一种非对称级联H桥三相逆变器的功率均衡混合随机脉宽调制方法  

A Power-Balanced Hybrid Random Pulse Width Modulation Method for Asymmetric Cascaded H-Bridge Three-Phase Inverter

作　　者：刘剑锋 龚仁喜[1] 张圆圆[1] Liu Jianfeng;Gong Renxi;Zhang Yuanyuan(School of Electrical Engineering Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学电气工程学院,南宁530004

出　　处：《电工技术学报》2024年第24期7807-7820,共14页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(61561007);广西自然科学基金(2017GXNSFAA198168)资助项目。

摘　　要：为了降低电压比为1∶1∶1∶3的非对称级联H桥三相逆变器输出线电压的脉宽调制(PWM)噪声峰值,该文提出一种融合阶梯波调制、同相载波层叠调制、随机调制及功率均衡的功率均衡混合随机脉宽调制(PB-HRPWM)方法。该方法可概述为:(1)通过高压H桥单元的调制波与参考电位相比较,产生高压H桥单元的驱动脉冲和低压H桥单元的调制波;(2)通过同相层叠随机载波与低压H桥单元的调制波相比较,产生随机脉冲;(3)通过脉冲逻辑运算方法对随机脉冲按照0.5T_(ah)进行循环分配,得到低压H桥单元的驱动脉冲;(4)使用高低压H桥单元的驱动脉冲控制三相逆变器的运行。仿真和实验结果表明:该方法可以降低线电压PWM噪声峰值,同时实现低压H桥单元之间的功率均衡。相比传统的随机和非随机PWM方法,所提PB-HRPWM方法具有更低的线电压PWM噪声峰值和更小的线电压总谐波畸变率(THD)。最后,通过仿真对比和实验验证了所提PB-HRPWM方法的有效性和可行性。With the continuous development of power electronics technology,three-phase voltage source inverters controlled by pulse width modulation(PWM)have been widely used in AC drive systems,electric vehicles,and ships.Such methods have fixed carrier frequency,and the PWM noise peak of line voltage is very high,causing acoustic noises in the motor and electromagnetic noises in the inverter.Scholars have proposed various random PWM methods to suppress PWM noise peaks,such as RPWM method optimization from random algorithms and carrier sequences.The in-phase disposition pulse width modulation(IPD-PWM)has a smaller THD of line voltage than the phase-shifted pulse width modulation(PS-PWM).However,these modulation methods are mainly applied to single H-bridge inverters.Compared with single H-bridge inverters,cascaded H-bridge inverters have a smaller total harmonic distortion(THD)of output voltage.In addition,asymmetric cascaded H-bridge inverters have a larger output power and a smaller output voltage THD than symmetric cascaded H-bridge inverters.Therefore,this paper proposes a power-balanced hybrid RPWM(PB-HRPWM)method for asymmetric cascaded H-bridge three-phase inverters with a voltage ratio of 1∶1∶1∶3.The proposed PB-HRPWM method can be summarized as follows.(1)The driving pulses of the high-voltage H-bridge unit and the modulation wave of the low-voltage H-bridge unit are generated by comparing the modulation wave of the high-voltage H-bridge unit with the reference level.(2)The random pulses are generated by comparing in-phase random level-shifted carriers with the modulation wave of the low-voltage H-bridge unit.(3)The random pulses are circularly distributed according to 1/2 Tah by pulse logic operation method to obtain the driving pulses of the low-voltage H-bridge unit.(4)The driving pulses of high and low-voltage H-bridges control the operation of the three-phase inverter.The proposed PB-HRPWM method effectively reduces the PWM noise peak of line voltage,and the power balance between the low-voltage H-bridg

关 键 词：多电平逆变器 级联H桥 脉宽调制 噪声 功率均衡 

分 类 号：TM464[电气工程—电器]