Microcontroller Based Wye-Delta Starter and Protection Relay for Cage Rotor Induction Motor

In this study, PIC 18F4520 based wye-delta starting and protection relay was designed and manufactured with semiconductor devices for three phase cage rotor induction motors. Protection relay controls the phase absence and phase sequence before motor starting process. Designed relay system performs better than that of other electromechanical starting and protection relays, due to the decrease in the number of electromechanical components, total volume of relay, complexity of system. Furthermore, the use of microcontroller and semiconductor devices makes the new starter and protection relay design more robust and more reliable.