Speed control of induction motors using proposed closed loop Volts/hertz control scheme

Volts/hertz (V/Hz) control of three-phase induction motor is popular control method, although of low dynamic performance, because of its simplicity and low cost. Closed loop system, including an appropriate controller, is used to obtain a good speed control. Proportional-integral (PI) controller is commonly used, and good design of this controller requires an accurate mathematical model of the system. Another controller is the fuzzy logic controller, where linguistic rule base, based on human expertise, is used. Therefore, obtaining a good controller may violate the simplicity of V/Hz control system. In this paper, a simple V/Hz control system is proposed. The control method is straight forward and does not depend on accurate mathematical models or human expertise.