VSC-HVDC风电并网的自抗扰无源控制策略

摘要

针对风电并网的轻型高压直流（VSC-HVDC）输电系统的变流器具有非线性强耦合的特点，单一的控制策略难以满足并网的需求。首先将VSC-HVDC的换流站模型等效成一个具有耗散性质的无源系统，采用端口受控耗散哈密顿系统（PCHD）模型，设计了一种基于互联与阻尼配置的无源控制器来追踪参考电流，同时，为增强系统的鲁棒性，采用自抗扰控制来确定相应的外环电流参考值，最终实现风电的可靠并网。仿真结果表明了自抗扰无源控制为基于VSC-HVDC的风电并网控制提供了一种新的解决方案。%The nonlinear strong coupling characteristics of converter in VSC-HVDC transmission system make the single control strategy difficult to meet the needs of the grid. The proposed scheme makes the VSC-HVDC converter station model equivalent to a dissipative passive system. By choosing the Port-Controlled Hamilton with Dissipation (PCHD) model, the paper proposes a new passive control strategy of Voltage Sourced Converter based on interconnection and damping configuration to trace reference currents. To enhance the system robustness, auto-disturbances-rejection control is used to determine the current reference value, and finally the reliable grid connection of wind farms is realized. The simulation results show that the passive controller provides a novel high performance control solution to VSC-HVDC systems for grid connection of wind farms.