宽风速运行的定子双绕组感应电机风力发电系统励磁电容的优化方案

将控制侧静态励磁控制器(SEC)的直流母线端和功率侧整流桥的输出端通过功率二极管并接起来,可使定子双绕组感应电机(DWIG)风力发电系统在宽风速范围内输出恒定的高压直流。鉴于新拓扑和新系统控制策略的特殊性,本文详细分析了系统在高低风速两种运行状态下的控制绕组电流变化规律,并在此基础上以SEC容量最小为目标,研究了新系统的励磁电容优化方案。方案运用Simulink仿真得到励磁电容变化对控制绕组电流的影响,并依据仿真结果运用循环计算和实验验证相结合的方法,最终得到最优的励磁电容值及最佳的切换转速。实验结果证明了该优化方案的正确性和有效性,新系统在保持SEC容量为电机额定功率1/3的情况下实现了宽风速运行,充分利用了低风速下的风能。

Optimal Scheme of Excitation Capacitor for Dual Stator-Winding Induction Generator Wind Power System Over a Wide Wind Speed

The dual stator-winding induction generator(DWIG) wind power system output high DC voltage over a wide wind speed by means of the parallel structure.The DC bus of the static excitation converter(SEC) on the control side is connected with the output terminal of the rectifier bridge on the power side through a unidirectional diode.In consideration of the new topology and the particular control strategy,the change law of the control-winding current under two operation situations is analyzed in detail in this paper.On that basis,the optimal scheme of excitation capacitor for the new system is investigated to minimize the capacity of SEC.According to simulation results of the influence on the control-winding current by excitation capacitor,the circulation calculation and experimental verification are employed to achieve the optimal excitation capacitor and switchover motor speed.Experimental results demonstrate the accuracy and effectiveness of the optimization scheme.Keeping the capacity of SEC still one third of the rated power,the new system achieved in operating over a wide speed range and exploiting wind energy under low wind speed.