适用于多端柔性直流输电系统的通用控制策略

General Control Strategy for VSC-based Multi-terminal DC Systems

随着柔性直流输电技术的不断发展与成熟,多个换流站并联组成的多端柔性直流输电系统成为必然趋势,而换流站数量的不断增多,对多端控制策略提出了更大的挑战。在此背景下,文中提出了一种适应于多端柔性直流输电系统的通用控制策略,其通过权衡系数实现了定直流电压控制与定有功功率控制的灵活切换,通过合理选择权衡系数的计算函数可模拟传统的多端控制策略,并能设计出新型的多端控制策略。最后,在MATLAB/Simulink下搭建了五端柔性直流输电系统进行多个仿真,验证了通用控制策略的正确性与可行性。

With the steady development and maturity in flexible high voltage direct current（ HVDC） technology, the voltage source converter based multi-terminal high voltage direct current（ VSC-MTDC） system with more converter stations has become an inevitable tendency. And the increase of converter stations is posing greater challenges to the multi-terminal control strategy. In this background,this paper proposes a general control strategy for the VSC-MTDC system, with which flexible switching between DC voltage control and active power control can be realized using the weighing coefficient. By rationally choosing the function for calculating the weighing coefficient, the conventional multi-terminal control strategy can be simulated. And a new multi-terminal control strategy can also be designed. A typical five-terminal VSC-MTDC system based on MATLAB/Simulink is built for simulation verification. Simulation results show the correctness and feasibility of the proposed general control strategy.