Research On Methods Of Improving Output Power Of Mine Intrinsic Safety Power Supply

In the coal,petrochemical and other fields,more and more electrical equipment is designed as intrinsically safe because of the more flammable and explosive gases in the production environment.The essential security of power supply is the basis of the essential security of the whole system.On the premise of discussing how to improve the output power of intrinsically safe switching power supply,this paper will design and develop A 18V/1.5A intrinsically safe switching power supply based on the single-ended flyback converter with simple structure and multi-channel output.The power supply has the advantages of small volume,good input-output isolation,multi-channel output and so on.It is suitable for multi-voltage level power supply in dangerous environment.Intrinsically safe switching power supply and general safety switching power supply is different from its internal can not contain large inductance,capacitance and other non-linear elements,otherwise when the circuit failure occurs,the instantaneous release of concentrated energy may ignite explosive gas mixture.The input rectifier filter circuit is an important part of the intrinsically safe switching power supply.In order to limit the large short-circuit current caused by capacitor short circuit,a resistor with a small resistance value was connected in series behind the capacitor,and a post-simulation circuit model with small resistance in series was built in Matlab to verify the effect of small resistance in series on limiting spark discharge energy.Secondly,the traditional input rectifier filter circuit is improved,that is,a two-stage input rectifier filter circuit is used to limit capacitor energy storage,so as to limit the spark discharge energy and improve the output power.Spark discharge mechanism research is the key of intrinsically safe power supply design and development,this topic through the study of spark discharge mechanism,the limit of intrinsically safe switching power supply output power factors,based on which to improve intrinsically safe switching power supply output power method.The essence of single-ended flyback converter is the energy storage inductance.Reducing the energy storage by increasing the working frequency of the power supply is also a safety measure to improve the quality of the power supply.This paper gives the main circuit and protection circuit design scheme,and the selection of important components are explained,calculation of the main parameters of flyback converter,PCB design according to the circuit,the production of experimental prototype and experiment.The test results of several important waveforms show that the output of the prototype is stable and has a certain load capacity,which can meet the design requirements.