【摘要】 二极管箝位型多电平变换器由于电容电压的平衡问题而在五电平以上很难在工业中推广应用,混和箝位技术为解决此问题提供了新的思路。该文在分析现有的基于混和箝位技术变换器的背景下提出了基于混和箝位技术的四桥臂多电平变换器。文中对四桥臂逆变器的电容电压平衡机理和PWM控制方法做了详细的阐述,从分析中可以看出混和箝位四桥臂多电平变换器不仅使得电容电压的平衡变得更加简单,箝位开关的工作频率可以高于主开关而使得系统的损耗减小,而且系统成本由于少用很多有源开关和电容而大大降低,是一种成本和性能兼得的好拓扑。最后,通过仿真和实验证明了该拓扑的有效性。更多还原

【Abstract】 Diode-clamped multilevel converters higher than five levels are seldom applied in industry due to the difficulty in balancing the capacitors’ voltages. The hybrid-clamped technique is a new idea to solve this problem. In this paper, a four-bridge hybrid-clamped converter topology is proposed based on the analysis of existing multilevel hybrid-clamped techniques. The detailed description is given on the balancing principle of capacitors’ voltages and control method of the four-bridge converter. The analysis shows that not only the cost of system is reduced quite a lot due to less active switches and capacitors used in this topology, the frequency of claming switches can be higher than main switches which leads to less power loss, but also the realization of the balance of capacitors’ voltages is easier and more effective compared with that of existing topologies. The four-bridge hybrid-clamped topology is a good topology when both cost and performance are considered. Simulations and experimentations have been carried out and the capacitors’ voltages can be balanced well.更多还原