计及相关性和谐波损耗的配电网极限线损计算模型

Calculation model of distribution network limit line loss considering correlation and harmonic loss

针对大规模新能源接入、负荷相关性以及系统不确定谐波影响配电网的极限线损准确计算的问题。为此文中构建一种计及相关性和谐波损耗的配电网极限线损计算模型。建立分布式电源、电动汽车出力的半不变量模型;利用改进的Nataf变换处理负荷出力的相关性,并建立考虑相关性的负荷半不变量模型,分析线路和变压器的损耗随谐波含有率变化情况,并采用指数拟合建立相应的关联模型,通过概率潮流模型求解各状态变量的半不变量,利用Cornish-Fisher级数拟合状态变量的概率分布,进而求取配电网的极限线损,对富含新能源的IEEE 34节点系统进行分析,计算结果验证了模型的准确性。

Aiming at the accurate calculation of limit line loss of distribution network affected by large-scale new energy access,load correlation and system uncertain harmonics,a calculation model of distribution network limit line loss considering correlation and harmonic loss is constructed in this paper.Firstly,the semi-invariant model of DG and EV output is established.Secondly,the improved Nataf transform is used to deal with the correlation of load output,and the load semi-invariant model considering the correlation is established.Then,the variation of line and transformer losses with harmonic content is analyzed,and the corresponding correlation model is established by exponential fitting.The semi-invariants of the state variables are solved by the probabilistic power flow model,and the probability distribution of the state variables is fitted by the Cornish-Fisher,and then,the limit line loss of the distribution network is obtained.Finally,the IEEE 34-bus system with new energy is analyzed,and the calculation results verify the accuracy of the proposed model.