Compensation of Inverter Nonlinear Distortion Effects for Signal-Injection-Based Sensorless Control

A simple analytical technique, which uses readily available datasheet parameters, is developed to model the low-current switching characteristics of insulated-gate bipolar transistors (IGBTs). Simulation and experimental results obtained using three differently rated inverters are presented to demonstrate the accuracy of the technique. The model is applied to compensate the nonlinear distortion, introduced by IGBT switching action in a three-phase inverter, of high-frequency injected voltage and current signals used in sensorless control of a permanent-magnet brushless ac machine. Experimental results show that the compensation technique improves rotor position estimation by up to 20° electrical.