不对称电网电压下采用串联网侧变换器的DFIG运行与控制

Operation and Control of a DFIG-based Wind Turbine with Series Grid-side Converter under Unsymmetrical Grid Voltage Condition

针对电网电压不对称运行条件,提出一种适用于采用串联网侧变换器的双馈感应风电系统运行控制方案。所提控制方案通过分别抑制定子电压负序分量和抑制直流链电压二倍频脉动分量(同时可抑制系统总输出有功脉动),增强了不对称电压条件下双馈感应风电系统的运行性能。方案对所提出的系统控制策略进行了实验研究,结果验证了所提控制方案的正确性和有效性。

The control scheme for the doubly fed induction generator （DFIG） based wind- power generation system with series grid-side converter （SGSC） under unsymmetrical grid voltage condition is investigated in this paper. The simplified control models for the SGSC and parallel grid-side converter （PGSC） are established under dual synchronous dq axes respectively, and the simplified grid-side current reference values are achieved with orientation of grid positive-sequence voltage. The operational performance of the DFIG system under unsymmetrical grid voltage condition can be improved with the proposed scheme which restraining the stator＇s negative-sequence voltage component and the double supply frequency oscillations in DC-link voltage （also the pulsations of the total active power output）. The experimental results of a DFIG test rig with SGSC under unsymmetrical voltage conditions are used to verify the proposed control scheme.