buck变换器的输出本质安全特性分析及优化设计

用buck变换器的电感和电容的最大储能之和反映其输出短路释放能量，推导了buck变换器在连续导电模式（CCM）和不连续导电模式（DCM）下的最大输出短路释放能量，若它们部小于最小点燃放电能量，则该变换器是满足输出本安要求的。指出如果变换器在最小负载电阻和最高输入电压的情况下处于CCM，则该状态下的输出短路能量就是该变换器在整个工作范围的最大输出短路释放能量。根据输出纹波电压指标将最小输出电容值用电感表示出来，并通过令最大输出短路释放能量对电感的偏导数为0的方法，得出在给定设计指标条件下使最大输出短路释放能量最小的电感和电容设计参数。实验结果验证了理论分析的正确性。

OUTPUT INTRINSICALLY SAFE BEHAVIOR OF BUCK CONVERTERS AND ITS OPTIMAL DESIGN

The summation of the stored energy of the inductor and the capacitor of a buck DC-DC converter is regarded as the output short-circuit discharged energy. The output short-circuit discharged energy of the converter in CCM and DCM are deduced, respectively. If they are both less than the minimum ignition discharged energy, the converter meets the requirement of output intrinsic safety. It is pointed out that the output short circuit dischanged energy reaches its maximum value for X CCM buch converter in case of the highest input voltage and th minimum load resistance. The capacitance is expressed by the inductance according to the desired output voltage ripple level. Taking the derivatives with respect to inductance on the output short circuit discharged energy and letting the results to be zero, the optimal values of inductance and capacitance are obtained. The experiment results are in positive to the analysis results showing the feasibility of the proposed methods.