Base wave and harmonic detecting method based on Nuttall window double peak interpolation FFT

An interpolation and harmonic technology, applied in the field of signal processing, can solve problems such as spectrum leakage, fundamental wave and harmonic measurement and analysis are difficult to achieve

CN101113995AInactive Publication Date: 2008-01-30HUNAN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2008-01-30
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a fundamental wave and harmonic detection method based on a Nuttall window bimodal interpolation FFT (Fast Fourier Transform): a measured signal is carried out the modulus conversion and the low-pass filter wave processing, the signal is operated adding windows by adopting the low side petal voltage and rapid attenuation speed Nuttall window, the bimodal interpolation arithmetic is used for detecting the fundamental wave and the harmonic in the detected signal. The invention comprises the aspects of: (1) modulus conversion and digital low-pass filter wave; (2) FFT operation based on the Nuttall window; (3) bimodal interpolation and polynomial fitting to solve the fundamental wave and harmonic parameters.
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Description

Technical field

[0001] The invention relates to a method for detecting fundamental wave and harmonic parameters in signals. Specifically, it is a fundamental wave and harmonic parameter detection method based on Nuttall window bimodal interpolation FFT (Fast Fourier Transform), which belongs to the technical field of signal processing and can also be used for harmonic analysis of other signals. Background technique

[0002] Taking power signal detection as an example, with the development of power electronics technology, non-linear devices are widely used in power systems, and the harmonic problems brought by non-linear devices pose an increasingly serious threat to the safety, stability and economic operation of power systems. Accurate measurement of fundamental and harmonics can provide scientific basis for power grid energy metering, harmonic power flow calculation, equipment network detection, power system harmonic compensation and suppression, etc.

[0003] Fundamental...

Examples

Embodiment Construction

[0052] The invention proposes a fundamental wave and harmonic wave detection method based on Nuttall window bimodal interpolation FFT. The following will be described in detail in conjunction with the accompanying drawings, but not as a limitation of the present invention.

[0053] This embodiment is a harmonic parameter detection part of a three-phase multifunctional harmonic electric energy meter that can be used to measure harmonic electric energy in a power system.

[0054] Set the maximum number of harmonic detection in this embodiment to 21 times, the analog-to-digital converter adopts the 71M6513 produced by TDK Company, and the CPU adopts the BF533 processor produced by ADI Company, and the main parameters are selected as follows:

[0055] (1) Sampling rate: f s = 2520;

[0056] (2) Power grid fundamental frequency: fluctuates around 50Hz;

[0057] (3) FFT operation data length: N=512.

[0058] The processing flow diagram of the present embodiment is shown in Figur...