Adequacy Evaluation Of Transmission Systems Using Monte Carlo Simulation And Nonlinear Programming Technology

With the development of the domestic economy,domestic power grid becomes largerand more complex and is entering a new stage: transmission electric power from West to Eastand exchange electric power between South and North and interconnection in the wholecountry , transmission network is playing a more and more important role in the overall powersystem. Meanwhile, as the load increases sharply, the power grid planning lags behind theactual power assumption, the overload of power grid becomes increasingly prominent.and thefailure-rate of the transmission systems increases largely, multi-failure happens occasionally,failure mode becomes more complex, the adequacy evaluation of transmission systemsbecomes urgent and necessary.The adequacy evaluation model and solution of the transmission systems are establishedand realized in the paper. The non-sequential Monte Carlo simulation algorithm is applied tosample failure states of transmission systems so that it can simulate multiple failures,andnetwork topology and its analysis is realized by means of the the storage of the connectionmatrix and breadth first search techniques so that multiple failures and islanding are identifiedefficiently and sampling time of failure states is reduced. The AC power flow is used to judgethe line overload and voltage violation more accurately. Also an optimal load shedding nonlinearprogramming model is established which is solved by primal-dual interior pointalgorithm based on the perturbed-KKT-conditions, which can solve the corrective action ofthe active power and the reactive power.Futhermore, the severe failure states are filtered andsorted through weighting sampling probability of failure states and optimal load sheddingquantity to find out operational risks and weaknesses of transmission systems.The correctness and effectiveness of the proposed method and its sub module have beenverified on the adequacy evaluation of IEEE-RBTS and IEEE-RTS79 systems. Because of itscalculation speed and accuracy,the proposed algorithm have the potential of the large scaletransmission systems.