Internal Model Based Frequency Adaptive Filter Modeling Method

Abstract

The invention discloses a frequency adaptive filter modeling method based on an internal model, and relates to the technical field of signal processing. The method includes the following steps: designing a filter based on the internal model principle; designing a frequency tracking module for real-time calculation or tracking of the actual frequency of the power system; constructing a frequency adaptive filter and frequency tracking module based on the internal model principle filter model. The structure of the filter model established by the method is stable and convergent, and the bandwidth can not be affected by the fluctuation of the measured frequency, so that the filter can still have good response speed while having good frequency selection characteristics.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to an internal model-based frequency adaptive filter modeling method. Background technique [0002] During the operation of an independent power system or an independent grid, in addition to voltage distortion, there will also be system frequency fluctuations or offsets caused by load active power fluctuations. The most commonly used phase-locked loop (SRF-PLL) based on synchronous rotating coordinate system (SRF-PLL), can accurately extract the positive sequence component of the voltage, has good dynamic response speed and small error, but the voltage distortion and frequency fluctuation at the same time In the existing environment, there are contradictions in the selection of the bandwidth of the phase-locked loop filter, and the synchronization effect is poor; the recently proposed double second-order generalized integral phase-locked loop (Double Second Order Generaliz...

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Problems solved by technology

The most commonly used phase-locked loop (SRF-PLL) based on synchronous rotating coordinate system (SRF-PLL), can accurately extract the positive sequence component of the voltage, has good dynamic response speed and small error, but the voltage distortion and frequency fluctuation at the same time In the existing environment, there are contradictions in the selection of the bandwidth of the phase-locked loop filter, and the synchronization effect is poor; the recently proposed double second-order generalized integral phase-locked loop (Double Second Order Generalized Integrator-PLL, DSOGI-PLL), the filter of the three Phase unbalance and harmonic voltage have a good suppression effect, and have frequency adaptive characteristics, but are still affected by frequency fluctuations and voltage amplitude fluctuations, and have large phase errors in the operating environment of independent power grid frequency fluctuations

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