摘要
为解决传统配电网保护在不借助通信技术的情况下,很难满足微电网线路保护的复杂要求,提出了一种基于负荷阻抗的反时限低阻抗保护(inverse-time low-impedance,ITLI)方案。在微电网结构及故障特点的基础上,类比传统反时限过电流保护,对新型保护的原理、反时限动作特性、配合及整定方法进行研究,给出保护的特点及配置方法。分析过渡电阻对反时限低阻抗保护的影响,并提出低电压加速和配合加速2种改进方法。ITLI保护方案无需借助通信技术,不仅不受微电源控制方式影响,而且适用于微电网并网与孤岛2种运行状态。利用PSCAD/EMTDC建立微网模型,仿真结果表明,ITLI保护方案在不同运行方式下均具有良好的动作特性,并具备较好的抗过渡电阻能力。
To solve the problem that the conventional distribution-network protections can hardly satisfy the requirements of microgrid without the aid of corrlmunication technology, this paper proposed an low-impedance （ITLI） protection scheme based impedance. Compared with the traditional Inverse-time on the load inverse-time overcurrent protection, the protection principle, operating characteristics, coordinative method and calculation of setting value of the new protection scheme were extensively investigated based on the structure and fault conditions of microgrids. And the configuration and properties of ITLI were also provided as a reference for the application. Analysis of the impact of fault impedance on ITLI was conducted, and the relevant improvement containing low-voltage acceleration and coordinative acceleration were presented. Independent of communication systems, ITLI protection is immune from the control methods of varied distributed generators, and can meet protection requirement in all operational conditions. A microgrid model was established in PSCAD/EMTDC and the ITLI protection has good performance under different fault conditions and high resistance to fault resistor.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2014年第1期105-114,共10页
Proceedings of the CSEE
关键词
微电网
反时限低阻抗保护
分布式电源
过渡电
阻
保护加速
microgrids
inverse-time low-impedanceprotection
distributed generation
fault impedance
protectionacceleration
