Security risk assessment using fast probabilistic power flow considering static power-frequency characteristics of power systems

• We proposed a security risk assessment scheme of fast probabilistic power flow.
• Static power-frequency characteristics is considered in fast decoupled power flow.
• Probability distribution of frequency can be obtained by this scheme.
• The computing speed of the scheme is enhanced compared to conventional method.

Large scale blackouts in the world have aroused the study of security risk assessment (SRA) urgently. SRA difficulties brought about by uncertainties can be solved by probabilistic power flow (PPF). Conventional methods usually focus on the probabilistic density function (PDF) and the cumulative distribution function (CDF) of node voltages and branch flows only. A SRA scheme of power system using fast PPF is proposed in this paper. The scheme took static power-frequency characteristics (SPFCs) into account, and fast decoupled power flow (FDPF) was used to solve PPF. Besides node voltage and branch flows, the scheme can obtain the PDF and CDF of frequency. The computing speed of the proposed scheme considering wind power multi-scenarios is enhanced compared to conventional method. SRA indices are introduced to evaluate the power system quantitatively. The examples on the IEEE RTS-24 system demonstrate the feasibility, rapidity and validity of the proposed scheme.