混合型本安电路短路瞬态能量分析

Short circuit transient power analysis of hybrid intrinsically safe circuit

目前针对本安电路本安特性的研究大多以IEC火花实验装置为实验平台,仅对单一电容电路或电感电路的放电特性进行分析,存在适用性差、实验条件要求高等问题,缺少对混合型本安电路本安特性的研究。针对该问题,在GB/T 3836.4—2010《爆炸性环境第4部分:由本质安全型“i”保护的设备》的基础上,以截流型保护方式下的混合型电路为实验对象进行短路瞬态能量实验,通过分析短路瞬态能量释放过程,建立了短路瞬态能量数学模型,分析了等效数学模型中电容、电感、电源电压和保护时间对短路瞬态能量的影响。Matlab仿真结果表明:随着电容和电感的增大,短路瞬态能量会逐渐增大,最后趋于一个稳定值;增大电源电压会显著增加短路瞬态能量;缩短动作保护时间可有效降低瞬态能量,但只有当保护时间小于临界时间时其作用才明显。基于短路瞬态能量数学模型开发了本安电源,进行了短路实验。实验结果表明:短路电流和电压波形与理论分析基本吻合,短路瞬态能量为33.22µJ,符合本安要求,可为本安电源的设计提供参考。

Currently,research on the intrinsically safe features of intrinsically safe circuits mostly relies on the IEC spark experimental device as the experimental platform.The research only analyzes the discharge features of a single capacitor or inductance circuit.There are problems such as poor applicability and high requirements for experimental conditions.There is a lack of research on the intrinsically safe features of hybrid intrinsically safe circuits.To solve this problem,based on GB/T 3836.4-2010 Explosive Atmospheres-Part 4:Equipment Protected by Intrinsic safety Type"i",a short circuit transient energy experiment is carried out with the hybrid circuit under the cutoff type protection mode as the experimental object.By analyzing the release process of short circuit transient energy,a mathematical model of short circuit transient energy is established.The paper analyzes the effects of capacitance,inductance,power supply voltage,and protection time on short circuit transient energy in the equivalent mathematical model.The Matlab simulation results show that as the capacitance and inductance increase,the transient energy of the short circuit will gradually increase and eventually approach a stable value.Increasing the power supply voltage will significantly increase the short circuit transient energy.Shortening the time is less than the critical time.An intrinsically safe power supply is developed based on a mathematical model of short circuit transient energy.The short circuit experiments are conducted.The experimental results show that the waveform of short circuit current and voltage is basically consistent with theoretical analysis.The transient energy of short circuit is 33.22µJ,which meets intrinsic safety requirements and can provide a reference for the design of intrinsically safe power supplies.