许士锦,王毅,景世良,刘婧妍.基于VSC的多端直流环网系统故障分析与定位研究*[J].电测与仪表,2017,54(16):. Xu Shijin,Wang yi,Jing Shiliang,Liu Jingyan.DC side short-circuit fault analysis and location of multi-terminalDC ring system based on VSC[J].Electrical Measurement & Instrumentation,2017,54(16):.
基于VSC的多端直流环网系统故障分析与定位研究*
DC side short-circuit fault analysis and location of multi-terminalDC ring system based on VSC
Compared with the two-terminal DC system, the multi-terminal DC ring system is more reliable and flexible. However, the multi-terminal DC ring system brings more challenges in terms of DC fault analysis and isolation due to the increase of the fault current loops. This paper firstly provides background on the topology and control method of the DC grid, analysis of the fault characteristics of the DC bus and line, and deductions on the mathematical expressions of fault current and voltage. According to the above analysis and with the use of various equipment (current limiting inductor, DC breaker, and DC direction switch), this paper investigates a new fault location and protection strategy based on the fault feather di/dt without using communication between converters. Finally, a three-terminal structure of DC ring network simulation model is established in Matlab/Simulink. The simulation results show that the proposed strategy can quickly identify and isolate fault and ensure the rapid recovery of multi-terminal DC ring system after fault.
