Out-of-step and oscillation center positioning and migration tracking system and method under multi-frequency oscillation

Abstract

The invention belongs to the technical field of stability analysis of power systems and particularly relates to a position function-based out-of-step and oscillation center positioning and migration tracking system and method under multi-frequency oscillation. The method comprises the steps of connecting power supplies at three sides to a point through three lines to build a three-machine equivalent system model; obtaining a voltage vector expression of any point under the simultaneous action of the power supplies at three sides according to a superposition theorem; setting position functionsof oscillation centers according to line impedance ratios; rewriting the voltage vector expression of any point into a form of modulus and phase, expanding the expression into a quadratic function, calculating a partial derivative and then obtaining an expression of the position of the oscillation center at any side according to a trigonometric function relationship and a mean value inequality; and analyzing the influences of three factors, namely relative power angles of systems, impedance structure parameters and power supply voltage amplitudes of the systems on the oscillation centers, obtaining conditions of appearing of an out-of-step center at various sides, obtaining a criterion according to the trigonometric function relationship of one voltage vector and then determining the position of the out-of-step center.

Description

technical field [0001] The invention belongs to the technical field of power system stability analysis, and in particular relates to a multi-frequency oscillation out-of-step oscillation center positioning and migration tracking system and method based on a position function. Background technique [0002] With the development of my country's UHV interconnected power grid and the access of a large number of new energy sources, the scale of the power system is expanding day by day, and the operation mode of the system is changing. At the same time, the system oscillation presents the characteristics of complex causes and changeable modes. The oscillation center may not be on a certain fixed line, but may dynamically migrate on different lines, which brings severe challenges to the oscillation identification of power system safety and stability devices. . [0003] At present, the analysis and research on oscillation characteristics at home and abroad are mostly based on the tw...

AI Technical Summary

Problems solved by technology

However, in the multi-frequency oscillation scenario, the above-mentioned analysis method based on the two-machine model is no longer applicable, and the oscillation characteristics based on the two-machine model are difficult to describe the actual situation of multi-frequency oscillation

There are few reports on out-of-step oscillation center location methods in multi-frequency oscillation scenarios

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