Givens iteration based Prony analysis method for low frequency oscillation

A technology of low frequency oscillation and analysis method, which can be applied in complex mathematical operations and other directions, and can solve problems such as difficulty in solving equations with characteristic equation coefficients, poor calculation accuracy, and difficulty in solving

Inactive Publication Date: 2016-07-06
DALIAN MARITIME UNIVERSITY
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Problems solved by technology

[0084] At present, when the Prony model is used and the least square method is used to calculate the low-frequency oscillation, the order m of the signal model taken is much larger than the actual order p of the signal model, otherwise the calculation accuracy is very poor
However, when the order m of the signal model is greater than the actual order p of the signal model, the coefficient matrix of the characteristic equation coefficient to solve the equation system is already singular, and the numerical conditions become very poor, which makes the solution difficult, and the order of the signal model is larger than the actual signal model The larger the order, the worse the numerical conditions, and the more difficult it is to solve the characteristic equation coefficient solution equation system
[0085] In the patent application with the application number 201610008988.5, the applicant disclosed the Prony low-frequency oscillation analysis method of residual iteration to reduce the order of the signal model in the extended Prony analysis and improve the numerical stability of solving the characteristic equation coefficients to solve the equation system, but There is still room for further improvement

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  • Givens iteration based Prony analysis method for low frequency oscillation
  • Givens iteration based Prony analysis method for low frequency oscillation
  • Givens iteration based Prony analysis method for low frequency oscillation

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Embodiment Construction

[0161] The present invention will be further described below in conjunction with the accompanying drawings. use figure 1 The flow chart of the low-frequency oscillation analysis of the traditional Prony method and Figure 2-3 The flow chart of the method of the present invention is shown, and the following calculation example signals are analyzed.

[0162] x(t)=10e -0.0311t cos(2π×0.2473t+20°)+2e -0.2652t cos(2π×0.42t+13°)+

[0163] 10e -0.0027t cos(2π×0.423t+110°)+e -0.2936t cos(2π×1.0349t+60°)+(50)

[0164] 1.6e -45.8878t cos(2π×2.4t+10°)

[0165] The above signal contains 5 sinusoidal components, which are equivalent to 10 complex exponential components. When using formula (1) to model the above signal, the actual order p of the signal model is 10. The parameters of the calculation example signal are shown in Table 1.

[0166] Table 1 Parameters of the example signal

[0167]

[0168]

[0169] A value is calculated every 0.1s for the above signal, and a tot...

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Abstract

The present invention discloses a Givens iteration based Prony analysis method for low frequency oscillation, and the analysis method adopts an iterative method to reduce the number of orders of a signal model, and improve numerical stability of calculating a characteristic equation coefficient to solve an equation set. The method comprises the following steps: reading measurement data after filtering; using a singular value decomposition method to calculate the actual number of orders of the signal model; using a Givens iterative method to calculate the characteristic equation coefficient; calculating frequency and an attenuation factor; and calculating amplitude and an initial phase. According to the method disclosed by the present invention, by using a Givens iterative Prony method to analyze low frequency oscillation, the number of orders of the signal model maybe the actual number of orders of the signal model during extended Prony analysis, so that the singular of a coefficient matrix for using the characteristic equation coefficient to solve the equation set is effectively avoided, and the numerical calculation stability is improved; and under conditions of the number of orders of the signal model is the actual number of orders of the signal model, the method disclosed by the present invention has a higher calculated result of low frequency oscillation information than the result calculated by using the conventional Prony method.

Description

technical field [0001] The invention relates to a Prony low-frequency oscillation analysis method of a power system, in particular to a Givens iterative Prony method low-frequency oscillation analysis method. Background technique [0002] When the power system is running, low-frequency oscillations with a frequency of 0.1 Hz to 2.5 Hz will occur due to disturbances, which seriously affect the stability of the power system and endanger the safe operation of the power grid and its related equipment. Therefore, it is necessary to closely monitor the possible low-frequency oscillation phenomenon and deal with it in time to prevent the consequences of destroying the stability of the system. Prony analysis is currently one of the most commonly used and most effective methods for analyzing low-frequency oscillations. By performing Prony analysis on signals, parameters such as amplitude, phase, frequency, and attenuation factors reflecting low-frequency oscillations can be directly ...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06F17/16G06F17/15
CPCG06F17/15G06F17/16
Inventor 姚玉斌李崇吴志良王丹
Owner DALIAN MARITIME UNIVERSITY
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