一种双不对称升压倍增单元的耦合电感Boost变换器

Two asymmetric voltage multiplier cells Boost converter with coupled inductor

为了满足光伏发电并网系统对DC/DC变换器的要求和解决耦合电感变换器的电压尖峰,提出一种无电压尖峰的高升压Boost。该变换器有如下特点:采用两组不对称倍压单元,提高了变换器的升压能力,同时又消除了耦合电感二次侧绕组因续流引起的高突变电压;采用不对称倍压单元中的电容与二极管构成无源无损钳位电路,避免额外增加钳位电路,降低了成本;漏感的能量得到吸收,提高了变换器的效率;同时,降低了开关管和输出二极管的电压应力,降低了变换器对器件的要求。详细分析了变换器的工作原理,并给出了关键性的公式推到和设计依据。最后,搭建了一台200 W的试验样机,实验验证了理论的正确性,满足了电网的需求。

In order to meet the requirements of DC/DC converter in photovoltaic grid-connected systems and solve voltage spike of converters with coupled inductor,a novel Boost converter with coupled inductor is proposed,which voltage spike is eliminated.The proposed converter has the following characteristics.First,two sets of asymmetric voltage multiplier cells are adopted,so its voltage gain is increased and high voltage spike introduced by flow-continued current from secondary winding of coupled inductor is eliminated.Second,clamp circuit is composed of capacitors and diodes from the cells.So that extra clamp circuit is not necessary and the cost is decreased.Moreover,leakage energy is recycled and efficiency is enhanced.Finally,devices requirements are decreased because of reduced voltage stresses of switch and output diode.The operating principle is analyzed in detail,and critical formulas and design are presented.Finally,a prototype circuit at 200 W output power is established to verify the performance of the proposed converter and the requirements of power grid are satisfied.