Back e.m.f
Field current
Terminal voltage
Armature current
Inverter switching device
D.C bus switching device
Rectifier switching device
Field supply switching device
Converts A.C to D.C
Converts A.C to A.C
Converts D.C to A.C
Converts D.C to D.C
Easy to operate
Robust in construction
Very high starting torque
Maintenance free long life
By reducing the field current
By increasing the field current
By increasing the supply voltage
By reducing the armature voltage