Research On Coal Mine Intrinsically Safe Switching Power Supply

Due to the rapid development stage of society, the increasing demand of coal, coal is still widely used as an important energy. Meanwhile coal mine also conform to the development of technology, the new highly integrated intelligent electrical devices have been widely applied to coal mines and other explosive occasions. Demand for the construction of digital mine, mine detection monitoring equipment number is increasing, these electronic devices are needed to supply power from the underground, which is equivalent to the electrical power supply device,"heart", plays an important role in the power supply system. So, it’s intrinsically safe design is the basis of the nature of the security system. Compared to traditional linear intrinsically safe power supply, switching power supply intrinsically safe compact, low cost, high security, better able to achieve intrinsically safe output power can ensure the safety of electrical equipment in hazardous environments. Buck-Boost converter which based on intrinsically safe switching power is studied and analyzed, and designed a12V/1A output switching power supply intrinsically safe in this paper.In hazardous environments, it is required to meet the spark generated when the circuit failure does not ignite surrounding combustible gas mixture. To analyze the discharge circuit modeling during short circuit, capacitance inductance circuit electric spark is produced, it provides theoretical basis for the design of the safety power supply. On the concrete analysis of the characteristics of the Buck-Boost converter, mainly to the inductance and output filtering capacitance transducer to design. Detailed analysis of the characteristics of the Buck-Boost converter, mainly on the converter output filter inductor and capacitor design. The characteristics of the converter in-depth analysis, there are three operating modes:CISM-CCM mode, IISM-CCM mode, IISM-DCM mode in the Buck-Boost converter. A conclusion at the same time in the dynamic range of maximum output ripple voltage, maximum inductor current and short circuit when the release of energy. Maximum ripple voltage and maximum output short circuit release energy to reach appropriate judgments based on the safety.Design the intrinsically safe switching power supply of the main circuit and protection circuit, analysis of important components of the specific parameter calculation and selection, on this basis made of intrinsically safe switching power supply prototype. Finally, the test results show that the intrinsically safe switching power supply output is stable, ripple voltage less than the specified value, basic can meet the requirements of this intrinsically safe.