Fault Detection of Induction Motor by Using PLC

Protection of induction motor (IM) against likely problems, such as overvoltage, overcurrent, overload, over temperature, and under voltage, occurring in the course of its operation is very important, as it is used in industry as an actuator. IMs can be protected using some components, such as timers, contactors, voltage, and current relays. This method is known as the classical method that is very common and involves mechanical dynamic parts. Computer and programmable integrated circuit (PIC) based protection methods have eliminated many mechanical components. The computer-based protection method requires an analog-to-digital conversion (ADC) card, and the PIC-based protection method does not visualize the electrical parameters measured. In this study, for Induction Motors, a new protection method which is based on a programmable logic controller (PLC) has been introduced. In this method, all contactors, timers, relays, and the conversion card are eliminated. Moreover, the voltages, the cur- rents, the speed, and the temperature values of the motor, and the problems occurred in thesystem, are monitored and alert messages are shown on the computer desktop. Experimental results show that the PLC-based protection method developed costs less, provides higher accuracy as well as riskless and optical environment compared with the classical, the computer, and the PIC-based protection systems.