Abstract−To avoid undesirable disconnection of healthy wind generators (WGs) or a wind power plant, a WG protection relay should discriminate among faults, so that it can operate instantaneously for WG, connected feeder or connection bus faults, it can operate after a. Abstract−To avoid undesirable disconnection of healthy wind generators (WGs) or a wind power plant, a WG protection relay should discriminate among faults, so that it can operate instantaneously for WG, connected feeder or connection bus faults, it can operate after a. In this paper, the performance of classical protection functions of two commercial relays (denoted as A and B) are investigated. The relays are tested in a Hardware-In-the-Loop environment and the strengths and weaknesses of these functions are determined. This report covers the engineering considerations for the design of the protection systems intended to protect. Switching devices that control and protect electrical systems in wind turbines, relays are essential components that monitor electrical parameters and trigger appropriate responses when abnormal conditions occur. These specialized switches serve as crucial safety mechanisms that isolate circuits. 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 report includes protection of generator step up transformers, collector system feeders.