Risk Assessment And Optimal Dispatch Of Power System Based On Stochastic Load Flow

With the continuous development of the electric power industry,power system is faced with increasingly complex operating environment.Thus,the requirements for dispatch considering operation risk are becoming more and more serious.For the existing optimal dispatch method,there is insufficient consideration of risk factors.Most of them only concerned with the influence of individual uncertainty factors,and lack of comprehensive consideration and analysis on many uncertain factors.This paper study the risk assessment and optimal dispatch method of power system based on various uncertainties,the main work is as follows:1.For wind power fluctuation,unit outage,line fault,load fluctuations and other uncertainties,the characteristics are analyzed and the corresponding mathematical models are established.And for different weather conditions,the real-time correction of line fault probability is carried out,which is closer to the actual operating environment.Based on the theory above,the calculation model of stochastic load flow is derived,and the Gram-Charlier series and Cornish-Fisher series used to fit the distribution function of the random variables are introduced.2.Based on the result of stochastic load flow,the quantitative index is established to measure the operational risk of the system.Through the IEEE-14 system,the difference between two kinds of series is compared,and the operating condition of the system is evaluated,and the weakness of the system is pointed out.By analyzing operation risk and the distribution of voltage and power flow in different scenarios,the importance of considering line fault and weather factors is verified.3.The research above is applied to the optimal dispatch,and a model based on operation risk is formulated with operation risk and generation cost as the objective functions.This model is solved by the multi-objective particle swarm algorithm and the fuzzy set theory.The feasibility and effectiveness of applying stochastic load flow to the optimal dispatch is verified by the static and dynamic optimal dispatch model,and the difference of dispatch schemes is compared with multiple scenarios.The results show that the dispatch schemes can be more accurate with the consideration of the influence of line fault and weather factors,which provides a useful reference for the short-term optimal dispatch.