On the analysis of current source inverter fed permanent magnet synchronous motor

Digital computer simulation is presented for the steady-state analysis of a load commutated invertor-fed permanent magnet synchronous motor in the self-controlled mode under noninstantaneous commutation of the inverter. Both types of rotor configuration (surface mounted permanent magnet-SPM and interior permanent magnet-IPM) are considered. A simple state-space mathematical model which describes the motor-inverter combination in the interlude and commutation periods, is used for digital simulation. The performances of SPM and IPM motors are compared. The digital computer results present the behaviour of phase currents, torque pulsations and phase voltages. The simulation results show that the performance of the motor is affected not only by the individual values of inductances but also by their ratio which is identified as a saliency coefficient. Increase in inductances limits the highest frequency of operation while improving the torque characteristics of the motor.