A SOLID STATE INVERTER FED INDUCTION MOTOR DRIVE

Abstract

has been revolutionized with the development of solid state s siconductor devices (such as silicon controlled rectifiers,, power diodes and power transistors etc.). Also the fast developments in Power Electronics have opened up new vistas in the field of static control of electric drives that are gaining more and more popularly. An electric drive basi-cally consists of an electric eachine associated with a control equipment (that may include a frequency converter rectifier eta.) to convert electrical energy into a mechanical energy and thereby to provide a versatile control of speed,, torque etc. `.,of the electric machine. Moorral1y., among the statically controlled electric drives, a doe* motor operated an a variable speed drive by a static power controller is a popular choice. But the min draw backs of a dec. motor are I- (1) Increase In cost and decrease in power/weight ratio because et to bo7ai mechanical commutator. (ii) Accentuated sparking at high currents and speeds. (iii) A limited armature voltage rating inherent in d.c. machines. (iv) A limited armature current# because of oommitation probl e+.