【摘要】 移相全桥DC/DC变换器普遍应用于大功率场合,由于其开关管能实现零电压开通,大大提高了变换效率。然而滞后臂比超前臂开关较难实现零电压开通,通常情况下,轻载时,滞后臂运行在硬开关状态。硬开关状态下,由于米勒电容的存在,开关管的动作会使其他开关管的门极电压发生振荡而再开通。深入研究了米勒效应的原理,以及移相全桥DC/DC变换器在超前臂零电压开通,滞后臂硬开关的情况下,米勒效应对其影响。提出了抑制米勒效应的方法,并通过4.8 kW实验样机证实了方法的可行性。更多还原

【Abstract】 The IGBT phase shifted full bridge DC/DC converter is widely used in high-power situations, because it can realize zero voltage switching, greatly improving the transformation efficiency.However, the hysteresis arm is more difficult to achieve zero voltage switching than leading arm.Usually, the hysteresis arm runs in the hard switching state at the light load. Under the condition of hard switching, the action of the switch will cause the gate voltage of the other switch to oscillate and closes incorrectly, because of the existence of Miller capacitance. In this paper, the principle of Miller effect is studied deeply, and the effect of the Miller capacitance based on the phase shifted full-bridge DC/DC converter in the case of leading arm with zero voltage switching and hysteresis arm without zero voltage switching is researched. A method to suppress Miller effect is proposed, and the feasibility of the method is proved by 4.8 kW Experimental prototype.更多还原