限流熔断器电弧能量的简化计算与分析

Simplified Calculation and Analysis of Current Limiting Fuse Arc Energy

提出电弧电压在电弧燃炽过程中恒定这一简化假设,推导了直流和交流情况下电弧能量计算公式.基于该公式分析了电弧能量和电弧电压的关系,发现电弧能量随电弧电压增高而降低,当电弧电压均值约为额定电压的2.5～3.0倍时,可以使电弧能量降低到合适水平.进一步分析了电弧能量和预期短路电流、短路时间常数（直流）或短路相角（交流）的关系.分析表明：直流情况下电弧能量受时间常数影响最大,随时间常数单调增加;交流情况下电弧能量与短路电流和短路相角都有显著关系,最大电弧能量大约出现在中等短路电流和0°短路相角处.这为限流熔断器的过电压设计和最大电弧能量短路分断试验参数的选择提供参考.

Arc voltage was assumed to be invariable during the arcing period, then, expressions of arc energy in DC and AC conditions were given respectively. Analysis of the relationship between arc energy and arc voltage shows that arc energy decreases with the arc voltage increasing, arc energy will decrease to an appropriate level when arc voltage takes 2.5 ~ 3.0 times of rated voltage. After that, the relationships between arc energy with prospective fault current amplitude and time constant （DC condition） or making angle （AC condition） were analyzed. The analysis shows that,in DC condition, arc energy mostly depends on and increases with time constant. In AC condition, arc energy depends on both fault current and making angle, the maximum arc energy occurs on medium prospective fault current,nearby 0° making angle. The conclusion can be applied to the design of CLF over voltage and the parameters selection of maximum arc energy breaking test. Key words：