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