宽ZVS负载范围4开关三电平直流变换器

提出一种4开关PWM三电平ZVS直流变换器,该变换器由传统三电平直流变换器和对称控制的半桥直流变换器复合而成。该电路非常适合高压直流变换领域。该变换器具有如下优点:所有开关串行联接,每个开关器件承受Vin/2的电压应力;4开关构造输出三电平,可有效减小输入输出滤波器并提高变换器的动态响应时间;所有开关器件在较宽的负载范围内实现软开关。文中分析了该电路的工作原理、软开关特性以及输入输出特性,并搭建了一套实验装置验证电路的基本工作原理。实验结果表明该电路工作原理正确,可以正常工作。

Four Switches Three-level DC-DC Converter with Wide ZVS Load Range

A novel 4 switches PWM ZVS TL DC-DC converter was proposed, which is composed of a conventional PWM TL half bridge converter and an uncontrolled HB converter. It is suitable for the high input voltage DC-DC power conversion. The presented topology has the following attractive features: all switches in the circuit sustain half of the input voltage without any static and dynamic voltage balance problem; only four active switches are used to synthesized TL output waveforms before output LC filter, which can significantly reduce the requirement for the input and output filter and improving system dynamic response; with proper designing, all switches can be operated under zero-voltage switching even with very small load current. The operation principle and characteristics of the proposed converter were discussed, and experiments were carried out to validate the proposed converter.