter Sensitivity in High-Performance Inverter-Fed Induction Motor Drive Systems

Vector control schemes are used in inverter-fed induction motor drives to obtain high performance. Crucial to the success of the vector control scheme is the knowledge of the instantaneous position of the rotor flux. The position of the rotor flux is measured in the direct scheme and estimated in the indirect schemes. Since the estimation of the flux position requires a priori knowledge of the induction motor parameters, the indirect schemes are all machine-parameter dependent. Changes in temperature and saturation levels of the machine vary the machine parameters and, hence, indirectly influence both the steady state and the dynamic operation of the drive system. Analytic expressions are derived to evaluate the effects due to parameter sensitivity. The simulation is experimentally verified on a drive system.