The Pulse Width Modulation and its Use in Induction Motor Speed Control

PWM (Pulse Width Modulation) is the term used to describe using a digital signal to generate an analogue output signal. This paper is concerned with principles of PWM, PWM Signal Generators and its use in induction motor. At first the principles of PWM and PWM signal generators are discussed. Secondly, a designer's guide to Power MOS Devices for variable speed control of induction motors is analyzed. Lastly, the paper places the emphasis on the simulating of PWM frequency inverter for induction motor. Via the simulation of dynamic process for induction motor, it analyzes the instantaneous characteristics and change law of PWM control technology for induction motor, such as the rotor current, stator current, torque and speed in different PWM input frequency. And the validity of the simulation model is tested and verified via the simulations. The simulation results show that the way through the PWM can be achieved on the induction motor speed modulation.