电压源型直流输电变流器的直接功率控制研究

摘要

针对风电场并网电压源直流输电系统,在αβ坐标系下VSC-HVDC系统离散化数学模型基础上,结合瞬时功率理论和空间矢量脉冲宽度调制,提出了一种适用于VSC-HVDC系统的新开关表的直接功率控制.其中,风电场侧采用定有功功率和无功功率,电网侧采用定直流电压和无功功率,利用MATLAB/ Simulink搭建相应的仿真模型,通过对有功、无功阶跃突变工况的仿真分析,验证了该方案的有效性和可行性,为风电场并网电压源高压直流输电系统提供了一种可行的控制方案.%According to the grid connected voltage source DC transmission system in wind farm, the discrete mathematical model VSC-HVDC system in reference frame is derived.A novel direct power control strategy in the voltage sourced converter is proposed based on instantaneous power theory and space vector pulse width modulation in the paper.Constant active and reactive power controller is used in the wind farm side, and a constant DC voltage and constant reactive power controller is used in the grid-side.A case of two-terminal VSC-HVDC system for grid connection of wind farms is developed in MATLAB/Simulink.The simulation results show the effectiveness and feasibility of the proposed control methods which provide a viable control solution in voltage sourced converter based high voltage direct current systems for offshore wind farm.