The report provides engineering details covering possible wind farm electrical layouts, equipment ratings, system grounding, transformer connections and characteristics, harmonics and sub-harmonics analysis, voltage and frequency ride-through requirements, and protective relay. The report provides engineering details covering possible wind farm electrical layouts, equipment ratings, system grounding, transformer connections and characteristics, harmonics and sub-harmonics analysis, voltage and frequency ride-through requirements, and protective relay. Working group C25 was given the assignment to write a report to provide guidance on present relay protection and coordination practices at Wind-powered Electricity generating Plants (WEP). This report covers the engineering considerations for the design of the protection systems intended to protect. First, the amplitude and attenuation characteristics of short circuit current in different types of wind turbines are analyzed, as well as the contributing factors to short-circuit current in wind farms. The relays are tested in a Hardware-In-the-Loop environment and the strengths and weaknesses of these functions are determined. The results shown in this paper can be. Understanding Relay Protection in Wind Power Systems: Relay protection in wind power systems serves the purpose of detecting and isolating faults that may occur within the system. These faults include electrical faults such as overcurrent, overvoltage, or short circuits, as well as mechanical. Abstract—A wind electric plant (WEP) is made of many wind turbine generators spread over a large area and includes many subsystems that need to be protected. It is important to ensure that all the subsystems are well protected and coordinated to maximize the reliability (security and dependability).