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Harmonic

About: Harmonic is a research topic. Over the lifetime, 44833 publications have been published within this topic receiving 495922 citations. The topic is also known as: overtone & partial.


Papers
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Journal ArticleDOI
TL;DR: A new desynchronized processing technique for harmonic and interharmonic analysis that has general validity and results fully compatible with the IEC standard is presented and is as accurate as those of synchronized techniques.
Abstract: A new desynchronized processing technique for harmonic and interharmonic analysis that has general validity and results fully compatible with the IEC standard is presented This technique is based on a double-stage signal processing procedure: In the first stage, the harmonic components are accurately estimated via interpolations in frequency domain and filtered away from the original signal so that in the second stage, interharmonics can be evaluated without the spectral leakage due to harmonic tones Since the procedure does not require synchronization, it allows adopting a fixed sampling frequency and, at the same time, the direct use of fast Fourier transform on the acquired samples, thereby reducing the computational burden The procedure is successfully applied to both numerical tests and onfield measurements The obtained results are as accurate as those of synchronized techniques

118 citations

Journal ArticleDOI
TL;DR: In this paper, an adaptive harmonic steady-state (ADHSS) algorithm combined with a magnitude/phase locked-loop (MPLL) frequency estimator is proposed for sinusoidal disturbances of unknown frequency acting at the output of unknown plants.
Abstract: This paper is concerned with the rejection of sinusoidal disturbances of unknown frequency acting at the output of unknown plants. Disturbance rejection is based on an adaptive harmonic steady-state (ADHSS) algorithm combined with a magnitude/phase locked-loop (MPLL) frequency estimator. The harmonic steady-state method assumes that the plant can be approximated by its steady-state frequency response. For high-order plants such as those encountered in active noise and vibration control (ANVC), this assumption greatly reduces the number of parameters and enables online estimation of the plant response using simple algorithms. The paper shows that when the MPLL is integrated with the ADHSS algorithm, the two components work together in such a way that the control input does not prevent frequency tracking by the MPLL, and so that the order of the ADHSS can be reduced. Thus, the addition of the MPLL allows disturbances of unknown frequency to be considered without significantly increasing the complexity of the original ADHSS. After analyzing the reduced-order ADHSS in the ideal case, the equations describing the complete system are considered. The theory of averaging is used to gain insight into the steady-state behavior of the algorithm. It is found that the system has a two-dimensional equilibrium surface such that the disturbance is cancelled exactly. A subset of the surface is proved to be locally stable. Extensive active noise control experiments demonstrate the performance of the algorithm, even when disturbance and plant parameters are changing.

118 citations

Journal ArticleDOI
TL;DR: In this article, the authors considered rigidly coupled rotors mounted on idealised linear bearings and derived an expression for the magnitude and phase of the response at twice synchronous speed.

117 citations

Journal ArticleDOI
TL;DR: In this article, a 2.45 GHz fully differential CMOS power amplifier with high efficiency and linearity is presented, where an optimum gate bias is applied for the cancellation of the nonlinear harmonic generated by g/sub m3/ and a new harmonic termination technique at the common source node along with normal harmonic termination at the drain.
Abstract: A 2.45 GHz fully differential CMOS power amplifier (PA) with high efficiency and linearity is presented. For this work, a 0.18-/spl mu/m standard CMOS process with Cu-metal is employed and all components of the two-stage circuit except an output transformer and a few bond wires are integrated into one chip. To improve the linearity, an optimum gate bias is applied for the cancellation of the nonlinear harmonic generated by g/sub m3/ and a new harmonic termination technique at the common source node is adopted along with normal harmonic termination at the drain. The harmonic termination at the source effectively suppresses the second harmonic generated from the input and output. The amplifier delivers a 20.5dBm of P/sub 1dB/ with 17.5 dB of power gain and 37% of power-added efficiency (PAE). Linearity measurements from a two-tone test show that the power amplifier with the second harmonic termination improves the IMD3 and IMD5 over the amplifier without the harmonic termination by maximally 6 dB and 7 dB, respectively. Furthermore, the linearity improvements appear over a wide range of the power levels and the linearity is maintained under -45 dBc of IMD3 and -57dBc of IMD5 when the output power is backed off by more than 5dB from P/sub 1dB/. From the OFDM signal test, the second harmonic termination improves the error vector magnitude (EVM) by over 40% for an output power level satisfying the 4.6% EVM specification.

117 citations

Journal ArticleDOI
TL;DR: Experimental results on plant configurations with multiple PV inverters show that low- order harmonics sum up almost arithmetically, whereas the higher-order harmonics and the interharmonics sum up in an almost Euclidean way.

117 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,223
20222,724
20211,878
20202,330
20192,612
20182,495