电力系统故障计算中多回零序互感线路模型

为处理大规模电力系统中同杆并架线路上任意点、多重故障的计算问题,基于线路实际架设的地理信息反映其实际互感参数,将线路的零序自阻抗与回路间的零序互阻抗以故障处新增节点为界按照线路长度与互感区域长度进行分解,形成完整、准确的节点导纳矩阵,从而建立故障时多回零序互感线路的序分量与相分量模型。利用该模型开发了可处理多回平行线路内部任意故障的计算软件,并对包含4回平行线路6对零序互感的某实际电网进行了复杂故障计算,其结果经EMTP检验是正确的。所研制的故障计算软件已在广东电网投入实际应用。

Study on model for multi-circuit lines with zero-sequence mutual impedances in power system fault calculation

To meet the requirement of the simultaneous fault calculation of the parallel transmission lines on the same pole for large power system, the sequence-component and phase-component node-admittance-matrix model of the multi-circuit lines with zero-sequence mutual impedances was proposed, which is satisfactory enough to calculate arbitrary complex faults even if the fault location extends into the inside of coupling lines. Based on the geography information of the lines, in the case of decomposing self-impedances and mutual-impedances according to the respective universal rules, the procedure of the node zero-sequence admittance matrix was demonstrated. The software of fault calculation was developed by using the model and the computation sample of calculating the simultaneous faults for 4-circuit coupling lines with 6-pair mutual zero-sequence impedances was demonstrated. The simulation results with EMTP show that the model is valid. The developed software is put into service in Guangdong power grid.