中文摘要：

本文结合传热学相关原理,对高分子PTC电阻在大电流条件下的瞬态限流过程进行建模。建模中假定PTC电阻为绝热状态以及比热容为定值,同时依据PTC电阻的R-T特性曲线,将PTC电阻值分区间进行建模。在大量实验数据的基础上,确定了PTC电阻的比热容,电阻温度系数、材料常数。通过离散差分化处理的求解方法,递推出每个采样点的PTC电阻值、回路电流以及PTC电阻的温度。实验结果与仿真的对比验证了假定以及建模的有效性。该模型可推测计算其它不同短路电流下PTC电阻限流过程及特性,具有很好的工程意义。

英文摘要：

Based on the theory of heat transfer, the transient current limiting process of polymer PTC under high current condition is modeled. The model assumes that the PTC resistance is adiabatic and the specific heat capacity is fixed, and the PTC resistance value is modeled between partitions according to the R-T characteristic curve. On the basis of a large number of experimental data, the heat capacity and temperature coefficient of the PTC resistance, the material constants are determined By solving method of discrete difference processing, the PTC resistance, loop currents and PTC resistance temperature of each sampling point value are deduced By comparing the experimental results with under simulation results, the validity of the modeling assumptions is verified This model can be used to calculate the flow and characteristics of PTC resistance under different short-circuit current, which is of great significance in engineering.