一种并联输入并联输出的宽范围双向隔离DC/DC变换器

目前,DC/DC变换器广泛应用于新能源发电、电动汽车以及锂电池化成分容等领域。针对低压大电流双向功率传输应用场合,提出了一种输入并联输出并联的宽范围双向隔离DC/DC变换器。该变换器由2个相同的两级式DC/DC变换器组成,前级采用高效率LLC谐振变换器作为直流变压器,以实现电气隔离;后级采用交错式Buck/Boost变换器,保证宽范围电压输出和高动态性能。所提变换器能够实现功率的双向传输,且采用了一种功率方向改变时,无需进行功率流向判断与开关逻辑切换的调制策略,简化了系统的控制策略并提高可靠性。设计了1台3 kW的实验装置,实验结果验证了所提变换器及其控制方法的可行性和有效性。

Input-parallel-output-parallel Wide-range Bidirectional Isolated DC/DC Converter

At present, DC/DC converters are widely used in the fields of new energy power generation, electric vehicles, and lithium batteries. A bidirectional isolated Input-parallel-output-parallel DC/DC converter was studied for the bi-directional power transmission application field with low output voltage and high output current. The converter is composed of two identical two-stage DC/DC converters. The front stage uses a high-efficiency LLC resonant converter as a DC transformer to achieve electrical isolation. The interleaved Buck/Boost converter is used as the rear stage, which guarantees a wide range of output voltage and high dynamic performance. The proposed converter can realize bidirectional power transmission, and a modulation strategy without judgment of power flow direction and changing switch logic is adopted when the power flow direction changes, which simplifies the control strategy and improves reliability of the DC/DC converter. A 3kW experimental device was designed. Experimental results verify the feasibility and effectiveness of the proposed control method.