Realistic modeling of torque DC machines by SPICE

The modeling of the variation of torque in a PWM driven separately excited DC motor due to speed and number of rotor phases is investigated. This torque ripple effect can be reduced by changing the duty cycle which in turn is altered by sensing the speed of the motor. These models enable designers to realize and estimate the torque ripple effect of a DC motor drive and hence design a drive circuit to match the DC machine more easily and accurately. SPICE simulation program is used as a tool