摘要
由于模块化多电平换流器(modular multilevel converter,MMC)具有较好的控制特性且应用逐步成熟,其不仅应用于高压直流输电领域,在智能配电领域也具有广泛的应用。保障换流器在直流双极短路故障下不闭锁运行且实现故障快速自愈,成为了当前智能配电网柔性一次设备领域的研究热点。首先分析了采用全桥子模块(full bridge sub⁃module,FBSM)的MMC直流双极短路故障机理,随后提出了包含零电压故障穿越控制和直流电流控制的直流双极短路无闭锁故障穿越控制策略。故障发生后启动零电压故障穿越控制可抑制子模块电容放电,且使直流侧电流出现过零点便于直流断路器切断故障电流,在重新建立直流侧电压之后采用直流电流控制可线性抬升功率至故障恢复,实现换流设备无闭锁故障穿越及快速自愈。最后基于PSCAD/EMTDC仿真软件搭建了双端FBSM⁃MMC模型,验证了所提故障穿越策略的有效性。
Because the modular multilevel converter(MMC)has good control characteristics and mature applica⁃tion,it is not only used in the field of HVDC transmission,but also widely used in the field of intelligent distribution.It has become a research focus in the field of flexible primary equipment of intelligent distribution network to ensure the unlocked operation of converter under DC bipolar short circuit fault and to realize rapid self⁃recovery of fault.Firstly,the DC bipolar short circuit fault mechanism of MMC with full bridge sub⁃module(FBSM)was analyzed,and then a DC bipolar short circuit non⁃locking fault ride⁃through control strategy including zero voltage fault ride⁃through control and DC current control was proposed.Starting the zero voltage fault ride⁃through control after the fault occurs can restrain the capacitance discharge of the sub⁃module,and make the DC side current cross zero to fa⁃cilitate the DC circuit breaker to cut off the fault current.After the DC side voltage was re⁃established,the DC cur⁃rent control can be used to linearly lift the power to the fault recovery,so as to realize the non⁃locking fault ride⁃through and fast self⁃recovery of the converter equipment.Finally,a double⁃ended FBSM⁃MMC model was built based on PSCAD/EMTDC simulation software to verify the effectiveness of the proposed fault ride⁃through strategy.
作者
高泽盟
李卫国
杨洪达
周银平
陈艳
GAO Zemeng;LI Weiguo;YANG Hongda;ZHOU Yinping;CHEN Yan(School of Electrical and Electronic Engineering,North China Electric Power University,Beijing 102206,China)
出处
《高压电器》
CAS
CSCD
北大核心
2020年第6期274-281,共8页
High Voltage Apparatus
基金
国家重点研发计划(2017YFB0903100)
国家电网公司科技项目(521104170043)。
关键词
智能配电网
全桥子模块
双极短路故障
故障穿越
无闭锁控制
intelligent distribution network
full bridge sub⁃module
bipolar short circuit fault
fault ride⁃through
non⁃locking control
