A 3-Φ full converter is used to control the speed of a 100hp, 600V, 1800rpm, separately excited DC motor. The converter is operated from 3-Φ, 480V, 60Hz supply. The motor parameters are Ra=0.1 ?, and La=0.5mH, KØ=0.3V/rpm. Rated armature current is 130A.
a. Rectifier Operation: The motor is running at rated conditions at 1500rpm. Assuming ripple free current,
Determine,
1.Firing angle α, and
2.Supply power factor.
b. Inverter Operation: The DC machine is operated in regenerative braking mode at 1000rpm and rated motor current.
Determine:
1. Firing angle α,
2. The power fed back to the supply, and
3. Supply power factor.