高电压技术2017，Vol.43Issue(4)：1137-1143,7.DOI:10.13336/j.1003-6520.hve.20170328010
MMC-HVDC停运放电过程分析及放电时间定值整定
Discharge Process Analysis and Discharge Time Setting Method of Modular Multilevel Converter Based HVDC After Shutdown
摘要
Abstract
The DC bus and sub-module should be fully discharged to ensure that the voltage is below the safety threshold after the shutdown process of modular multilevel converter based on HVDC (MMC-HVDC).In view of the limited research on the discharge process,we established a simulation model of MMC-HVDC flexible transmission project in China during the discharge process,and analyzed the discharge characteristics.The mathematical description formula of discharge time and residual voltage was deduced based on the discharge simulation model,and the setting method of discharge time was also proposed.Finally,a designed example was given and the verification tests were conducted at Xiamen HVDC flexible project.The results show that the simulation results are nearly identical to the experimental data,which indicates that the DC bus discharges via the equivalent grounding resistance of potential transformer;and the discharge process of sub-module can be divided into two cases according to different working states of the energy-absorbing source:the capacitor discharges via the control circuit and shunt resistance when the source is working,and the capacitor discharges only by the shunt resistance when the source is turned off.The discharge time setting method has been applied to Xiamen HVDC flexible project,which has ensured the fully discharge of the DC bus and sub-module,thus further confinns the validity of the designed setting method of discharge time.关键词
柔性直流输电/模块化多电平换流器/子模块/直流母线/放电时间/定值整定/取能电源Key words
HVDC flexible/modular multilevel converter/sub-module/DC bus/discharge time/value setting/energy-absorbing source引用本文复制引用
李超,唐志军,郭健生,晁武杰,陈锦山,胡文旺..MMC-HVDC停运放电过程分析及放电时间定值整定[J].高电压技术,2017,43(4):1137-1143,7.基金项目
国家电网公司科技项目(52130415000Z).Project supported by Science and Technology Project of SGCC (52130415000Z). （52130415000Z）
