Sensors for Fault Detection and Protection of Induction Motors

Since an induction motor (IM) is commonly used as a drive in industry, it must be protected against common faults such as overvoltage, overcurrent, overload, overtemperature, and undervoltage. Timers, contactors, voltage and current relays, and other components can be used to protect IMs. This method is called the classical method, which is relatively simple and uses mechanical dynamic parts. Computers and programmable integrated circuits (PIC) have replaced most mechanical components. Computer-based protection requires an ADC board. However, electrical parameters measured by PICs cannot be displayed in this method of computer-aided protection. In this work, a programmable logic controller (PLC)-based protection solution for IMs was developed. This method eliminates the need for all contactors, timers, relays, and the conversion card. To alert the operator, a computer monitors the motor’s voltages, currents, and speeds, as well as any problems that have occurred in the system. The PLC-based protection approach developed is less expensive, more accurate, and provides a safer and more visually appealing environment than traditional computer-based and PIC-based systems.