Method for designing intrinsic safety type quasi-resonance flyback converter

The invention discloses a method for designing an intrinsic safety type quasi-resonance flyback converter. The method comprises the steps that firstly, according to design requirements, parameters and performance indexes of the intrinsic safety type quasi-resonance flyback converter are set; then, the largest current ILSP, max and the minimum output capacitance Cmin of the intrinsic safety type quasi-resonance flyback converter are calculated; the maximum released energy W1max of spark discharge is calculated when Q is switched off, and the maximum released energy W2max of short-circuit spark discharge is calculated when Q is switched on; finally, the intrinsic safety performance of output of the designed quasi-resonance flyback converter is judged, if output of the quasi-resonance flyback converter satisfies the intrinsic safety, design is accomplished, and if output of the quasi-resonance flyback converter does not satisfy the intrinsic safety, redesign is conducted. The method for designing the intrinsic safety type quasi-resonance flyback converter meets the requirement of the DC-DC conversion portion inside an isolated type intrinsic safety power source, the functions that the dynamic performance of the converter is good and the converter can rapidly respond to the electrical performances such as load fluctuation are achieved, and the intrinsic safety performance of the converter is guaranteed.