The calculating process of differential variable and restrained variable on differential restrained curve are introduced,and the necessity of filtering zero part is analyzed.

The correctness demonstrating of microprocessor transformer differential protection loop current balance mode;

Improvement of ultra high voltage transformer differential protection;

Differential Eddy-current Type Continuous-casting Mould Molten Steel Level Meter;

Aim for the problem that producing gears exist precision low and error big in practical produce,passed to technically regenerate to differential hanging gears of primeval equipment(Y320 roll-gear machinery),improved some big module-small spiral angle gears of producing quantity,attained to user requirement,and received the satisfactory economic performance.

In this paper,computer technology is applied to solve the problem that exist in selecting the differential hanging gears,such as database generation、hanging gears finding and big error of traditional calculation method,and to improve the precision and speed of finding differential hanging gears,and to satisfy the needs of actual processing.

Application of differential gear train in extended step-less speed variation range;

Design of the speed shifting mechanism of differential gear train;

The transmission system mainly consists of differential gear train,planetary gear train,crank linkage slide mechanism and two drive motors.

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;