VSC-HVDC海上风电输电变流器预测电流控制策略研究

RESEARCH OF DIGITAL PREDICTIVE CURRENT CONTROL FOR WIND POWER VSC-HVDC

针对目前VSC-HVDC海上风电输电变流器电流暂态响应慢,存在稳态误差等不足,提出一种新的数字预测电流控制方法,基于电压空间矢量调制得到控制开关信号,使三相输入电流快速跟踪三相输入电压的相位,快速消除系统静差和离散误差,变流器按照单位功率因数运行。利用该方法可在当前采样时刻快速准确地预测下一采样时刻的参考电流值,同时结合品质方程确定下一采样时刻的最优输出端参考电压矢量。结合500kVA实验样机设计,经Matlab仿真结果验证了该控制策略的可行性和有效性。

A new predictive current control （PCC） method was proposed for the wind farm three-phase voltage source converter （VSC）. The method can predict the reference current value of the next sampling instant within the current sampling time rapidly and accurately. Combined with the quality equation, the best reference voltage vector can be chosen for the next switch period. The corresponding switching signals can be obtained by the voltage space vector modulation （SVM）. Simulation results have shown the feasibility and effectiveness of the proposed method. It can eliminate the static error and discretization error, and achieve unity power factor operation.