某电厂厂用6KV电源差动保护误动作原因分析

The Causes and Measuees of 6KV Power System Differential Protection Misstart in Shanxi Aluminium Plant

通过对线路纵差保护工作原理和线路纵差保护不平衡电流的分析，得出引起山西铝厂线路纵差保护误动作的原因是差动继电器的起动值不能躲过外部短路的不平衡电流，并提出提高电流互感器的额定电流，使得相应的电流倍数下降，或采用带制动特性的BCH—1型差动继电器予以解决。

This paper analyese the elements of transmission line Lengthwise differential protection and the imbalance current of transmission Line Lengthwise differential protection,find the causes of transmission line lengthwise differential protection misstart in Shanxi aluminium plant is the start current value of the differential relay don' t avoid the imbalance cur rent in outside fault. And pressents the measures of elecvate the current transformer rated current, reduce corresponding cur rent multiple or adopt brake character BCH-1 differential relay.