【摘要】 基本的非隔离型升降压电路存在由二极管反向恢复带来的短路环问题.设计了一种基于Z网络的升降压DC/DC变换器,从电路结构上避免了短路环的存在,分析了Z网络和变换器的初始态阶跃响应,并设计了预充电电路,消除了变换器启动时的电压和电流尖峰,讨论了工作在电感电流连续模式(CCM,Current Continuous Mode)下的3种开关模态并分析了其工作原理,依照效率最优原则对升压和降压模式的开关模态进行简化,从而优化了变换器的控制方法,提出了一种通过合理选择电感电流纹波系数确保变换器工作在CCM模式下的方法,给出了各元器件的设计规则,并通过仿真和实验加以验证,结果与理论分析相吻合.更多还原

【Abstract】 Basic non-isolated buck-boost circuit exists the problem of short-circuit ring caused by the diode’s reverse recovery.A buck-boost DC/DC converter based on Z-sourse was designed.The presence of short-circuit ring was avoided from the circuit structure.The step response of initial state of the Z-network and the converter were discussed.The pre-charge circuits was also designed.The voltage and current spikes when the converter started were also eliminated.The three operation modes and operation theory of the converter was analysed when it worked in the situation of inductor current continuous mode(CCM).The operation modes of the boost and buck mode were simplified according to the principles of optimal efficiency,thereby the control strategy was also optimized.A method was presented to ensure the converter worked in CCM through choosing the reasonable inductor ripple factor.The design rules of the components was also given.Smulation and experimental results coincide with the theoretical analysis.更多还原