Hotline work technology on substation secondary system;

Study of testing criteria for secondary systems of 110 kV digital substations

The article shows how to build a structure about safeguard system of secondary system in electric power control center in GanXi Region,which can help keeping the electric power network running safely,stably and economically.

Global structure of a class of quadratic system;

Uniqueness of limit cycles of type Ⅲ quadratic system(Ⅰ);

This paper discusses the conditions of the quadratic systems (Ⅱ) δ=0 with second order fine focus.

In this paper,we apply Abelian integrals and complete elliptic integrals of the first,second kinds to study an upper bound on the number of zeros of Abelian integrals for a class of the plane quadratic systems with two centres,under polynomial perturbation of arbitrary degree n.

The new criteria for the uniqueness of limit cycles of the quadratic systems have been given by using the quadratic curve without contact.

Utilizing mechanism analyzing and statistical analyzing methods,a dynamic model of secondary air systems has been constructed and its effectiveness and accuracy validated by simulation.

Design and control strategy of secondary pumping systems;