Z源网络强化励磁提高低速SRG效率

Research of high efficiency based on Z-source network strength excitation for SRG in low speed period

针对低风速段开关磁阻风力发电机的运动电动势低于发电电动势、导致发电区间小于励磁区间的问题,将Z源网络耦合到励磁电源与不对称半桥功率变换器之间,强化励磁电压,加快励磁电流上升速度,减小励磁区间,提高低速发电效率;同时给励磁电容充电,实现快速自励;并通过Z源网络实现滤波,节省成本,减小体积。Matlab仿真实验表明:与传统不对称半桥功率变换器相比,基于Z源网络新型功率变换器能明显提高SRG在低速段风能利用率和发电效率。20 k W小功率样机测试结果也验证了新型Z源网络功率变换器能优化开SRG低速性能。

In low wind speed,the motional electromotive force of switched reluctance generation（ SRG） is lower than the generation electromotive force,resulting in generate electricity interval less than the excitation interval. Aiming at these problems,Z-source network was coupled between the excitation power source and asymmetrical half-bridge power converter. It has many advantages,such as strengthen the excitation voltage,accelerating the rising speed of excitation current,shrinking excitation interval,increasing the efficiency of low speed power generation,and charging the excitation capacitor to achieve rapid self excitation. The cost can be saved,and volume can be reduced with self-filter by Z-source network.MATLAB simulation result shows that the new power converter based on Z-source network can improve the low speed wind energy utilization and SRG power generation efficiency,compared with the traditional asymmetrical half-bridge power converter. Small power prototype test result also verified that the new Zsource network power converter can optimize SRG low performance.