Some special functional requirements on line protection in related codes are analyzed;the configuration of T-zone protection,the synchronizing method of reclosing as well as the design concept and working principle of transferred tripping circuit are expounded.

Analysis of maloperation of generator differential protection caused by transient unbalanced current;

Analysis of mal-operation of transformer differential protection;

Analysis and solution of misoperation of transformer differential protection when external ground fault occurs;

Communication clock setup in the current differential protection based on optic fiber;

Analysis on the transformer differential protection acting in error and the treatment;

Job elements in vertical differential protect of electric transformer and protect bound in course of electric transformer are introduced.

Compensating measure of transient capacitive current of UHV transmission line on differential current protection;

Abatract: Based on the study about the influence of the distributed capacitance current of UHV transmission line on differential current protection,a principle which is free from capacitance current impact is put forward in this paper.

Based on the study about the influence of the distributed capacitance current of UHV transmission line on differential current protection, a novel accurate compensation method of capacitance current is proposed.