Sub-synchronous oscillation analysis method combining PRONY and FFT algorithms

Abstract

The invention discloses a sub-synchronous oscillation analysis method combining PRONY and FFT algorithms. The method comprises the following steps of: (1) obtaining transient recording data from a sub-synchronous oscillation monitoring main station, and calculating the instantaneous power of monitoring equipment according to three-phase instantaneous voltage and instantaneous current, (2) performing oscillation mode analysis on the instantaneous power data by using a PRONY algorithm, and positioning oscillation starting and ending time to obtain sub-synchronous oscillation characteristics, (3)carrying out FFT on the instantaneous current within the period of time according to the oscillation starting and ending time positioned in the step (2), and accurately calculating the frequency, amplitude, component and other information of the simple harmonic current during sub-synchronous oscillation, and (4) performing comprehensive statistics on the analysis result to generate an event briefreport, and displaying the result. The method can be used for carrying out sub-synchronous oscillation analysis on a large amount of transient recording data, the efficiency of sub-synchronous oscillation automatic analysis is improved, and rapid and accurate identification of sub-synchronous oscillation is achieved.

Description

technical field [0001] The invention belongs to the field of power system automation, and in particular relates to a method for performing subsynchronous oscillation analysis on a large amount of transient wave recording data. Background technique [0002] In recent years, with the continuous expansion of the scale of the power system, the grid-connected operation of large-scale new energy power plants and the application of a large number of power electronic equipment have brought new challenges to the operation of the power system. The phenomenon of subsynchronous oscillation induced by wind farms has occurred many times in the Hami area of ​​Xinjiang, and has affected the surrounding thermal power units, which has had a negative impact on the safe and stable operation of the power grid. [0003] Subsynchronous oscillation is a serious system stability problem. It will not only cause the system to oscillate, but also easily cause damage to the large shaft of the turbo-gene...

AI Technical Summary

Problems solved by technology

The phenomenon of subsynchronous oscillation induced by wind farms has occurred many times in the Hami area of ​​​​Xinjiang, affecting the surrounding thermal power units, which has a negative impact on the safe and stable operation of the power grid

[0003] Subsynchronous oscillation is a serious system stability problem. It will not only cause the system to oscillate, but also easily cause damage to the large shaft of the turbo-generator set. At present, the cause and mechanism, monitoring and control of subsynchronous oscillation are still under study.

At present, the traditional signal analysis method is generally used for subsynchronous oscillation analysis, which has few analysis methods and low efficiency, and cannot meet the analysis needs of a large amount of transient recording data.

[0004] Traditional signal analysis methods have limitations. For example, the FFT algorithm can only give the frequency distribution of the signal, but cannot give the frequency change with time. For non-stationary signal analysis, it lacks the time positioning function

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