特高压多端混合直流输电系统的控制策略研究

Research on Control Strategy of Multi-Terminal Hybrid UHVDC Transmission System

以乌东德电站送电广东广西特高压多端直流示范工程为背景,针对混合多端直流运行方式复杂、可靠性要求高的特点,研究了特高压混合多端直流输电系统的控制策略,提出了适用于特高压混合多端直流输电系统的控制模式以及启动/停运方案,实现了混合直流的外特性匹配、两端/三端启动/停运,以及第三端在线投入/退出;同时,提出了各端稳态控制策略和多端协调控制策略,可适应混合多端直流输电系统复杂的运行方式。最后,基于PSCAD/EMTDC的数字仿真结果验证了所述控制策略的有效性,可以保证特高压混合多端直流输电系统可靠稳定运行。

Based on Wudongde multi-terminal UHVDC demonstration project,the control strategy of multi-terminal hybrid UHVDC transmission system is researched to adapt to the characteristics of complex operation and high reliability requirements. The control mode and starting-up/shutting-dow n approach applied to multi-terminal hybrid UHVDC system are proposed,which could realize the matching of external characteristics of hybrid DC,two/three terminal stations starting-up/shutting-dow n,and the third terminal station online inputting/quitting. Also,the steady state control strategy of each terminal and multi-terminal coordinated control strategy are also studied,which could adapt to the complex operation of multi-terminal hybrid HVDC transmission system. Finally,the simulation results based on PSCAD/EMTDC show the validity of proposed control strategy,verifying the reliable and stable operation of multiterminal hybrid UHVDC transmission system.