Capacitive current deteriorates the performance of the current differential protection of ultra high voltage（UHV） transmission line

the conventional capacitance current compensation algorithm compensates the capacitive current

but there are still issues that led to the compensation is not accurate affected by the fault point line failure in the area

so this paper proposes a time-domain capacitance current compensation algorithm based on fault location. The algorithm using fault transient characteristics can compensate transient capacitance current partially

and guarantee the reliability of the current differential protection under the condition of without increasing action current threshold value. Based on 1 000 k V UHV transmission lines with parallel reactor simulation

using this algorithm can compensate capacitance current accurately

and guarantees the reliability of the zone fault

at the same time improves the sensitivity of failure greatly

and proves the correctness and effectiveness of the proposed algorithm

which can be used as a compensation algorithm of UHV transmission line current differential protection.