基于卡拉汉数值仿真的限流熔断器暂态计算

Research on Current-limiting Fuse Transient Based on Callahan Numerical Simulation

高压限流熔断器因其限制短路电流能力强、保护性能好而在电力系统中正得到广泛应用,但是熔断器保护动作引起的过电压往往容易对系统设备造成不利影响。为此,基于卡拉汉数值算法着重研究限流熔断器动作过程中的过电压及电流暂态。首先建立了高断力限流熔断器保护动作过程的非线性电阻模型;接着运用半隐格式的卡拉汉数值算法代替EMTP/ATP软件,计算得到了限流熔断器试验回路的熔断器过电压和开断电流波形,数值建模和仿真计算中还综合考虑了其过电压保护MOA避雷器的影响;最后得到了与热效应相关的熔化I2t和合闸相角关系曲线,这对于试验考核熔断器的性能具有指导意义。数值计算与现场实测的比较结果证明,卡拉汉数值算法具有较高的精确性和可靠性,编程实现简便,程序灵活适用,模拟结果准确,可以避免大量现场重复的试验工作,该研究结果对限流熔断器试验可提供实际的参考依据。

High voltage current limiting fuse（CLF） has the advantage of limiting short circuit current and good protection characteristics, therefore it is being more widely used in power system. However, because over-voltage often caused by fuse operation is harmful to the electrical apparatus in power system, this paper deals with current-limiting fuse over-voltage and interruption current during the process of its operation by Callahan numerical algorithm. It is firstly proposed in this paper to construct a non-linear high interruption capacity current-limiting fuse digital model, then the current-limiting fuse circuit transient waveforms is calculated by using Callahan numerical algorithm-a semi-implicit numerical programming method, instead of EMTP/ATP software. Coordination of fuse and MOA protection model is studied to guarantee calculation result correctness. And, the relationship between resulting heat effect I^2 t and switching angle is obtained, which is beneficial to fuse electrical type test. Furthermore, comparison between the calculation and test is carried out to show the accuracy and reliability of this new digital method. It is concluded that numerical analysis by Callahan programming method is much quicker, more flexible and more precise to perform to obtain fuse transient efficiently, leading to get rid of repetitive heavy work on the field test and can provide much practical reference value to CLF practical test.