中文摘要：

国家军用标准（GJB-173）计算法在计算船舶短路电流时，为求计算简便忽略较多，导致计算结果偏大，这给配置船舶电力系统保护和设备选型带来很大困难。为提高准确性，考虑发电机短路电流周期分量的超瞬态衰减，考虑短路发生在远离汇流排位置时线路阻抗的影响，并对周期分量衰减时间常数进行修正；用平方根法求平均等效电动机功率及衰减时间常数，电动机馈送的短路电流等于所有平均等效电机短路电流之和，针对GJB-173算法产生误差的原因对算法进行改进。结合算例，进行仿真验证，仿真结果表明改进算法具有较高的准确性和精度，可以在较准确计算短路电流的基础上，有效的减小计算结果中的正误差。

英文摘要：

The GJB-173 algorithm has a large error, which brings troubles to setting protection disposition, and selecting appropriate devices. In order to get more accurate short-circuit current values, an improved algorithm is introduced, in which the periodic current sub-transient attenuation of generator is taken into consideration, and the decay time constant is corrected in view of the line impedance when the short-circuit point is away from the bus-bar. The average equivalent motor power and decay time constant are figured out by root-squaring method, and the motor short-circuit current is sum of all the average equivalent motors＇. Finally a power system is provided, and compared with GJB-173 and GB-3321 the calculation results of improved algorithm are proved to have higher accuracy and fewer errors.