It analyses the principle of current TAP and transformer/TA connection compensation of SEL-587 percentage restrained differential element, and discusses the difference between two different SEL-587 trip logic equations.

During the relay experiment,the trip logic order must be checked.

The methods of finding the solutions to logical equation and logical equations;

The author systematically describes the design and the development of the KPS system from aspects of the innovation background,the functional requirements,the design of logical equation,the software architecture and the functions application,and so forth.

Exploration of logic equation F=G s solution;

To simplify mutual exclusive multivariable logic function through logic equation;

The article gives some theories about the relations among solution sets of logic equations ∏from i=1 to m (Fi+■)=1,∏from i=1 to m Fi■=1 and logic equational group {F1=G1, Fm=Gm.

A delay logistic equation is considered.

For the varied and easy solution to the logic equational group,this paper gives the necessary condition to establish the logic equational group made up of zero-one type and non-zero type and non-one type logic equations,and also gives the method to change the logic equational group into zero type and one type logic equations.

The article gives some theories about the relations among solution sets of logic equations ∏from i=1 to m (Fi+■)=1,∏from i=1 to m Fi■=1 and logic equational group {F1=G1, Fm=Gm.