计及分布式新能源不确定性的虚拟电厂调度边界概率分布刻画方法

Probability Distribution of Dispatch Region for a Virtual Power Plant Considering Distributed Renewable Uncertainties

虚拟电厂可聚合分布式新能源参与主网调度,发掘分布式新能源的互动潜能。随着分布式新能源的快速发展,虚拟电厂调度需计及新能源不确定性。虚拟电厂的调度边界准确刻画是确保其安全运行的关键。基于多参数规划理论,提出计及分布式新能源不确定性的虚拟电厂调度边界概率分布刻画方法。所提方法以新能源随机变量为规划参数,研究虚拟电厂关口极限交换功率与新能源功率的分段解析映射,基于全概率原则计算虚拟电厂调度边界的累积分布函数。为减少由于随机变量规模增长造成的繁重计算负担,文中提出基于线路转移分布因子排序的关键随机变量辨识方法,实现虚拟电厂调度边界概率分布的快速刻画,并将所提虚拟电厂调度边界概率分布应用于虚拟电厂-主网协同优化调度。基于IEEE 136节点配网的仿真计算论证了所提方法的有效性和准确性。

A virtual power plant(VPP)can aggregate distributed renewables(DRs)for the transmission-level operation,digging out the interactive potential of DRs.With the rapid growth of DRs,uncertainties of renewable energy should be incorporated into the dispatch of a VPP.A desired characterization of the dispatch region guarantees the safe operation of a VPP.Based on the multi-parametric programming theory,this paper presented a calculation method of the probability distribution of dispatch region for a VPP considering the uncertainty of DRs.By regarding renewable stochastic variables as programming parameters,the presented method explicitly formulated the piecewise affine mapping between renewable power and power exchanges at the point of common coupling.The cumulative distribution function of the dispatch region was further calculated based on the total probability principle.However,the computational burden exponentially increased with the number of stochastic variables in the multi-parametric programming theory.To resolve this issue,this paper presented the identification method of key stochastic variables based on the priority of the power transfer distribution factor matrix.This achieved the fast calculation of the probability distribution of dispatch region for a VPP.The probability distribution of dispatch region was applied to coordination among transmission networks and VPPs.The numerical results in the IEEE 136-bus distribution networks demonstrate the validity and effectiveness of the presented methods.