应用于大规模新能源并网的MMC-MTDC双因子自适应下垂控制策略

MMC-MTDC Dual Factor Adaptive Droop Control Strategy for Large-scale Renewable Energy Integration

该文提出一种应用于大规模新能源并网的多端柔性直流输电系统双因子自适应下垂控制策略。针对传统下垂控制电压质量低、功率分配特性差等问题,由本地电气量,引入线路阻抗影响因子、功率影响因子,使换流站P-V特性曲线向最优功率分配方向逼近,并给出参数整定原则及逼近效果衰弱证明。在PSCAD/EMTDC中建立模拟风电场应用的四端柔性直流输电系统仿真模型,算例分析和稳暂态仿真结果表明,所提策略可根据运行工况,灵活调整下垂系数,在提高直流电压质量的同时,减少线路损耗。

In this paper, a dual factor adaptive droop control strategy for multi-terminal high voltage DC transmission system for large-scale renewable energy integration was proposed. In order to solve the problems of low voltage quality and poor power distribution characteristic in traditional voltage droop control strategy, the influence factors of power and line impedance were introduced to make the P-V characteristic curve of GSC approach to the optimal power distribution direction. The principle of parameter setting and the decay proof of the approximation effect were given. Finally, a four terminal HVDC simulation model for wind farm application was established in PSCAD/EMTDC. Example analysis and simulation results of both steady and transient states show that the MTDC system based on the adaptive droop control strategy can adjust the droop coefficients flexibly according to the operation conditions, and has the advantages of high voltage quality and low line loss.