针对硬开关PWM变换器的开关损耗大的问题，主电路采用ZVS PWM全桥变换器电路拓扑。通过变压器原边隔直电容与变压器漏感的谐振作用，实现功率管零电压开关。控制电路基于UC3879设计了双闭环控制系统。开关变换器将电流峰值作为控制对象，电流内环降阶处理等效为一个比例环节，电压外环采用带电容反馈的PI调节器。推导了整个系统的传递函数，并对调节器参数进行设置。通过Matlab仿真及实验测试，验证了设计结果的正确性。使系统达到良好的控制指标。%ZVS(zero-voltage-switching)PWM full-bridge converter circuit topology is adopted in the main circuit to elimi-nate the energy loss caused by the hard-switching PWM converter. The zero-voltage switching of power tube was realized ac-cording to the resonance effects of transformer leakage inductance and primary blocking capacitor. The double-loop control sys-tem of the control circuit was designed based on UC3879. Switching converter takes current peak as the controlling object. The reduced order processing of current inner-loop is equivalent as a proportional link. The PI regulator with capacitive feedback is adopted in the voltage outer-loop. The transfer function of the whole system was derived. The regulator parameters was set. The correctness of the result was validated through Matlab simulation and experimental testing. The fine control index of the system was achieved.
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