Risk assessment for special protection systems

Special protection systems (SPS) have been widely used to increase the transfer capability of the network by assisting system operators in administering fast corrective actions. Compared with constructing new transmission facilities, SPS can be placed in service relatively quickly and inexpensively. However, increased reliance on SPS results in additional risks to system security. In this paper, based on existing reliability evaluation methods, a generic procedure for risk-based assessment of SPS is proposed. The procedure can help the system operator to identify the risk brought by SPS and to make SPS-related decisions. An illustrative example which uses a generator rejection scheme (GRS) for transient instability is provided.