Analysis the Output Voltage Ripple of Intrinsically Safe Buck Converter with Output Low Pass Filter

To further improve the output power of the intrinsically safe Buck converter, and ensure to meet the requirement of the output ripple voltage (ORV) in the case of the rather small inductance and capacitance, the Buck converter with output low pass filter (LC-Buck converter) is proposed. The ORV of LC-Buck converter is analyzed within the given input voltage and load resistance ranges. It is indicated that the ORV reaches to the maximum value (MORV) when both Vi and RL are the maximum, moreover, the design methods of the inductance and the capacitance are proposed. For the same electrical performance index, the designed value of inductor and capacitor of the LC-Buck converter are compared with that of the typical Buck converter. It is concluded that the inductance and the capacitance of the LC-Buck converter are much smaller than that of the typical Buck converter. It is showed that smaller inductance and capacitance are needed to meet the requirement of the electrical performance index in proposed LC-Buck converter, which is helpful to improve the intrinsically safe performance and the intrinsically safe output power. The validity of theoretical analysis of the proposed design methods is verified by the simulation and experimental results.