Method for judging negative damping oscillation and force oscillation based on second order difference method

A technology of negative damped oscillation and secondary difference, which is applied in the field of power systems, can solve problems such as negative damped oscillation and forced oscillation methods that have not yet been discovered

Active Publication Date: 2012-08-29
CHINA ELECTRIC POWER RES INST +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to the similarity between the two types of oscillations, there is no report on the method that can effectively distinguish between negatively damped oscillations and forced oscillations.

Method used

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  • Method for judging negative damping oscillation and force oscillation based on second order difference method
  • Method for judging negative damping oscillation and force oscillation based on second order difference method
  • Method for judging negative damping oscillation and force oscillation based on second order difference method

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Embodiment Construction

[0037] The technical problem to be solved by the invention is to quickly and accurately determine whether the oscillation is a negative damped oscillation caused by insufficient system damping or a forced oscillation caused by the existence of a disturbance source when low-frequency oscillation occurs in a power system.

[0038] The technical solution adopted by the present invention to solve its technical problems specifically includes the following parts:

[0039] (1) Electrical quantity characteristics in the process of low-frequency oscillation

[0040] When low-frequency oscillation occurs in the power system, the rotor angle, speed, and related electrical quantities of the generator, such as line power, bus voltage, etc., will undergo oscillations of approximately equal amplitude or increased amplitude, and the oscillation frequency is relatively low, generally between 0.1-2.5 Hz or so.

[0041] Let the angular frequency be ω d The Nth and N+1 amplitudes of the oscilla...

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Abstract

The invention provides a method for judging negative damping oscillation and force oscillation based on a second order difference method. The method comprises the following steps of: 1-, acquiring an actual measurement oscillation curve; 2-, respectively solving a first order difference value and a second order difference value at the maximum time point in each oscillation period; and 3-, comparing symbols of the first order difference value and the second order difference value at the same time, and judging a mode of the oscillation curve according to a comparison result. According to the method for judging the negative damping oscillation and the force oscillation based on the second order difference method, whether certain low frequency oscillation is the negative damping low frequency oscillation caused by the reason that a system is lacking of damping or is the force oscillation caused by a forced disturbance source existing in the system can be rapidly identified in the more than a dozen of initial cycles through the data of a power management unit (PMU) or a wide area measurement system (WAMS), so that a measure of restraining the low frequency oscillation is rapidly taken.

Description

technical field [0001] The invention belongs to the field of power systems, and in particular relates to a method for discriminating negative damped oscillations and forced oscillations based on a quadratic difference method. Background technique [0002] With the deepening of the marketization process of the power industry, the power system is increasingly operating at its limit, and the low-frequency oscillation problem is a common technical problem faced by domestic and foreign power grids. Low-frequency oscillation has low frequency, wide oscillation range, and long oscillation duration, which poses a huge threat to the security and stability of the power grid. There are two main reasons for low-frequency oscillation. One is negative damping low-frequency oscillation. Negative damping oscillation is a process of gradual increase in amplitude. If there is no human intervention, the amplitude of oscillation will continue to increase. Instability; the other is low-frequenc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/00
Inventor 刘增煌李莹李文锋陶向宇王官宏何凤军濮钧朱方
Owner CHINA ELECTRIC POWER RES INST
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