The Study Of Endogenous Safety Power Supply Based On Flyback Converter

With the development of mechanization and intelligence in coal mine industry,all kinds of electrical equipment such as monitoring,detection,control and communication have been applied in underground coal mine.As the power supply core of these underground electrical equipment,the safety,reliability and stability are very important.However,the current intrinsic-safe power supply is not enough to meet the use of a large number of intelligent electrical equipment on the premise of ensuring safety.Therefore,it is of great significance to design a intrinsic-safe power supply with good protection effect and large output power for coal mine safety.n this paper,the intrinsically safe power supply is studied based on flyback converter,and a 12V/2.5A intrinsically safe power supply is designed.The transient spark energy generated by components such as capacitors and inductors in the event of circuit failure may detonate the combustible gas mixture,and the spark energy can be limited by designing suitable electrical parameters.Therefore,according to the requirements of essential safety,the spark discharge characteristics of CL circuit are studied.Through analysis and calculation,two mathematical models in the oscillating state and the non-oscillating state are established.Through Matlab software,the spark current,spark power and spark energy are simulated and analyzed,and the influencing factors of spark discharge are discussed.It provides a method to improve the intrinsic safety performance of the intrinsically safe power supply.The overall design scheme of the intrinsic safe power supply is determined,the relevant circuit parameters of the intrinsic safe power supply are formulated,and the circuit composition of the intrinsic safe power supply is designed,including the main circuit with the control chip UCC3802 as the core and the dual cut-off protection circuit with the control chip LT4363-2 as the core.According to the analysis of spark discharge in the third chapter,the capacitor,inductor and some important components are calculated and selected.Finally,the design is completed according to the intrinsic safety requirements,which lays the foundation for the subsequent simulation test.PISM simulation software and LTspice simulation software are used to simulate the designed safety power supply,and verify the prototype circuit design is reasonable.PCB design was carried out according to the designed circuit,the prototype was made,the prototype experiment platform was built,the working waveform of the prototype was tested,and the prototype’s intrinsic safety performance was evaluated.The experimental results show that the output of the prototype is stable,the protection effect is good,basically meet the design requirements.Fig.[65] Table [7] Ref [82]...