基于改进复合序网络的混压部分同塔双回线跨电压故障分析

Analysis of Cross-voltage Fault of Mixed-voltage Double-circuit Lines Partially on the Same Tower Based on Improved Composite-sequence Network

混压部分同塔双回线路因其结构特殊,跨电压故障分析更为困难。本文基于改进复合序网络,建立一种针对混压部分同塔双回线的跨电压各类型故障特征的分析方法。首先,建立并简化混压部分同塔双回线路的各序参数模型,在分析各序参数模型并求解其等效模型的基础上,建立线路各序参数的等效模型;其次,针对各类型跨电压故障,依据边界条件,绘制各类型故障的改进复合序网络;然后,由改进复合序网络图求解出故障点电流等故障特征;最后,在PSCAD中构建了220 kV/110 kV混压部分同塔双回输电线路模型,仿真验证了该分析方法的正确性与实用性。

The special construction of mixed-voltage double-circuit lines partially on the same tower leads to the difficulty in the corresponding analysis of cross-voltage fault.In this paper,based on the improved composite-sequence network,an analysis method is proposed to deal with the cross-voltage fault characteristics of mixed-voltage double-circuit lines partially on the same tower.First,each sequence parameter model of mixed-voltage double-circuit lines partially on the same tower is established and simplified.Based on the analysis of each sequence parameter model and the solutions to their equivalent models,the equivalent model diagrams of the sequence parameters of lines are drawn.Second,for each type of cross-voltage fault,according to the boundary conditions of all types of fault,the improved composite-sequence network diagram of all types of fault is drawn.Afterwards,the improved composite-sequence network diagram is used to solve fault characteristics such as current at the fault point.Finally,a model of 220 kV/110 kV mixed-voltage double-circuit lines partially on the same tower is built in PSCAD,and simulation results verify the correctness and practicability of the proposed analysis method.