Probabilistic dynamic load flow algorithm considering static security risk of the power system

Nowadays, the stable and secure operation of power system has attach more and more attention. The traditional static security analysis is based on deterministic load flow, which cannot reflect the uncertainty of load and the probability of branch outage. In addition, the conventional load flow model does not consider the static power-frequency characteristic of generators and load, which is not in accordance with the real operating condition of power system. In order to provide comprehensive static security risk assessment for the power system, so that the potential dangerous and vulnerable part of power system can be recognized before serious outage happens, a Probabilistic Dynamic Load Flow considering Static Security Risk (PDLF-SSR) algorithm is proposed, in which a new state variable — system frequency is added. And the loss is no longer undertook by balancing generator only but by all generators having speed controllers. In addition, this paper also considers the contingency set of power system by calculating the probability of each contingency happening and then obtaining the PDLF of each contingency. Thus, the overall PDLF considering contingency set can be obtained by combining the full probability theory and PDLF based on cumulants. The algorithm can provide valuable information for power system planning, reliability analysis and static security risk assessment.