摘要
随着风电并网容量的不断增加,风电场参与系统的频率控制是未来发展的必然趋势。了解和掌握并网风电场频率控制特性对于保证系统的频率稳定性具有重要意义。风电场并网的频率控制与传统发电机组有所不同,风电场出力受风速影响具有一定的随机性和波动性。根据风力发电机组出力模型,提出了基于风速变化的风电场下垂控制系数概率模型。利用半不变量的可加性,运算得出随机变量的数字特征,通过Gram-Charlie级数展开的方法计算其概率密度函数。通过对并网IEEE-14节点系统进行仿真计算,结果表明采用下垂控制系数概率模型能够反映其随机变化特性,风电场调频能力受风电场随机出力的影响,验证了概率模型的正确性,为风电场参与系统频率控制提供了一定的理论依据。
Along with the ever-increased grid-connected wind farm capacities, it is an inexorable trend for wind farms to participate the frequency control of power grid, so it is significant for ensuring power grid frequency stability to understand and master the frequency control characteristic of wind farm. The frequency control of grid-connected wind farm is different from that of traditional generating sets, due to the influence of wind speed there is a certain randomness and fluctuation in the wind farm output. According to the output model of wind power generating sets a wind speed variation based probabilistic model of droop control coefficient for wind farm is proposed. Utilizing the additivity of cumulant, through the numerical characteristics of random variables are obtained by operation and by means of Gram-Charlie series expansion the probability density function of random variables is calculated. Through the simulation of grid-connected IEEE 14-bus system, simulation results show that that using the probabilistic model of the droop control coefficient the random variation characteristics of the simulated system can be reflected, and the fxequency regulation ability of wind farm is influenced by random output of wind farm, thus the correctness of the proposed probabilistic model of droop control coefficient is validated, and it offers a certain theoretical basis for wind farm participating power grid frequency regulation.
出处
《电网技术》
EI
CSCD
北大核心
2014年第12期3431-3435,共5页
Power System Technology
基金
输配电装备及系统安全与新技术国家重点实验室自主研究项目(2007DA10512712205)的资助
