Phase Current Ratio Based Protection Scheme for Grid Connected Renewable System

Abstract

Increased penetration of converter-interfaced renewable plants improves the current power system's resiliency. The integration of renewable plants also minimises line losses, ensuring the power supply's reliability. During a fault, the PV plant's control mechanism, which complies with grid standards, modulates the current and voltage signals dramatically. As a result, traditional protection relays are unable to give the circuit breaker a trip signal. In this article the concerns with the conventional protection system during the aforementioned circumstance are investigated and a new protection technique is devised for discriminating the internal and external fault by employing both ends current data by calculating the Phase Current Ratio (PCR). Taking consideration of the relay's reliability, sensitivity, dependability and security, threshold region is set. The proposed technique's effectiveness is demonstrated using a 100 kW solar PV array coupled to $a$ 25 kV, grid system at 50 Hz having transmission line of 50 km in software MATLAB/SIMULINK. Different shunt faults are tested and the results proves the validity and authenticity of the suggested relaying scheme in the identification of the internal fault and external fault accurately.