传统的零电压零电流开关(ZVZCS)PWM DC/DC变换器存在滞后桥臂ZVS范围小、控制复杂、环流损耗大等问题.针对这些问题,介绍了一种新型的DC/DC PWM变换器,通过在滞后桥臂上并联一个辅助网络,来实现在较宽的负载范围内滞后桥臂零电压开通,重载下零电流开通.利用UC3879来实现瞬时值移相控制方式,给出了外围连接电路,并对相关参数进行了计算.用该方法设计了一台300WDC/DC电源模块,实验表明,可以在较宽的负载范围内实现滞后桥臂的零电压开通,重载下实现零电流开通,重载效率可以达到93%以上.%Aiming at the conventional ZVZCS PWM DC/DC converter has disadvantages such as the narrow lagging leg zero-voltage-switch rang, complexity of control and big circulating current losses, the paper proposed a novel zero-voltage and zero-current switching ( ZVZCS ) phase-shifted full-bridge DC/DC converter using the auxiliary network. The converter could achieve the zero-voltage lagging leg switch in the wide load range and the zero-current switching in the heavy load. The paper gaves the peripheral circuit and calculation of interrelated parameters and a DC/DC converter of 300W. The experiment was given to verify the validity of the proposed theory and the efficiency of the heavy can achieve 93％.
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