一种标杆光伏组串选取方法及其在故障诊断中的应用

BENCHMARK PV STRING SELECTION METHOD AND ITS APPLICATION IN FAULT DIAGNOSIS

为实现对光伏组串故障的准确、快速诊断,以满足光伏电站数智化运维的需求,同时针对实际运行中的光伏组串基准运行状态难以确定的问题,提出一种基于实际运行数据的基准运行状态下的光伏组串(即标杆光伏组串)选取方法,并将其应用于光伏组串故障诊断中。首先利用多指标综合评价算法选取光伏标杆组串;然后利用标杆光伏组串与其他光伏组串间的输出电压、输出电流的相对误差,基于3σ准则设计了光伏组串故障诊断规则;最后利用某集中式光伏电站中光伏组串的实际运行数据对所提方法的合理性和有效性进行验证。研究结果显示:1)通过与其他光伏组串的输出功率进行对比,验证了所选标杆光伏组串的合理性;2)故障光伏组串所显示出的故障状态与基于所提出的故障诊断规则得到的结果一致,证明了此故障诊断方法的有效性。

In order to achieve accurate and rapid diagnosis of PV string faults,meet the needs of intelligent operation and maintenance of PV power stations,and address the problem of difficulty in determining the benchmark operating state of PV strings in actual operation,this paper proposes a kind of method for selecting PV strings under the benchmark operating state based on actual operating data(i.e.benchmark PV strings),and applies it to PV string fault diagnosis.Firstly,a multi index comprehensive evaluation algorithm is used to select the benchmark PV string.Then,based on the relative error of output voltage and output current between the benchmark PV string and other PV strings,a fault diagnosis rule for PV strings is designed based on the 3σcriterion.Finally,the rationality and effectiveness of the proposed method are verified using actual operating data of PV strings in a centralized PV power station.The research results show that:1)The rationality of the selected benchmark PV string is verified by comparing its output power with other PV strings.2)The fault state displayed by the faulty PV string is consistent with the results obtained based on the proposed fault diagnosis rules,which proves the effectiveness of this fault diagnosis method.