Calculation and Analysis of Residual Energy Storage in Intrinsically Safe Buck Converter

Intrinsically safe circuits used in explosive gas environments require optimized design of circuit parameters to meet the performance requirements of intrinsically safe circuits. Because there are nonlinear components such as transistor and energy storage components such as inductors and capacitors in the Buck circuit, the Buck circuit is a complex circuit. The minimum ignition voltage (MIV) curve and minimum ignition current (MIC) in GB3836.4-2010 cannot be directly used. The curve assists in the design of the intrinsically safe circuit parameters, and the overall energy constraints must be applied to make the circuit meet the intrinsically safe circuit performance requirements. By analyzing the residual energy in the energy storage component after the transistor is disconnected from the Buck circuit operating in CCM mode, the calculation formula of the residual energy is obtained, and the relationship between the residual energy and the circuit parameters is analyzed, , and the residual energy is minimized. When the remaining energy reaches the minimum value, the corresponding inductance value L=R(1-D)/2f corresponds to the critical condition of the two working modes of the Buck circuit (CCM/DCM). The relationship between frequency (f) and duty (D); the calculation of residual energy is mainly to improve the safety factor of the intrinsically safe circuit, and the change of the calculation formula of residual energy will cause the safety factor of the intrinsically safe circuit to change. The parameters need further correction calculation. The analysis results of this paper provide guidance for the intrinsically safe Buck circuit to optimize the circuit parameters and improve the intrinsic safety performance of the circuit.