风电场并网用VSC-HVDC的无差拍解耦控制策略

Deadbeat Decoupling Control of VSC-HVDC Systems for Grid Connection of Wind Farms

阐述了利用电压源换流器高压直流输电(VSC-HVDC)用于风电场并网的趋势,给出该方式的基本拓扑结构并建立了VSC-HVDC换流站的通用动态数学模型,提出了一种新的适用于VSC-HVDC系统的无差拍解耦控制策略。该控制策略通过将三相系统在dq坐标系下的解耦特性与abc坐标系下的无差拍控制算法的有机结合,实现了对VSC换流站各控制输出量的解耦控制,不仅具有控制算法简单、计算量小、计算速度快、跟踪精度高和动态响应速度快等优点,而且易于设计。为验证该无差拍解耦控制策略的有效性,应用Matlab/Simulink搭建了一个三电平VSC-HVDC系统用于风电场并网,并进行了系列仿真实验研究。仿真结果表明,所提出的无差拍解耦控制策略为风电场的VSC-HVDC并网控制提供了一种高性能的解决方案。

With the trend to grid-connection of wind farms via VSC-HVDC, this paper develops a universal dynamic model of VSC-HVDC, and proposes a novel deadbeat decoupling control scheme for VSC-HVDC systems to independently regulate the active power, reactive power and dc voltage. The proposed control scheme, is easy for design, consumes less computation time, and yields high tracking accuracy and fast dynamic response. To testify the validity of the proposed control scheme, a case of two-terminal three-level VSC-HVDC system for grid connection of wind farms is developed in Matlab/Simulink. Simulation results show that the proposed control scheme provides a novel high performance control solution to VSC-HVDC systems for grid connection of wind farms.