Over current protection relay using PIC microcontroller / Zoolnasr Bini Abu Harun

Project paper (Bachelor of Electrical Engineering (Power system)) -- Universiti Malaysia Pahang - 2008

Power system protection is the most important requirement before the power system is put into operation. Electrical energy have caused dangers both human and machines. Protection system is mostly controlled by the protection relay. It is the brain of the protection system that monitors input from it sensor as current transformer signals the circuit breaker to open high voltage/current circuits. Over current protection is widely applied at all voltage levels to protect lines, transformer, generators, and motors. Power system protection can be implemented at various stages and various types of protection devices. Industrial operation requires continuous stable power for its operation. The over current relay will serve the purpose on the other hand to protect the system. This project will attempt to design and fabricate over current protection relay using PIC micro controller. The PIC micro controller will cause the circuit breaker to trip when the current from load current reaches the setting value in the PIC micro controller. In order to design it, first the load current need to measure in order to monitor it using current sensor including testing the fault (over current) and when such condition arise, it will isolate in the shortest time possible without harming the any other electrical devices. It will also including in developing the algorithm for instantaneous over current relay and IDMT (Inverse Definite Minimum Time) relay for the circuit breaker to trip. In this project, PIC microcontroller will be used to control and operate the tripping coil in circuit breaker.