Characteristics of Electric Motors

Speed Torque Characteristic DC Shunt Motor: The preceding discussion shows that armature voltage variation gives creeping speeds. The simple rheostatic method provides a Speed Torque Characteristic DC Shunt Motor with little hardness and little stability. Ward Leonard control (smooth variation of voltage), on the other hand, produces a flat characteristic with reasonable hardness and stability, […]

Speed Torque Characteristic of Separately Excited DC Motor: The circuit equation of a Speed Torque Characteristic of Separately Excited DC Motor whose armature, having a total of Z con­ductors, is wound for 2P poles (the brushes divide the winding into 2a parallel paths), is Where E is the back emf of the armature given by

Characteristics of DC Motor: DC Motors are of the rotating armature type. The armature winding is a closed winding through the commutator. The armature is supplied through the brushes which are placed along the neutral axis on the commutator. The field system is stationary. The mmf produced by the field is along the magnetic axis

A Simple Electric Motor: Variable speed drives in the industry employ a simple electric motor as their drive motors mainly because they enjoy several specific advantages, such as overload capacity, smooth speed control over a wide range, capability of operating in all the four quadrants of the speed-torque plane, etc. Till the advent of thyristors