Protection Coordination Study and Recommendations for a Real Time Operational Wind Farm with Type-1 and Type-4 Wind Turbine Generators

Renewable Energy (RE) is the clean and green energy and it has undergone fast expansions worldwide especially in the last two decades. Wind power generation is gaining popularity across the globe and it poses lot of challenges as well like intermittency in nature, power grid integration, inertia, stability, security, protection issues and transient stability. Comprehensive protection schemes are compulsory to improve network system reliability, transient stability of the network and to ensure Wind Turbine Generators (WTGs) connectivity to the grid under different fault conditions. In this paper, the existing real-time operational wind farm is modelled and simulated in Electrical Transient and Analysis Program (ETAP) software. IEC 60909 standard is followed for load flow calculations and short circuit analysis. Existing Protection schemes are evaluated and relay coordination is undertaken for both Type 1 and Type 4 WTGs. Relay coordination is carried out using Normal Inverse Definite Minimum Time Lag (IDMTL) characteristics for 22 kV feeders, power transformer LV side, HV side and 110 kV Grid side, as per IEC 60255-151:2009 which is the latest standards. Also, a suitable optimal relay setting is recommended for proper sequence of operation and to maintain reliability of the power system networks.