基于PSS/E的柔性直流输电系统仿真计算研究

Simulation and Study on VSC-HVDC Transmission System Based on PSS/E

柔性直流输电系统作为新一代直流输电技术,其控制策略及暂态过程复杂,仿真计算模型一直处于不完善的状态。以大连柔性直流输电工程为例,采用基于PSS/E模型自定义功能开发的新型柔性直流输电模型,分析柔性直流输电系统的运行特点及其对传统电网的影响,探讨直流电压裕度控制、直流电压下垂控制、紧急有功功率提升/反转控制等的适用场合,提出了柔性直流有功功率支援应在两端换流站交流母线电压恢复正常水平后启动,及有功功率指令值提升速度与定直流电压侧换流站交流母线电压恢复速度相适应的两种改善柔性直流输电有功功率支援暂态过程的控制方法。

As a new generation of VSC-HVDC Transmission technology, the control strategy and transient process of VSC-HVDC transmission system is more complicated, and the simulation model is imperfect. Taking VSC- HVDC transmission project of Dalian as an example, based on the new model developed in PSS/E, analyzes the operation characteristics of VSC-HVDC transmission system and the influence for the grid. The applicable occasions of DC voltage margin control, DC voltage droop control, emergency power support or reversal is discussed. Proposed the flexible DC active support should be activated at both ends of the AC bus voltage converter station to restore the normal level and the active command value to enhance the DC converter speed and AC bus voltage recovery speed to adapt to the two kinds of improved flexible DC active support transient process control method.