The Reliability Evaluation Of Photovoltaic Power Plant Based On Markov Chain Monte Carlo Method

With the development of photovoltaic industry,the installed capacity of grid-connected photovoltaic power generation system continues to improve,many large photovoltaic power plants began to build.Due to the time of photovoltaic po wer generation technology in engineering application is relatively short,the technology is not mature enough,the installing phenomenon is serious,the internal fault is common,the ability of photovoltaic power plants remains to be studied can complete i ts intended task.Therefore,it is of great significance to evaluate the operational reliability of large-scale photovoltaic power plants from the point of view of economic value or operation.In this paper,the Markov Method Monte Carlo method is used to evaluate and quantify the operational reliability of photovoltaic power plant.The main work and innovative achievements are as follows:Firstly,the key components of the photovoltaic power station are divided into two state and multi-state components from the angle of modeling,and the reliability model of components is established by analyzing the operation characteristics of different components.Among them,the photovoltaic array in each generation unit as a multi-state component is modeled,in order to avoid the difficulty of the follow-up assessment process,in the premise of certain precision by the number of backward scenario reduction technology of components was simplified.Secondly,The reliability index system of the photovoltaic power plant was defined.For the consideration of power plant capacity,the failure probability,the power losses,there are four indexes in the index system,which contains expected value of available capacity EAC,probability of insufficient capacity PIC,expected value of insufficient capacity EIC,expected value of power loss EPL,and formulas are given.The Markov Method Monte Carlo method was introduced to reliability assessment of photovoltaic power plants,using Gibbs sampling as the sampling method,comparing with the traditional Monte Carlo method,verify the correctness of the method,the superiority,and stability.This method is used to evaluate the reliability of the same structure with different photovoltaic power plants,and to quantify the difference in the reliability of the two structures.Thirdly,based on the time-varying characteristics of component failure rate,the reliability assessment of the whole life cycle of the photovoltaic power station is carried out.The photovoltaic power plant reliability assessment index system not only can make a quantitative assessment of the reliability of photovoltaic power plants,in the photovoltaic power plant investment and construction,power generation forecasting and other aspects are also an important value.In this paper,the reliability index EAC is used to revise the long-term power generation capacity of a photovoltaic power station,and the forecast value of the medium and long term power generation is obtained.