Implementation of an on-line simulator for sensorless permanent magnet synchronous motor drives

This paper describes the design and the implementation of an online simulator for simulating the operation of sensorless permanent magnet synchronous motor drives for electric vehicles. The mathematical model of the motor is constructed in a natural reference frame. Simulated motor currents and voltages are used to estimate the flux linkage of the motor. Calculations of the rotor position is based on the estimated flux linkage. A vector controller designed in the d-q frame provides constant torque and constant power control. A hysteresis current controller is employed in the drive to generate the switching signals for the inverter. Starting procedures and transition from one drive region to another within an operation duty cycle are discussed. The simulator, implemented with MATLAB, is tested with a step input from standstill and a step load change at steady state