Mumbai University > Electronics Engineering > Sem7 > Power Electronics 2

Marks: 5M

An electric motor is the source of motive power. An energy transmitting device delivers power from electric motor to the driven machine (load)

• A working machine is the driven machine that performs the required production process. E.g. Centrifugal pumps, conveyor belts etc.

• An electric motor together with its control equipment and energy transmitting device forms an electric drive.

• An electric drive together with its working machine constitutes an electric drive system.

• Fig 4.1 shows an electric drive system. The electric drive, consisting of electric motor, its power controller and energy transmitting shaft is also indicated in fig 4.1. DC motors are used extensively in adjustable speed drives and position control applications. Their speed below base speed can be controlled by armature – voltage control. Speed above base speed can be controlled by field – flux control.

• The DC motors used in conjunction with power electronic converters are dc separately excited motors or dc series motors.