The demands for massive renewable energy integration, passive network power supply, and global energy interconnection have all gradually increased, posing new challenges for high voltage direct current(HVDC) power tra...The demands for massive renewable energy integration, passive network power supply, and global energy interconnection have all gradually increased, posing new challenges for high voltage direct current(HVDC) power transmission systems, including more complex topology and increased diversity of bipolar HVDC transmission. This study proposes that these two factors have led to new requirements for HVDC control strategies. Moreover, due to the diverse applications of HVDC transmission technology, each station in the system has different requirements. Furthermore, the topology of the AC-DC converter is being continuously developed, revealing a trend towards hybrid converter stations.展开更多
针对多端柔性直流输电的下垂控制方式,研究其工作特性和控制原理,推导其小信号模型,得到基于下垂控制的多端柔性直流输电系统(Voltage Soured Converter based Multi-Terminal Direct Current,VSC-MTDC)小信号模型。在此基础上推导出下...针对多端柔性直流输电的下垂控制方式,研究其工作特性和控制原理,推导其小信号模型,得到基于下垂控制的多端柔性直流输电系统(Voltage Soured Converter based Multi-Terminal Direct Current,VSC-MTDC)小信号模型。在此基础上推导出下垂控制下换流站对交流系统的影响机理,并得到相关结论。最后在一个基于两区四机的三端直流网络系统中证明了文中模型及结论的正确性,即下垂控制对振荡传递的双向性,并得到下垂系数对系统稳定的影响机理。接着使用粒子群算法求解最优的下垂系数,对比仿真结果证明了其可行性和优越性。仿真结果还显示直流系统对低频振荡的隔离性,通过直流系统引起的受迫振荡幅度较小。展开更多
Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operati...Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operation of the AC/DC interconnected grid.This paper first summarizes the medium and low voltage DC distribution system schemes and plans put forward by many countries,and then elaborate status of under-construction medium and low voltage DC distribution system project cases in China.Based on these project cases,this paper analyzes key issues involved in the medium and low voltage DC distribution system topologies,equipment,operation control technologies and DC fault protections,in order to provide theoretical and technical reference for future medium and low voltage DC distribution system-related projects.Finally,this paper combines a current China research status to summarize and give a prediction about the future research direction of medium and low voltage DC distribution system,which can provide reference for the research of medium and low voltage DC distribution system.展开更多
基金supported by the State Grid Science & Technology Project (GEIGC-E-[2018]026)
文摘The demands for massive renewable energy integration, passive network power supply, and global energy interconnection have all gradually increased, posing new challenges for high voltage direct current(HVDC) power transmission systems, including more complex topology and increased diversity of bipolar HVDC transmission. This study proposes that these two factors have led to new requirements for HVDC control strategies. Moreover, due to the diverse applications of HVDC transmission technology, each station in the system has different requirements. Furthermore, the topology of the AC-DC converter is being continuously developed, revealing a trend towards hybrid converter stations.
文摘针对多端柔性直流输电的下垂控制方式,研究其工作特性和控制原理,推导其小信号模型,得到基于下垂控制的多端柔性直流输电系统(Voltage Soured Converter based Multi-Terminal Direct Current,VSC-MTDC)小信号模型。在此基础上推导出下垂控制下换流站对交流系统的影响机理,并得到相关结论。最后在一个基于两区四机的三端直流网络系统中证明了文中模型及结论的正确性,即下垂控制对振荡传递的双向性,并得到下垂系数对系统稳定的影响机理。接着使用粒子群算法求解最优的下垂系数,对比仿真结果证明了其可行性和优越性。仿真结果还显示直流系统对低频振荡的隔离性,通过直流系统引起的受迫振荡幅度较小。
基金supported by the National Key Rese arch and Development Program of China(2018YFB0904100)Science and Technology Project of State Grid(SGHB0000KXJS1800685)
文摘Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operation of the AC/DC interconnected grid.This paper first summarizes the medium and low voltage DC distribution system schemes and plans put forward by many countries,and then elaborate status of under-construction medium and low voltage DC distribution system project cases in China.Based on these project cases,this paper analyzes key issues involved in the medium and low voltage DC distribution system topologies,equipment,operation control technologies and DC fault protections,in order to provide theoretical and technical reference for future medium and low voltage DC distribution system-related projects.Finally,this paper combines a current China research status to summarize and give a prediction about the future research direction of medium and low voltage DC distribution system,which can provide reference for the research of medium and low voltage DC distribution system.
