小电阻接地系统馈线自适应零序电流保护原理及装置实现

发布时间：2018-06-05 08:38

本文选题：小电阻接地系统 + 零序电流　；参考：《电力自动化设备》2017年11期

【摘要】：小电阻接地系统发生多回线同相复杂接地故障时,零序电流幅值相比于单回线接地故障将显著下降,容易导致馈线首端的零序电流保护拒动,进而造成母线接地变压器的零序电流保护越级误动,扩大停电范围。为此,对小电阻接地系统多回线复杂接地故障的故障机理进行分析,推导了多回线与单回线接地故障下馈线零序电流关系;在此基础上,提出了一种自适应馈线零序电流保护方案,即根据母线电压将多回线接地故障的零序电流实时补偿为单回线接地故障的零序电流值,从而确保了常规的保护动作值整定方式和保护配合能够适用于多回线复杂接地故障,并研发了相应的自适应零序保护装置。基于PSCAD/EMTDC和RTDS对保护原理及保护装置的测试结果表明,自适应零序电流保护在多回线复杂接地故障情况下仍具有较高的灵敏性,补偿精度不受过渡电阻、故障位置的影响。所提保护方案只需在原有零序电流保护方案基础上,增加母线电压信息,容易实现,具有经济性和较高的工程应用价值。
[Abstract]:When multiple in-phase complex grounding faults occur in a small resistance grounding system, the amplitude of zero sequence current will decrease significantly compared with that of single circuit grounding fault, which will easily lead to zero sequence current protection at the first end of the feeder. Thus, the zero sequence current protection of the busbar grounding transformer is overrun and the range of power outages is enlarged. Therefore, the fault mechanism of multi-circuit complex grounding fault of small resistance grounding system is analyzed, and the zero-sequence current relation of feeder line under multi-circuit and single-circuit grounding fault is deduced. An adaptive zero-sequence current protection scheme is proposed, in which the zero-sequence current of multi-circuit grounding fault is compensated to zero sequence current value of single-circuit grounding fault according to bus voltage. Thus, the conventional protection operation value setting method and protection coordination can be applied to complex grounding faults of multi-circuit lines, and a corresponding adaptive zero-sequence protection device is developed. The test results based on PSCAD/EMTDC and RTDS show that the adaptive zero-sequence current protection still has high sensitivity in the case of multi-circuit complex grounding fault, and the compensation accuracy is not affected by the transition resistance and fault location. The proposed protection scheme only needs to increase the bus voltage information on the basis of the original zero-sequence current protection scheme, which is easy to realize and has economic and high engineering application value.
【作者单位】：南方电网科学研究院;华南理工大学电力学院;
【基金】：国家自然科学基金资助项目(51477057)~~
【分类号】：TM773;TM862

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