一种低输入电流总谐波畸变率的三相Buck整流器不对称调制策略  

An Asymmetric Modulation Strategy for Three-Phase Buck Rectifier with Low Input Current Total Harmonic Distortion

作　　者：曹海彬 许建平[1] 谢飞 周琛力 陈欣 Cao Haibin;Xu Jianping;Xie Fei;Zhou Chenli;Chen Xin(Key Laboratory of Magnetic Suspension Technology and Maglev VehicleMinistry of Education School of Electrical Engineering Southwest Jiaotong University,Chengdu 610031 China)

机构地区：[1]西南交通大学电气工程学院磁浮技术与磁浮列车教育部重点实验室,成都610031

出　　处：《电工技术学报》2024年第8期2541-2552,共12页Transactions of China Electrotechnical Society

基　　金：国家自然基金资助项目(61733015)。

摘　　要：传统空间矢量脉宽调制(SVPWM)三相Buck整流器没有考虑直流链电流纹波对输入电流的影响,且在扇区切换点处输入电流存在严重畸变,导致输入电流总谐波畸变率(THD)升高。该文分析直流链电流纹波对三相Buck整流器输入电流的影响,分析输入电流扇区切换点畸变产生的原因,提出一种新型不对称SVPWM策略,显著降低了三相Buck整流器的输入电流THD。最后,通过仿真和1 kW的实验样机验证了理论分析的正确性以及所提调制策略的有效性。The input current total harmonic distortion(THD)is an important performance indicator of a three-phase Buck rectifier,closely related to the modulation strategy.When calculating the dwell time of the vector in the previous research on space vector pulse-width modulation(SVPWM),the ripple of the DC-link current was ignored,i.e.,it was considered a constant value.However,in practical applications,to improve dynamic performance and power density,the output inductor of the three-phase Buck rectifier takes a small value,which leads to a large DC-link current ripple.In this case,the impact of the DC-link current ripple on the input current becomes obvious.Secondly,the input current of the three-phase Buck rectifier with the conventional SVPWM modulation strategies has severe distortion during the sector transition.Therefore,this paper proposes a low input current THD modulation strategy,which considers the influence of DC-link current ripple on the input current quality and eliminates the input current distortion during the sector transition.Therefore,the input current THD is effectively reduced.The impact of the DC-link current ripple on the input current is analyzed in this paper.Firstly,based on the operating states of the three-phase Buck rectifier in sector 1,the relationship between the input current of the three-phase bridge arm and the DC-link current is obtained.Secondly,the relationship between the input average equivalent current amplitude of the three-phase bridge legs is analyzed for different modulation strategies.Then,the amplitude relation between the input voltage and the corresponding input current is obtained.When the ripple of the DC-link current is large,the results show that the ratio of the three-phase input current to the corresponding input voltage is not equal to the conventional asymmetric modulation,which leads to a high harmonic content in the input current.For the conventional symmetric modulation,the ratio of the three-phase input current to the corresponding input voltage is equal,which

关 键 词：三相Buck整流器 直流链电流纹波 输入电流畸变 不对称调制策略 

分 类 号：TM461[电气工程—电器]