摘要
为有效降低电网换相高压直流(line-commutated converterhighvoltagedirectcurrent,LCC-HVDC)输电系统换相失败的概率,提出串联电压换相变流器(seriesvoltage commutated converter,SVCC)方案。该方案以直接增加换流阀换相电压面积为目标,将级联的全桥子模块变流链接入换流变压器与LCC换流阀交流端口之间,通过灵活控制串联电压对阀组辅助换相。基于全桥子模块的8种工作状态,设计变流链串联电压辅助换相策略及电容电压控制方法;以SVCC临界换相电压为依据,提出子模块电容容值及额定电压的优选方法。PSCAD/EMTDC仿真结果表明,SVCC拓扑能灵活切换子模块变流链的工作状态,所提出电容电压控制效果良好,与仿真结果吻合度高。相比其他方案,SVCC对交流系统电压暂降的电压补偿响应速度快,可显著提高LCC-HVDC防御换相失败的能力。此外,当交流系统故障超出SVCC抑制换相失败范围,SVCC所采取的紧急应对措施降低了变流链内开关器件的电流应力要求,提高了其工程实用性。
In order to effectively reduce the probability of commutation failure of line-commutated converter high voltage direct current(LCC-HVDC)transmission system,a series voltage commutated converter(SVCC)scheme was proposed. Aiming at directly increasing the commutation voltage area of the commutation valve,this program connected the cascade full-bridge sub-module chain into the converter transformer and the AC port of LCC commutation valve and flexibly controlled the series voltage to assist the commutation process. A series voltage assisted commutation strategy and a capacitor voltage control method were designed based on the eight working states of the full-bridge submodule.The preferred method of the sub-module capacitor and its rated voltage was proposed grounded on the SVCC critical commutation voltage. The simulation results of PSCAD/EMTDC show that the SVCC topology can flexibly switch the working states of the submodule and the proposed method of capacitor voltage control is effective,which is in good agreement with the simulation results.Compared with other inverter topology improvements,SVCC can response faster and significantly improve the ability in defensing commutation failure.In addition,when the AC fault exceeds the suppression range of SVCC,the emergency response measures'taken by SVCC can reduce the current stress requirements of the switching devices in the sub-module chain,which enhances the practicability of engineering application.
作者
侯灵犀
魏应冬
张树卿
姜齐荣
韩英铎
HOU Lingxi;WEI Yingdong;ZHANG Shuqing;JIANG Qirong;HAN Yingduo(State Key Laboratory of Control and Simulation of Power System and Generation Equipments(Tsinghua University),Haidian District,Beijing 100084,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2018年第22期6481-6490,共10页
Proceedings of the CSEE
基金
国家重点研发计划(2016YFB0900600)
国家电网公司科技项目(52094017000W)~~
关键词
电网换相高压直流输电
换相失败
全桥子模块
绝缘门极双极性晶体管
电压补偿
line-commutated converter high voltage direct current(LCC-HVDC)
commutationfailure
full-bridge sub-module
insulated gate bipolar transistor(IGBT)
voltage compensation
作者简介
侯灵犀(1994),女,博士研究生,主要研究方向为电力系统稳定与控制,lx_hou@163.com;魏应冬(1979),男,讲师,主要研究方向为柔性交流输配电系统建模与控制、电能质量分析与控制;姜齐荣(1968),男,教授,博士生导师,主要研究方向为电力系统分析与控制、柔性交流输配电系统建模与控制、电能质量分析与控制。
