基于Buck变换器的开关磁阻发电机新型励磁模式

THE NOVEL EXCITATION STRATEGY FOR SWITCHED RELUCTANCE GENERATORS BASED ON BUCK COVERTER

提出了基于Buck变换器的开关磁阻发电机(SRG)新型励磁模式。给出并分析新型模式的功率变换器主电路,每相桥臂只需1个主开关器件和1个续流二极管;直流侧电容两端加一个Buck变换器,SRG的输出电压经Buck变换器降压后作为励磁电压,将输出的部分能量回馈到励磁电容,实现励磁。该励磁模式无需外部励磁电源,改变占空比D或通过Buck变换器闭环控制可独立调节励磁电压,且D>0.5时有利于提高输出功率。建立SRG新型励磁发电系统仿真模型,仿真结果表明系统能稳定运行,励磁电压独立可控,发电质量较好,验证了所提出的新型励磁模式的可行性和优越性。

A novel excitation strategy of switched reluctance generators base on Buck converter was proposed. The main circuit of power converter was presented and analyzed. One main switch and a freewheeling diode were needed for each phase. Buck converter was added across the DC link capacitor. The output voltage was bucked to excita- tion voltage. The part of output energy of SRG was returned to the excitation capacitor, and SRG is excited. Under novel excitation strategy, external excitation power could not be needed, and excitation voltage could be adjusted independently by switch duty cycle or closed-loop control of Buck converter. Furthermore, the output power could be increased when D 〉 0.5. The simulation model of switched reluctance generating system based on novel excita- tion was established. The simulation results showed that the system can work stably, excitation voltage can be con- trolled independently and generating quality is good. It verifies the feasibility and superiority of the proposed method.