An effective power flow calculation method after line-off based on breaking function

Quickly finding the voltage value of each node is the basis for judging the voltage exceedance degree when the power system is opened and broken. In this paper, a fast calculation method of line opening voltage based on breaking function is proposed. Firstly, a reference variable is introduced on the admittance of the broken line, and a nonlinear opening function about the reference variable is constructed, so that the voltage are functions about the correlative reference variables after the line is opened. Then, by using the Taylor series expansion, the voltage of each node before the opening is taken as the original value of the Taylor series, and the first, second and third derivatives about the voltage regarding the reference variables are taken as the right term. The voltage of the system each node is calculated after the line is opened or broken. Finally, the feasibility of the suggested method is certified in IEEE 14-node system.