A wind farm consists of a large number of small wind turbine generators (WTGs) whilst a thermal power plant consists of a small number of large generators. To maintain high quality and high reliability of electrical energy, the wind farm should have the same performance as the thermal power plant in the transient state as well as in the steady state. The wind farm shows similar performance to the conventional power plant in the steady state due to the advanced control technologies. However, it shows quite different characteristics during fault conditions in a grid or at an inter-tie. This gives significant effects on both the operation of a wind farm and the power system stability. This paper describes an analysis of response of a wind farm during grid/inter-tie fault conditions. During fault conditions, each WTG might produce different frequencies in the voltage. These result in the non-fundamental frequencies in the voltage and the current of a point of common coupling, which is called by "beats". This phenomenon requires careful attention on control technologies of a WTG to improve the characteristics in the transient state such as a fault ride-through requirement. Moreover, it may cause difficulties in protection relays of a wind farm. The response of a wind farm for various fault and wind conditions of each WTG was analyzed using a PSCAD/EMTDC simulator.