太阳光辐照度概率分布参数对电网可靠性的影响

摘要：大规模具有出力波动性的光伏机组并网，必然对电网可靠性产生深远影响。针对光伏机组出力的波动性和间歇性特点，在认为太阳光辐照度服从两参数贝塔分布的前提下，提出了使用极大似然法求解太阳光辐照度概率分布参数的思路，并基于Monte Carlo方法模拟了影响光伏机组输出功率的主要因素：实际太阳光辐照度；据此建立了能够反映光伏机组出力随机性的概率模型；并采用分区的方法，在IEEE—RTS79系统不同区域中接入光伏机组，利用Monte Carlo方法对含光伏机组的互联发输电系统进行可靠性评估；结果表明，在确定地点及一定的负荷水平下，接入一定容量的光伏机组对于提升电网可靠性指标有积极贡献；同时算例给出了不同太阳光辐照度概率分布参数对电网可靠性指标的影响，其结果表明，不同贝塔分布参数对电网可靠性参数有较大影响。

Effect of Different Solar Irradiance Parameters on Reliability Evaluation of the Grid

ABSTRACT: Large-Scale volatility photovoltaic grid-connected which will have a profound impact on the reliability of the system. A new method based on maximum likelihood estimation is presented in this paper in which probabilistic distribution of solar irradiance is calculated on the premise of solar irradiance beta distribution, according to volatility and intermittent characteristics of photovoltaic, and simulated the actual solar irradiance which affecting power output of photovoltaic based on Monte Carlo method, then, Established a photovoltaic probability output model which can reflect the randomness output of photovoltaic; and use of the partitioning method, the reliability assessment of an interconnected generation system with photovoltaic connected with IEEE-RTS79 system is performed by Monte Carlo simulation; The results show that there have a contribution on reliability evaluation of the grid when connected on determined location and under a certain load level; also the example show the influence of different parameters of solar irradiation on system reliability indicators and the result show different parameters of beta distribution have a great impact on grid reliability indicators.