柔性直流配网极间故障控制保护策略与主设备参数配合研究  

Research on control and protection strategy of MMC based DC distribution grid with interpoles fault

作　　者：秦红霞[1] 孙刚[1] 时伯年[1] 邢晓刚[1] 赵宇明 

机构地区：[1]北京四方继保自动化股份有限公司,北京100085 [2]深圳供电局电力技术研究中心,广东深圳518048

出　　处：《电力系统保护与控制》2016年第21期150-156,共7页Power System Protection and Control

基　　金：国家863课题"紧凑化多端柔性直流配电网控制保护关键技术"(2015AA050103)~~

摘　　要：直流配电网在改善供电可靠性和电能质量、实现分布式电源无扰并网以及城市直流负荷接入等方面,相比交流配网有较大优势。然而直流线路具有故障电流上升速度快、峰值大的特点,极易损坏换流器件及设备绝缘,因此,对直流线路的故障处理提出了较高的要求。基于MMC的柔性直流配电网可以通过接地方式的设计实现直流线路单极故障穿越,而危害更大的极间短路故障尚无很好的处理方法。以背靠背典型两端直流配电网为例,分析了直流线路极间短路故障时的暂态特性及其对交流系统、换流器及直流侧的影响。分析了极间故障时的控制保护策略及其与主要设备参数的配合关系。在电磁暂态仿真软件PSCAD/EMTDC下进行了直流线路极间短路故障的仿真研究,验证了该控制保护配置与主设备参数配合策略的正确性。The DC distribution network has great advantages on improving the reliability, power quality, and accessing the distributed power and DC load. However, when a fault occurs, the DC current will rise fast and have great peak value, and it may damage the converter and insulation equipment. So, the DC line fault handing strategy is strictly required. MMC based DC distribution network can achieve line-ground fault crossing via designing a proper grounding method, but there is still no method to handle the line-line fault. In this paper, the transient characteristics of line-line fault and its impact on AC and DC system is studied in a back to back DC distribution network. A line-line fault control and protection strategy is proposed and its cooperation with main equipment parameters is researched. Simulation is conducted on PSCAD/EMTDC, and the results verify the correctness of control, protection and cooperation method.

关 键 词：柔性直流配电网 保护配置 直流线路 极间故障 

分 类 号：TM721.1[电气工程—电力系统及自动化]