Study On Power System Reliability With Wind Power Integration

In recent years, wind power is showing explosive growth as a clean energy in support of national policies. When wind power penetration is large, the randomness and volatility of wind speed can seriously affect the quality, stability and reliability of grid power, and even lead to power outages, which requires the power system containing wind farm reliability evaluation.This paper analyzes the various features of wind speed sequences, mainly in terms of short-term volatility, continuous timing, frequency domain characteristics, probability distribution and circadian complementary characteristics, which can evaluate wind speed mathematical model. Based on MATLAB software this paper establish and simulate Weibull model and time series model of wind speed sequence. By comparison and analysis, time series model can reflect the continuity of the wind speed at the time, but ignore the impact of time value on wind speed. This article works on preliminary discussion research and proposes a model combination of ARMA based on probability measure transformation theory, as much as possible to retain the characteristics of wind speed sequences.Based on MATLAB software, this paper presents and simulates sequential and non-sequential Monte Carlo algorithm for reliability assessment of IEEE-RTS79 which is a conventional generation and transmission system. For the slow convergence of traditional sampling method, this paper describes two improved sampling method:importance sampling method and average-scattered sampling method, and works on analysis and simulation.Combining with wind speed series model the reliability mathematical model of wind farm has been established, which takes into account the randomness of wind energy, wind turbine failures and other uncertainties. By accessing it to RTS79 power system and based on Monte Carlo algorithm, this paper assesses the influence of wind farms replacement of conventional units, wind power access point, wind power penetration and wind speed factors on the wind power system reliability level, which establishes the theoretical foundation of planning and operation of wind farms.Calculation of wind farm capacity credit is to determine the cost savings obtained by replacing the thermal power plants with wind farms as well as an important basis for determining wind power electricity price, thereby increasing the economic value of wind farms. In this paper, the definition of wind farm capacity credit is based on effective load carrying capability. On the basis of non-sequential Monte Carlo algorithm and secant iteration method, combined with a detailed example this paper analyzes the influence of different network programs on wind farm capacity credit.