In the recent years, as the capacity of grid-connected photovoltaic (PV) power grows rapidly, the substantial increase of research and development work in the area of PV systems have made the PV generations become an effective alternative energy resource that complements other energy sources in hybrid energy systems. However, if the power system is affected by a large disturbance, disconnection of high penetration of PV generation strongly impacts on voltage stability of power systems. This paper presents a emergency control strategy to prevent power system from voltage collapse due to a large penetration of PV generation disconnection.