双馈风力发电系统并网逆变器不同控制策略分析

双馈风力发电系统并网逆变器采用并网电流反馈PI控制,虽然在理想电网条件下能够实现逆变器控制系统高功率因数、低稳态误差的性能,但存在电网谐波干扰情况时,系统的动稳态跟踪性能变差;此外,PI控制器可以直流信号实现零稳态误差,但无法消除交流信号的谐波分量,且需要多次的复杂坐标变换和解耦控制。由此,提出一种基于并网电流反馈、电容电流反馈的多谐振PR控制,提高了系统控制精度;引入低次谐波补偿项后,能够有效抑制并网电流波形畸变。仿真结果证明了提出的控制策略不仅能实现对交流信号无静差控制和具有良好的动稳态跟踪性能,而且系统并网电流的谐波含量较少,满足电网对风力发电系统并网的要求。

Comparative Analysis of Inverter Different Control for Double-fed Wind Power Generation System

The double-fed wind power generation system and network grid inverter with current feedback PI control, although under ideal conditions can be achieved grid inverter control system, high power factor, low steady-state error performance, but there are harmonic interference when the situation, steady state and dynamic tracking performance deteriorates; in addition, PI controller can achieve zero steady-state error to DC signal, but do not eliminate the harmonic components of the AC signal, and the need for complex coordinate transformation and decoupling control several times. Thus, this paper proposes a grid-current feedback of multi-resonant PR capacitor current feedback control,and improve the control precision; the introduction of low-order harmonics compensation item, can effectively inhibit the grid current waveform distortion. Simulation results show that the proposed control strategy can not only realize the AC signal no static error control and has good dynamic and steady-state tracking performance, but also the system and less net current harmonic content, to meet the power and wind power system network claim.