Performance Analysis & Speed Control of 3 Phase Induction Motor on 8 Bit Controller Platforms Using LabVIEW®

Abstract

Performance analysis & speed control of 3 phase induction motor on 8 bit platform using LabVIEW^® aims to speed control of 3-phase induction motor, microcontroller used for this work is AVR ATmega16. LabVIEW^® provides the remote GUI interface to the system. LabVIEW^® interfaces to the control system with the RS-232 communication link Using NI-VISA. Actually induction motor controlling through microcontroller and PC based GUI leads to the almost complete design of the 3-phase induction motor drive. All components of the system receive the power from one main power supply unit that accepts standard 230V single phase AC supply. Single phase AC input is converted into 3-phase AC with the PWM bridge inverter. 3-phase output voltage and frequency are the functions of PWM signals generated by the microcontroller. Both frequency and voltage are varied but V/f should be constant. Optical Tachometer measures the speed of the rotor shaft. System can be operated in the closed-loop mode with the RPM set-point of rotor shaft. So the speed of the motor can almost independent of varying loads (within some range). Due to the PI Action Algorithm in the microcontroller program, continuously varying loads do not make oscillation in the output speed of motor.

Keywords: AVR Microcontroller, LabVIEW®, NI-VISA, 3-pahse Induction Motor, PWM, Constant V/f, Optical Tachometer, Closed-loop Speed control, RS-232,Virtual Instrumentation.