ELEC4613 Electric Drive Systems University of New South Wales School of Electrical Engineering & Telecommunications Tutorial 2. Controlled converter driven DC motor PWM converter driven DC motor 1. A separately excited DC motor has the following parameters: Varated = 250 V, Ra = 2.5 9, la rated = 20 A. The motor is driven by a 1-Q DC-DC converter (chopper) as indicated in figure 1, which has a switching frequency of 400 Hz. With the rated voltage and rated torque applied, the motor runs at 600 rev/min