Non-characteristic harmonics and interharmonics of power electronic converters

Kus, Vaclav; Peroutka, Zdeněk; Drabek, Pavel

doi:10.1049/cp:20051030

Cited by 13 publications

(5 citation statements)

References 3 publications

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“…Interharmonics mainly originate from nonperiodic changes in current and voltage caused by loads operating in nonsteady states and/or amplitude modulation in control strategies [4]. Several factors contribute to their generation, including the use of nonlinear loads, double conversion systems, cascaded subsynchronous converters [5,6], asymmetric induction motors and the incorporation of AC/DC and DC/AC conversions in renewable energy sources such as photovoltaic systems [7][8][9] and wind turbines [10,11]. Additionally, double-stage systems, which consist of two AC systems operating at different frequencies interconnected through a DC link [12,13], have also been identified as significant sources of interharmonics.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Interharmonics Generation in Induction Motors Driven by Variable Frequency Drives and AC Choppers

Gudiño-Ochoa,

Jalomo-Cuevas,

Molinar-Solís

et al. 2023

Energies

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In modern power systems, interharmonics have emerged as noninteger frequency components that appear in current or voltage signals. Double-stage AC-DC-AC converters have been identified as a primary source of interharmonics. Previous studies have highlighted modulation techniques, filters, passive components, unbalanced conditions and DC link effects as relevant factors. However, the interaction between these factors and the inertial properties of induction motors has not been explored. This study assesses various types of AC drives, including variable frequency drives (VFDs) and soft starters (AC choppers), to investigate their interaction with machine inertial properties in interharmonic generation. The employed technique for time-frequency spectral analysis is the wavelet synchrosqueezed transform combined with a clustering method. This paper demonstrates that the interaction of the inertial properties of low-power induction motors with the variations of the switching frequencies of the VFDs, the filters used in the DC link and a soft start indirectly contribute to harmonic generation and potentially to interharmonics in the electrical grid and the outputs of the inverter.

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Section: Introductionmentioning

confidence: 99%

Analysis of Interharmonics Generation in Induction Motors Driven by Variable Frequency Drives and AC Choppers

Gudiño-Ochoa,

Jalomo-Cuevas,

Molinar-Solís

et al. 2023

Energies

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“…If many disturbance sources occur, then the identification of individual disturbing loads on the basis of one period of simultaneous measurements is possible only after eliminating the main source of disturbances. Moreover, the current solutions proposed in the literature do not allow for the identification of sources of voltage fluctuations that change their operating state with a frequency greater than the power frequency f c [29,30] (e.g., power electronic devices [31][32][33][34][35]). These disturbance sources can cause an obnoxious flicker, because in the demodulation process of the IEC flickermeter, the components of the modulating signal with the frequency f i in the band from f c to 3 f c (associated with the disturbance source) become components of the flicker with the frequency 2 f c − f i .…”

Section: Introductionmentioning

confidence: 99%

Selective Identification and Localization of Voltage Fluctuation Sources in Power Grids

Kuwałek¹

2021

Energies

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The current study presents a novel approach to the selective identification and localization of voltage fluctuation sources in power grids, considering individual disturbing loads changing their state with a frequency of up to 150 Hz. The implementation of the proposed approach in the existing infrastructure of smart metering allows for the identification and localization of the individual sources of disturbances in real time. The proposed approach first performs the estimation of the modulation signal using a carrier signal estimator, which allows for a modulation signal with a frequency greater than the power frequency to be estimated. In the next step, the estimated modulating signal is decomposed into component signals associated with individual sources of voltage fluctuations using an enhanced empirical wavelet transform. In the last step, a statistical evaluation of the propagation of component signals with a comparable fundamental frequency is performed, which allows for the supply point of a particular disturbing load to be determined. The proposed approach is verified in numerical simulation studies using MATLAB/SIMULINK and in experimental studies carried out in a real low-voltage power grid. The research carried out shows that the proposed approach allows for the selective identification and localization of voltage fluctuation sources changing their state with a frequency of up to 150 Hz, unlike other methods currently used in practice.

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“…In the case of light sources, flicker can occur [8]- [10], which in bad conditions can induce epileptic or depressive states. The scale of the problem of voltage fluctuations increases with the development trend of modern power systems, which are focused on increasing the share of renewable energy sources in the manufacturing sector [11]- [13] and at increasing the number of power electronic loads [14], [15], e.g. working with renewable energy sources, or used in energy-saving solutions, or used in control systems.…”

Section: Introductionmentioning

confidence: 99%

Wpływ wartości skutecznej sygnału na dokładność pomiaru zawartości harmonicznych

Kuwałek¹,

Otomański²

2017

PUT Academic J.: Electrical Engineering

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The paper presents an innovative approach to the identification of sources of voltage fluctuations in power networks, also considering the localization understood as the indication of supply points of disturbing loads. The presented approach considers disturbance sources that change their operating state with a frequency higher than the power frequency. Implementation of the proposed solution is also proposed in such a way that its implementation in the smart meter infrastructure allows for automatic localization of disturbance sources without additional expert knowledge. In the proposed approach, the modulation signal is estimated using a carrier signal estimator, which allows for the estimation of modulation signal with a frequency higher than the power frequency. The estimated modulating signal is decomposed into component signals associated with individual disturbing loads by decomposition by approximation using pulse waves. The decomposition process allows for the estimation of selected parameters associated with disturbing loads, on the basis of which the assessment of propagation of voltage fluctuations associated with the impact of individual disturbance sources is performed, which allows for the indication of their supply point. The proposed approach was verified in numerical simulation studies using MATLAB/SIMULINK and in experimental studies carried out in a real low-voltage power grid.

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Non-characteristic harmonics and interharmonics of power electronic converters

Cited by 13 publications

References 3 publications

Analysis of Interharmonics Generation in Induction Motors Driven by Variable Frequency Drives and AC Choppers

Analysis of Interharmonics Generation in Induction Motors Driven by Variable Frequency Drives and AC Choppers

Selective Identification and Localization of Voltage Fluctuation Sources in Power Grids

Wpływ wartości skutecznej sygnału na dokładność pomiaru zawartości harmonicznych

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