Introduction:

             etaz Systems was approached by a client to design a Feeder Protection Relay for HV Feeders. Our team, with their expertise in architecture, R&D, schematics, BOM and DSP, delivered a solution that met the client’s requirements. The relay was designed for earth faults, short circuiting, over voltage and overload protection. It collects real-time data from CTs and PTs and acts instantaneously to mitigate the fault by sending a cutoff signal to CBs (Inverse Definite Minimum Time and Definite Minimum Time techniques implemented in firmware). The relay communicates to other devices through RS-485 MOD-Bus RTU. It has a number of boards including a Binary Input and MOD Bus(Power Supply), CT Board, Relay Board, and Relay Controller Board. The system architecture design was carried out in accordance with the user requirement document. The relay was designed for harsh and critical interference environment and was tested for its performance. The firmware was developed for ARM4, with internal ADC sampling at 20ksps, FIR LP and HP filter design and half duplex RS485 MOD Bus RTU. The communication interfaces used were 12C, R523, RS485, SAI, and SPI. The project was completed in June 2018 to July 2020 and was delivered on time and within budget.