A High-Precision Estimation Method of Harmonic Parameters Based on Compound Iterative Algorithm

Abstract

The invention discloses a high-precision harmonic parameter estimation method based on a composite iterative algorithm. The method comprises the steps as follows: firstly, a harmonic amplitude value is directly calculated by utilizing a three-peak interpolation algorithm, and meanwhile, a harmonic phase is calculated to serve as an initial phase value for composite iteration, then the initial phase value is transmitted to a phase difference correction algorithm to obtain a frequency deviation value by utilizing the phase difference correction algorithm, and the phase difference correction algorithm is combined with a spectral leakage cancellation algorithm so as to obtain a phase value for the first-time iterative computation; circulating iteration is performed between the phase difference correction algorithm and the spectral leakage cancellation algorithm repeatedly until a phase iteration result meeting the error limit requirement is obtained. According to the invention, with the adoption of the three-peak interpolation algorithm, the estimation precision of the harmonic amplitude value is improved, and the phase obtained by utilizing the three-peak interpolation algorithm serves as an initial value, and the phase difference correction algorithm and the spectral leakage cancellation algorithm are combined to construct the composite iterative algorithm, so that the estimation precision of a harmonic phase and frequency is greatly improved.

Description

technical field [0001] The present invention relates to a method for estimating harmonic parameters for stationary periodic signals, specifically a method for estimating high-precision harmonic parameters based on a composite iterative algorithm. This method is used to estimate harmonic amplitude, phase and frequency parameters, and belongs to the power grid Signal harmonic analysis technology field. Background technique [0002] With the development of power electronics technology and the expansion of industrial production, nonlinear loads in power systems are increasing. While the nonlinear load brings huge economic benefits, it also injects a large number of high-order harmonics into the power grid, which increases the content of high-order harmonics in the power grid and aggravates the degree of distortion of electrical signals. Therefore, the harmonic analysis of non-sinusoidal signals has great research significance and practical value for power metering and power qua...

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Problems solved by technology

[0004] Although the three-peak interpolation algorithm has high accuracy for harmonic amplitude estimation, this method only uses the phase information of the largest spectral line to estimate the harmonic phase, and the accuracy is not high

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