Method used for online monitoring of low-frequency oscillation of electric power system and based on combination of change-point detection and Prony method

A technology of change point detection and low-frequency oscillation, which is applied in the direction of electrical components, circuit devices, AC network circuits, etc., can solve the problems of unreliable system modal parameter information, inaccurate results, and large amount of calculation, so as to overcome the inaccuracy of actual oscillation Match, improve precision, improve reliable results
CN104953583AActive Publication Date: 2015-09-30HOHAI UNIV +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
HOHAI UNIV
Publication Date
2015-09-30

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Abstract

The invention provides a method used for online monitoring of low-frequency oscillation of an electric power system and based on combination of change-point detection and a Prony method. The method comprises steps as follows: on the basis of a WAMS (wide area measurement system), converting power angle data of all observation units in the system into relative power angle values based on reference units; monitoring abrupt change of relative power angles of the observation units; in response to the abrupt change, constructing a time sequence by the aid of real-time data of relative power angle values; performing change-point detection, and detecting types causing dynamic response of the system; executing set processing in response to different types causing the dynamic response of the system: performing Prony algorithm based system mode analysis, or returning to the former steps for continuously monitoring the abrupt change of relative power angles of the observation units and processing a change-point detection result. With the adoption of the method, the defects of a conventional low-frequency oscillation online monitoring system can be overcome, the low-frequency oscillation state of the system is accurately judged, meanwhile, the influence caused by non-stationary performance of an oscillation starting early signal can be avoided, and the precision and the reliability of system mode information acquired with the Prony method are improved.
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Description

technical field

[0001] The invention relates to the field of low-frequency oscillation monitoring and analysis of power systems, in particular to an online monitoring method for low-frequency oscillations of power systems based on the combination of change point detection and Prony algorithm. Background technique

[0002] At present, low-frequency oscillation has become a prominent problem that limits the power transmission capacity between regions of the interconnected grid and affects the safe and stable operation of the system. The low-frequency oscillation is mainly manifested as the continuous relative swing between the generator rotors due to insufficient damping after the synchronous power system is disturbed, and it is electrically manifested as the continuous oscillation of the generator power angle, tie line power and bus voltage. The frequency is generally between 0.1 and 2.5 Hz. The timely discovery of low-frequency oscillations in the power system and the adopt...

Claims

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