Numerical Relay-Based Protection System for Induction Motor

Abstract

 The electric motors are used in various industrial applications. 85 percent of the installed capacity of the industrial driving systems is three phase induction motors, which can be subjected to either internal or external faults or both. So, the protection of these three phase induction motors is necessary for well-grounded operation of loads. Protection relays has evolved from single function electromechanical relays to static relays and finally to numerical or digital relays, which has the advantage of less wiring and panel space. The creation of over-current relay model is done using MATLAB/Simulink software. The faults are created intentionally and the current and voltage waveforms are being observed. The current data from the simulation during normal and fault conditions and the temperature are fed as fuzzifier input. The rule is framed by applying knowledge base and it is incorporated to Mamdani fuzzy logic controller for carrying out fuzzification. The defuzzified output is verified for different values of current and temperature which classifies the severity of the fault. The hardware prototype is made achievable using arduino. Three phase supply is fed to the induction motor via relay and sensors. Sensor data’s are read using arduino and the data’s are analyzed using fuzzy logic incorporated in controller and the control signal is fed to the relay based on the severity of fault