Power grid dynamic reactive power balance control method and system

Abstract

The invention relates to a power grid dynamic reactive power balance control method and system. The method comprises steps: a system voltage in a power plant, and terminal voltages and terminal currents of all the power generators in the power plant are obtained; power grid node voltages and sensitivity coefficients corresponding to the power grid nodes in a preset scope around the power plant are obtained; when a grounding fault or an interphase short circuit fault happens, deviations of the system voltage and the power grid node voltages are obtained, and the maximum deviation signal is extracted; the maximum deviation signal is subjected to discretization processing according to a step action coefficient, a return coefficient and the sensitivity coefficient, and a system step signal is obtained; the system step signal is corrected according to a terminal voltage of a grid connection generator, a special step signal corresponding to the grid connection generator is obtained, the special step signal is inputted into the corresponding grid connection generator, and stepping of the grid connection generator is carried out. The generator group in the power plant is employed as a reactive power source, provides reactive powers for the power grid fault point together to accelerate fault recovery.

Description

technical field [0001] The invention relates to the technical field of electrical engineering, in particular to a control method and system for dynamic reactive power balance of a power grid. Background technique [0002] When a short circuit or ground fault occurs in the power grid, the grid nodes in the fault area will seriously reduce the grid voltage due to a large amount of reactive power loss and even cause power angle instability, threatening the safe and stable operation of the grid. When the fault point is close to the power plant, the generator excitation regulator in the power plant can sense the short-circuit fault and provide strong excitation to support the maintenance of machine terminal voltage and fault recovery. However, when the fault point is far away from the power plant, because the distance between the fault point and the generator is relatively large, the contact reactance between the two is relatively large, and the terminal voltage drop of the gener...

AI Technical Summary

Problems solved by technology

However, when the fault point is far away from the power plant, because the distance between the fault point and the generator is relatively large, the contact reactance between the two is relatively large, and the terminal voltage drop of the generator is limited, which cannot trigger the strong excitation of the generator excitation regulator in the power plant. When the fault point voltage drops sharply and the power angle increases, if it cannot be restored in time, the scope of the accident will be expanded and the stability of the power grid will be threatened

Images