Group Induction Motors’ Speed Control via ACPWM-Based Single Speed Controller

In a bid to optimise our energy consumption, we humans are heading towards the more feasible ways of doing things. This led us to switch from fossil fuel powered drive to electrical drives. So, in early twentieth century, the trend to use DC drive had picked up as it was easy to regulate the speed of DC drive than AC drive. DC drive speed control have many limitations as it does not have the broad speed control range and was less efficient. But with the advancement in the semiconductor technology, it became easy to regulate the speed of AC drives. There are many methods by which we can vary the induction motor speed such as: by changing the pole of induction motor, by varying the terminal voltage, by varying the frequency of input current, etc. This paper proposes to control the induction motor speed using ACPWM technique. It is a new approach to regulate the induction motor speed by varying the stator terminal voltages. This is an alternative for TRIAC-based phase angle control method which is not very efficient for speed control of high ratings induction motors due to their high inductive effect. The new ACPWM technique provides the better performance of the machine by reducing higher order harmonics as compared to TRIAC-based method. This technique is elaborated in further part of the paper.