新型并联谐振直流环节软开关逆变器改进调制策略  

Improved Modulation Strategy of Novel Parallel Resonant DC Link Soft-Switching Inverter

作　　者：李思 杨明[1] 马宇 宋天佑 徐殿国[1] Li Si;Yang Ming;Ma Yu;Song Tianyou;Xu Dianguo(School of Electrical Engineering and Automation,Harbin Institute of Technology,Harbin 150001 China;Beijing Machine and Equipment Institute, Beijing 100854 China)

机构地区：[1]哈尔滨工业大学电气工程及自动化学院,哈尔滨150001 [2]北京机械设备研究所,北京100854

出　　处：《电工技术学报》2024年第2期487-500,共14页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52277038)。

摘　　要：针对新型并联谐振直流环节软开关逆变器的辅助电路运行过程中电流应力高、导通损耗大的问题,提出一种基于不连续的脉冲宽度调制且采用斜率正负交替锯齿载波的改进调制策略。与原调制策略相比,首先,该文所提调制策略在保留辅助电路动作频率最小化优点的基础上,不仅实现了全部开关管的软开关,而且将第二辅助开关管的电流应力降为谐振电流峰值。然后,通过合理的参数设计,进一步降低辅助电路电流应力,从而减少辅助电路损耗。然后,根据所提调制策略分析工作原理、对比不同文献、规划参数设计、进行损耗分析。最后,使用SiC MOSFET制作一台5 kW/40 kHz通用样机,通过实验验证所提调制策略对原拓扑效率提升与电流应力降低的有效性。With the continuous development of wide band gap devices represented by SiC MOSFET,the problems of high switching loss and strong electromagnetic interference of wide band gap inverters under high frequency have become increasingly prominent.To solve these problems,researchers put forward soft-switching inverter technology.In medium and small power applications,the resonant DC link soft-switching inverter(RDCLSI)is the first choice.After years of development,RDCLSI gradually transited to parallel RDCLSI(PRDCLSI),but the existent PRDCLIs have the following problems.Using two electrolytic capacitors as auxiliary power supply leads to the change of neutral point potential.The coupled inductor is used to replace the split capacitor,but the existence of coupled inductor makes the parameter design very complicated.Setting the inductor current threshold increases control complexity.The topology proposed in the reference“Parallel resonance DC link inverter topology and analysis of its operation principle”(Ref.[15])and the reference“RDCL three-phase inverter and load adaptive commutation control”(Ref.[16])can solve the above problems well.However,it is not perfect,and its auxiliary circuit has the problem that the current stress and operation times cannot be optimized at the same time.Therefore,this paper proposes an improved modulation strategy based on discontinuous pulse width modulation(DPWM)and adopting sawtooth carriers with alternating slopes.Firstly,the composition of the improved modulation strategy is introduced.The clamped basis of DPWM is that the phase with the largest absolute value of load current is clamped.If the load current of this phase is positive,the main switch of the upper bridge leg of this phase will keep conducting.Otherwise,the main switch of the lower bridge leg will keep conducting.The changing basis of the sawtooth carrier slope is that if the load current is also positive,the sawtooth carrier slope is positive.Otherwise,the sawtooth carrier slope is negative.Secondly,according to th

关 键 词：并联谐振直流环节 辅助电路 调制策略 电流应力 导通损耗 

分 类 号：TM464[电气工程—电器]