Design and Development of ACPWM Based Dominant Speed Controller for Multiple Induction Motors

This paper proposes a distinct speed control approach for series connected multiple single phase AC induction motor connected to a common power supply and speed controller. PWM modulated source voltage is supplied to group of single-phase induction motors leading to highly efficient and low-cost drives. An AT89C51 (8051) microcontroller connected to opto-isolator is the main functional element which would provide the desired firing angle pulse to IGBT based controller. When compared to TRIAC-based phase angle control drives, this controller would provide the better results. It assists in supplying pertinent variable AC voltage to single-phase induction motor which is coupled to a resistive or inductive load. Speed control induction motor drives are more prominent nowadays because of certain notable advantages such as high efficiency, simplicity, extreme ruggedness, significant power factor, and no starting torque constraint [1]. Applications of induction motor is in wide areas covering from HVAC (Heating, Ventilation, and Air Conditioning) system, electric vehicles with automotive control, industrial drives including motion control, robotics etc. Thus, requirement of variable - speed drive providing optimal speed control for certain targeted industry is the most important factor. The proposed controller is designed to give the required speed with the minimal possible harmonics in its output.