改进单周期控制策略的双向大变比DC-DC开关变换器

Bi-directional DC-DC Converters With Large Conversion Ratio Based on Improved One-cycle Control

大变压比的双向DC-DC变换器广泛地应用于电池的充放电系统、电动汽车、不间断电源、启动/发电系统、光伏发电系统和航空电源系统等场合,其重要性能指标是效率、质量和成本。但是传统非隔离型双向DC-DC变换器在高频下难以取得较大变压比,同时会导致较大的电压电流应力和较大的损耗。为实现非隔离型双向DC-DC变换器的大变比应用,将耦合电感引入非隔离双向DC-DC变换器,实现输入输出电压大变比和效率提升;针对新型双向大变比直流变换器升降压Buck/Boost电路,提出一种改进单周期控制模型,该模型基于所提电路不同工作模式下的有效占空比并结合输出反馈补偿控制,实现有效控制和提高负载的动态响应能力。分析具有耦合电感双向DC-DC开关变换器的工作原理和控制特性,并通过计算机仿真和样机实验验证了所提电路和控制策略具有更高的转换效率、更强的鲁棒性和优良的抗扰动能力。

The large conversion ratio bi-directional DC-DC converter is widely applied in charge and discharge battery systems, automatic cars, uninterruptible power supplies （UPS）, generator systems, photovoltaic systems and aero power supplies, etc. The efficiency, size and cost are the key properties for these applications. A novel coupled-inductor bi-directional DC-DC converter is proposed and analyzed in this paper, which can overcome the shortage of non-isolated bi-directional DC-DC converters that its conversion ratio is restricted in a small range. This paper analyzes the principle and control model of the proposed converter. To accomplish the prominent dynamic performance of the large conversion ratio bi-directional DC-DC converters, the different operating modes are investigated and a improved control model is deduced from one-cycle control （OCC） technique based on effective duty ratio combined with optimum feedback compensation strategy. The novel converter combined with improved OCC control strategy is built. The computer simulation and experimental results verify the higher efficiency, good robust and fast response performance of the proposed circuit and its improved control strategy.