The invention provides a method for reducing
time limit combination step progression of distribution network relaying protection, comprising the following steps: 1, realizing
differential protection (DP) between all incoming switches and all outgoing switches in a distribution switching
station or a distribution firewall; and 2.1,, if the DP meets action conditions,
tripping off all the incoming switches without time
delay; 2.2, if the DP does not meet the action conditions, executing
overcurrent criterion on all the outgoing switches: judging whether the
overcurrent I is more than set current Iset, namely I is more than Iset; and if the outgoing switches meet the
overcurrent criterion at some time,
tripping off the outgoing switches. The method is utilized to realize selective actions without time
delay for the relaying protection between two-stage panel switches in the distribution switching
station (or a distribution firewall), thus reducing the
time limit combination step progression of the distribution network relaying protection, and greatly decreasing maintenance
workload of relaying protection personnel. The invention also discloses a device for reducing
time limit combination step progression of distribution network relaying protection.