A Subsynchronous Oscillation Analysis Method Combining Prony and FFT Algorithms

Abstract

The invention discloses a sub-synchronous oscillation analysis method combining PRONY and FFT algorithm, which includes the following steps: (1) Obtain transient wave recording data from the sub-synchronous oscillation monitoring master station, and calculate the monitoring equipment according to the three-phase instantaneous voltage and instantaneous current (2) Use the PRONY algorithm to analyze the oscillation mode of the instantaneous power data, locate the start and end time of the oscillation, and obtain the characteristics of the subsynchronous oscillation; (3) locate the start and end time of the oscillation according to step (2), for Perform FFT on the instantaneous current during this period to accurately calculate the frequency, amplitude, component and other information of the simple harmonic current during subsynchronous oscillation; (4) Make comprehensive statistics on the analysis results, generate event briefings, and display the results. This method can be used for subsynchronous oscillation analysis on a large amount of transient wave recording data, improves the efficiency of automatic analysis of subsynchronous oscillation, and realizes fast and accurate identification of subsynchronous oscillation.

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...

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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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