Application Of Improved Method Of Non-sequential Monte Carlo Simulation To Risk Evaluation Of Grid Operation Modes

The essential operation planning function in a control center is to select secure,reliable and economic operation modes under different operation conditions. However,there often exist several operation modes that all meet the basic operation criteria. Itis necessary to identify the lowest-risk operation mode to assure safe and reliableoperation of the overall system, which is the purpose and tasks for risk evaluation ofgrid operation planning.In this paper, the basic methods of risk evaluation conducted in-depth study,since the issuance of transmission grid network complexity, the evaluation processinvolves a large number of calculations, but the basic methods of risk evaluation gainlow efficiency, so present of "non-sequential Monte Carlo Improvement method" andapplication of it to grid operation planning assess several operation mode and identifythe lowest risk one. Calculation example shows that the method’s variance has fastconvergence speed, a single simulation time is short, and the efficiency is muchhigher than traditional non-sequential Monte Carlo simulation. The power gridplanning risk evaluation model was established based on this method, plaited thecorresponding computer program and gave an example evaluation in the paper. Themain contents include the following:1.First introduce the grid operation planning risk evaluation’s research anddevelopment status at home and abroad, and explain its contents and significance.2.Analysis of two basic methods for risk evaluation in power system——analytical method and Monte Carlo simulation. Comparison of the advantages anddisadvantages of the analytical method and simulation method, and analysis ofmechanism and the defects of traditional non-sequential Monte Carlo method in detail,present of non-sequential Monte Carlo Improvement method by combination of thescattered sampling and analytical judgment.3.Study and discussion of the network topology analysis and power flow foridentification of system problems in-depth.4.Then, the fault model of a variety of components was established based on thisimproved method, establish of integral algorithm flow and Indicators system for gridoperation planning risk evaluation,and preparation of the evaluation process. Finally,this evaluation process applied to the IEEE RTS79system operation planning risk evaluation, two different situations of this standard system were quantitativelyassessed. One case is operation modes with different level of total load during normaloperation, in which evaluation results can provide guidance for short-term mainte-nance program; Another case is operation modes with the same level of total load butdifferent load transfer programs. when it is related to equipment repair or replace, theevaluation results in this case indicate that the computer program can calculate riskindicators of the system for different operation modes and identify the lowest riskoperation mode, as a useful reference to operation control department.