【作者】 陈武；

【导师】 阮新波；

【作者基本信息】 南京航空航天大学 ， 电力电子与电力传动， 2006， 硕士

【摘要】 零电压开关复合式全桥三电平(Zero-Voltage-Switching PWM Hybrid Full- Bridge Three-Level, ZVS PWM H-FB TL)变换器可以工作在三电平模式和两电平模式,在很宽的输入电压范围内,输出整流电压都接近输出电压,从而可以减小输出滤波器,因此可以提高变换器的功率密度和改善动态性能。因此该变换器可以适用于为燃料电池、太阳能电池供电和通讯电源等宽电压变化范围的应用场合。本文对H-FB TL变换器的软开关技术进行了进一步的研究。本文在基本ZVS PWM H-FB TL变换器中引入两只箝位二极管,无论是在三电平模式还是在两电平模式,都可以消除输出整流二极管反向恢复造成的电压尖峰和振荡,降低了输出整流管的电压应力。同时,该变换器保留基本的H-FB TL变换器的优点和特点。本文详细分析了该变换器的工作原理,讨论了开关管实现ZVS的条件,给出了变换器的参数设计,并进行了实验验证。为了消除输出整流二极管反向恢复造成的的电压尖峰和振荡,同时使所有开关管在很宽的负载范围内实现ZVS,本文提出了倍流整流方式的ZVS PWM H-FB TL变换器。论文详细分析了该变换器的工作原理,讨论了开关管实现ZVS的条件、阻断电容以及滤波电感值的选取等,最后进行了实验验证。本文还提出了一种电容箝位型ZVS PWM H-FB TL变换器,它是在基本ZVS PWM H-FB TL变换器中去掉两只续流二极管得到的。针对该变换器,本文提出一种新的控制方式。该变换器保留了基本变换器的优点,同时简化了电路结构。论文对该变换器进行了仿真分析,仿真结果验证了该变换器的可行性。更多还原

【Abstract】 The zero-voltage-switching (ZVS) PWM hybrid full-bridge three-level (H-FB TL) converter can operate in both three-level mode and two-level mode, the output rectified voltage is close to the output voltage over the entire input voltage range, thus the output filter can be reduced significantly, leading to high power density and fast dynamic response. So the ZVS PWM H-FB TL converter is very attractive for the applications such as fuel cells, photovoltaic cells, and telecom power supplies, where the voltage varies in a wide range. The objective of this paper is to do further research on the soft-switching techniques for the ZVS PWM H-FB TL converter.In order to eliminate the voltage oscillation and voltage spike across the rectifier diodes resulted by the reverse recovery, this paper introduces two clamping diodes into the basic ZVS PWM H-FB TL converter. The converter not only keeps all the characteristics of the basic ZVS PWM H-FB TL converter, but also eliminates the voltage oscillation and voltage spike across the rectifier diodes in both three-level mode and two-level mode, leading to a reduced voltage stress of the rectifier diodes.The operation principle and characteristics of the proposed converter are analyzed in detail, and the effectiveness is verified by a 1.2kW prototype converter.A current-doubler-rectifier (CDR) ZVS PWM H-FB TL converter is proposed in this paper, the proposed converter can achieve ZVS for all the switches in a wide load range with the use of the energy stored in the output filter inductance, in the meanwhile, the voltage oscillation and voltage spike across the rectifier diodes resulted by the reverse recovery are eliminated. This paper analyzes the operation principle, discusses the design of the block capacitor and the output inductance. A prototype converter rated 1.2kW is built in the lab to verify the effectiveness of the CDR ZVS PWM H-FB TL converter.By removing the two freewheeling diodes of the basic ZVS PWM H-FB TL converter, a capacitor-clamped ZVS PWM H-FB TL converter is obtained in this paper, and a new control strategy is proposed for the novel converter. The novel更多还原