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  • 1.
    Alfieri, Luisa
    et al.
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Bracale, Antonio
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Carpinelli, Guido
    Department of Electrical Engineering and Information Technology, University of Naples Federico II.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    A Wavelet-Modified ESPRIT Hybrid Method for Assessment of Spectral Components from 0 to 150 kHz2017Inngår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, nr 1, artikkel-id 97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Waveform distortions are an important issue in distribution systems. In particular, the assessment of very wide spectra, that include also components in the 2-150 kHz range, has recently become an issue of great interest. This is due to the increasing presence of high-spectral emission devices like end-user devices and distributed generation systems. This study proposed a new sliding-window wavelet-modified estimation of signal parameters by rotational invariance technique (ESPRIT) method, particularly suitable for the spectral analysis of waveforms that have very wide spectra. The method is very accurate and requires reduced computational effort. It can be applied successfully to detect spectral components in the range of 0-150 kHz introduced both by distributed power plants, such as wind and photovoltaic generation systems, and by end-user equipment connected to grids through static converters, such as fluorescent lamps.

  • 2.
    Alfieri, Luisa
    et al.
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Bracale, Antonio
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Carpinelli, Guido
    Department of Electrical Engineering and Information Technology, University of Naples Federico II.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Accurate assessment of waveform distortions up to 150 kHz due to fluorescent lamps2017Inngår i: 2017 6th International Conference on Clean Electrical Power: Renewable Energy Resources Impact, ICCEP 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 636-644, artikkel-id 8004756Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Fluorescent lamps are among the most diffuse electrical components that introduce significant waveform distortions in low voltage distribution systems. These distortions involve a wide range of frequencies (i.e., from 0 kHz to 150 kHz), and spectral components characterized by a non-uniform behavior in time and frequency domains. Early IEC standards covered formally only the range from 0 kHz to 9 kHz, defining grouping and group total harmonic distortion both for the low-frequencies (i.e., from 0 kHz to 2 kHz) and for frequencies ranging from 2 kHz to 9 kHz. Recently, the IEC standards have suggested to extend the grouping, previously defined for the range from 2 kHz to 9 kHz, also to the range from 9 kHz to 150 kHz. In this paper, the waveform distortions of a variable number of fluorescent lamps were quantified by applying the main Power Quality indices currently available for such devices. Indices are evaluated using both the IEC method and an hybrid method proposed recently in the relevant literature, i.e., the sliding-window Wavelet-Modified ESPRIT method. Numerical applications on measured data show the waveform distortion levels versus the number of lamps, quantifying also the different performances of the aforesaid spectral analysis methods

  • 3.
    Alfieri, Luisa
    et al.
    Department of Electrical Engineering and Information Technology, University of Naples Federico II, Italy.
    Bracale, Antonio
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    New Power Quality Indices for the Assessment of Waveform Distortions from 0 to 150 kHz in Power Systems with Renewable Generation and Modern Non-Linear Loads2017Inngår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, nr 10, artikkel-id 1633Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The widespread use of power electronics converters, e.g., to interface renewable generation systems with the grid or to supply some high-efficiency loads, has caused increased levels of waveform distortions in the modern distribution system. Voltage and current waveforms include spectral components from 0 kHz to 150 kHz, characterized by a non-uniform time-frequency behavior. This wide interval of frequencies is currently divided into "low-frequency" (from 0 kHz to 2 kHz) and "high-frequency" (from 2 kHz to 150 kHz). While the low-frequencies have been exhaustively investigated in the relevant literature and are covered by adequate standardization, studies for the high-frequencies have been addressed only in the last decade to fill current regulatory gaps. In this paper, new power quality (PQ) indices for the assessment of waveform distortions from 0 kHz to 150 kHz are proposed. Specifically, some currently available indices have been properly modified in order to extend their application also to wide-spectrum waveforms. In the particular case of waveform distortions due to renewable generation, numerical applications prove that the proposed indices are useful tools for the characterization of problems (e.g., overheating, equipment malfunctioning, losses due to skin effects, hysteresis losses or eddy current losses) in cases of both low-frequency and high-frequency distortions

  • 4.
    Andersson, Marcus
    et al.
    Luleå tekniska universitet.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Larsson, Anders
    Wahlberg, Mats
    Bollen, Math
    Interfering signals and attenuation: potential problems with communication via the power grid2006Inngår i: Proceedings of Nordic Distribution and Asset Management Conference: NORDAC 2006, 2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper will give a general overview of the potential problems associated with remote-meter reading via the power grid and describe some of the technologies available. A comparison will be made between the power grid as a communication channel and other, dedicated and shared, channels. Examples will be given of practical cases in which the communication channel does not function in the intended way.

  • 5.
    Beek, Jaap van de
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Eriksson, Mats
    Arctos Labs Scandinavia AB.
    Can Solar Power Help Providing Broadband Cellular Coverage in Extreme-Rural Sweden?2016Rapport (Annet vitenskapelig)
  • 6.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Olofsson, Magnus
    Elforsk.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Standards for supraharmonics (2 to 150 kHz)2014Inngår i: IEEE Electromagnetic Compatibility Magazine, ISSN 2162-2264, Vol. 3, nr 1, s. 114-119Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is a serious interest from the international standard-setting community in knowledge about voltage and current distortion in the frequency range 2 to 150 kHz, referred to as supraharmonics. At the same time, research is ongoing at a number of locations, but the knowledge about supraharmonics remains limited. This paper compares some of the properties of harmonics and supraharmonics. An increase in supraharmonics for individual devices is observed in association with a decrease in harmonic emission (i.e. below 2 kHz). A proposal is made for setting limits in this frequency range. The proposal is based on existing standards and is meant to be for discussion. The authors strongly encourage an open discussion about the proposed limits. There are a number of differences between harmonics and supraharmonics that are not covered by the proposed set of limits. A substantial amount of further research is needed to extend the standard framework for supraharmonics such that this can be covered by standards

  • 7.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ribeiro, Paulo
    Calvin College, Grand Rapids, MI.
    Larsson, Anders
    Lundmark, Martin
    Limits for voltage distortion in the frequency range 2 to 9 kHz2008Inngår i: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 23, nr 3, s. 1481-1487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper addresses voltage distortion in the frequency range 2 to 9 kHz, above what is normally considered in harmonic studies. By extrapolating the voltage-distortion limits that exist in international standards for distortion up to 2 kHz, it is concluded that 0.5% of nominal voltage per 200-Hz band is a safe limit. This limit is next used to estimate the number of small generator units (1-10 kW) that can be connected to a low-voltage grid. It is concluded that in some cases the connection of one or just a few units already leads to a distortion level above the limit.

  • 8.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Harmonic emission from installations with energy-efficient lighting2011Inngår i: Proceeding of the International Conference on Electrical Power Quality and Utilisation, EPQU, Piscataway, NJ: IEEE Communications Society, 2011, s. 797-802Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the results from a number of measurements of the harmonic emission from installations that contain a large number of energy-efficient lamps. Two of the measurements concern the replacement of incandescent lamps with CFL and LED; the other measurement concerns an installation with up to 48 fluorescent lamps with high-frequency ballasts. The paper also contains a discussion on why the (total) power factor is not a good measure to quantify the performance of lamps or installations containing large numbers of lamps

  • 9.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sollerkvist, Frans
    Larsson, Anders
    Lundmark, Martin
    Limits to the hosting capacity of the grid for equipment emitting high-frequency distortion2006Inngår i: Proceedings of Nordic Distribution and Asset Management Conference: NORDAC 2006, 2006Konferansepaper (Fagfellevurdert)
  • 10.
    Busatto, Tatiano
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Abid, Fahim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Singh, Gaurav
    Department of Electrical and Computer Engineering, Clemson University.
    Interaction between Grid-Connected PV systems and LED Lamps: Directions for Further Research on Harmonics and Supraharmonics2016Inngår i: 2016 17th International Conference on Harmonics and Quality of Power, Piscataway, NJ, 2016, s. 193-197, artikkel-id 7783479Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper discusses different approaches to investigate the interaction through harmonics, interharmonics, supraharmonics, and light flicker, between photovoltaic (PV) inverters and LED lamps in low-voltage installations. Single grid-connected power generators and electronic loads like LED lamps can be easily characterized in terms of harmonics in a given range of frequency. This subject is relatively well understood, and specific standards for measuring and restricting emissions are already established to ensure a low probability of interference. However, when connected together, source and load exhibit behavior that requires further study and understanding. This work presents a discussion serving as a guide for future work on analysis of losses and other impacts of the disturbances regarding this specific load and source interaction. The following are taken into account: the nonlinearity of LED loads and PV converters; the technologies and methods used in control; and the changes in power flow caused by load and power production variations

  • 11.
    Busatto, Tatiano
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Including Uncertainties from Customer Connections in Calculating Low-Voltage Harmonic Impedance2019Inngår i: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 34, nr 2, s. 606-615Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method is proposed in this paper to determine the harmonic impedances in low-voltage networks in a stochastic way. The consequences of resonances for harmonic propagation and stability of power converters are summarized. By using Monte Carlo simulation, the method includes the uncertainties in customer impedances, specifically due to electronic loads and local generation. The uncertainty in customer impedance is included by considering probability distribution for the resistive, inductive and capacitive parts of the impedance. The concept of transfer impedance is used for phase-to-neutral connections. A method is developed and applied to two existing low-voltage networks in Sweden. Results show that, for these two networks, the resonant frequencies decrease around 28 % once PV panels are installed. The paper includes a discussion of some of the practical aspects of applying the proposed method.

  • 12.
    Busatto, Tatiano
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Supraharmonics Emission Assessment of Multi-level Converters Applied for Photovoltaic Grid-Connected Inverters2017Inngår i: The Renewable Energies and Power Quality Journal (RE&PQJ), ISSN 2172-038X, E-ISSN 2172-038X, Vol. 1, nr 15, s. 143-148, artikkel-id 252Artikkel i tidsskrift (Fagfellevurdert)
  • 13.
    Busatto, Tatiano
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ravindran, Vineetha
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Estimation of the Consumer Electronics Capacitance for Harmonic Resonance Studies by a Non-Invasive Measurement Method2018Inngår i: Proceedings of International Conference on Harmonics and Quality of Power, ICHQP, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2018, , s. 6Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Harmonic resonances in distribution systems are mainly between network inductances and shunt capacitances from capacitor banks and consumer loads. In this paper, particular attention is devoted to the evaluation of capacitances from domestic equipment, serving as a reference for resonance frequency studies. The assessment is performed by simulation and measurements of common low power electronic loads. From the analysis of EMI filters topologies used in AC/DC converters, a non-invasive capacitance measurement estimation method is presented. The method is verified after correlating capacitances with the resonance frequencies obtained from a frequency sweep method. From experimental measurements, the results show that the equivalent shunt capacitances for a set of 24 LED lamps are between 10 and 135 nF.

  • 14.
    Gil-de-Castro, A.
    et al.
    Department of Computer Architecture, Electronics and Electronic Technology, University of Cordoba.
    Moreno-Munoz, A.
    Department of Computer Architecture, Electronics and Electronic Technology, University of Cordoba.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rosa, J.J.G. de la
    Department of Electronics, University of Cadiz.
    LED street lighting: a power quality comparison among street light technologies2013Inngår i: Lighting Research and Technology, ISSN 1477-1535, E-ISSN 1477-0938, Vol. 45, nr 6, s. 710-728Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High-pressure sodium lamps are currently the main lamps used in public lighting. However, the possibility of using high-power light emitting diode (LEDs) for street lighting is growing continuously due to their greater energy efficiency, robustness, long life and light control. The aim of this paper is to study the power quality of high-power lighting networks based on LED and high-pressure sodium lamps. Both electromagnetic and dimmable electronic ballasts, which can dim the lamp output smoothly and uniformly, have been used connected to high-pressure sodium lamps. High-pressure sodium lamps connected to electronic equipment have been tested with different arc power levels using dimming on a 230 V power supply. The study presented in this paper is completely based on measurements, including harmonic currents in the frequency range up to 150 kHz for all the technologies. The main results show a broadband spectrum in LED lamps which confirms other research in fluorescent lamps powered by high-frequency ballasts. Results also indicate a decrease in the harmonic value with increasing harmonic order, and a decrease in the harmonic value at half load (60%) compared with full load (100%). Although total harmonic distortion of the current is lower with high-pressure sodium lamps connected to electronic rather than electromagnetic ballasts, LED lamps achieved the lowest total harmonic distortion of curren

  • 15.
    Gil-de-Castro, Aurora
    et al.
    University of Cordoba.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    LED lamps under different EMC environnments2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    More and more loads are currently connected at the same connection point in industrial, commercial and residential sectors. This paper studies the interaction between a certain LED lamp connected to different industrial environments, and how different LED lamps behave in the same industrial environment. Harmonic emission as well as supraharmonic emission have been considered in the study.

  • 16.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Aktivitet: IEEE International symposium on Electromagnetic Compatibility2011Annet (Annet (populærvitenskap, debatt, mm))
  • 17.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Aktivitet: International Conference on Harmonics and Quality of Power2010Annet (Annet (populærvitenskap, debatt, mm))
  • 18.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Assessment of recurrent oscillation parameters2018Inngår i: Proceedings of International Conference on Harmonics and Quality of Power, ICHQP, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recurrent damped oscillation can occur more or less in the LV network due to different load connected. The recurrent oscillation has lower amplitude compared to other single damped oscillations events caused by e.g. lightning or switching actions. There is however a need to measure and quantify the recurrent oscillations to increase the understanding and possible consequences of these. This paper describes the phenomena and addresses different analyzing methods where ESPRIT seems to be the most promising analyzing method. In the end, the paper presents some result from a long term measurement at one site with recurrent oscillations and makes some comparisons of different analyzing methods.

  • 19.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    High frequency distortion in power grids due to electronic equipment2006Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Power quality is a subject that has received a lot of attention during the last 10 to 20 years, both in industry and in academia. Power quality concerns interaction between the power grid and its customers and between the power grid and equipment connected to it, reflected in voltages and currents. Research and other developments in this area have to a great extent concentrated on relatively slow and low-frequency phenomena, with the main emphasis being on voltage dips (reductions in voltage magnitude with duration between about 50 ms and several seconds) and low-frequency harmonics (waveform distortion by frequency components up to about 2 kHz). These phenomena are reasonably well understood. For higher-frequency phenomena there is no such general understanding. There are a number of reasons for looking closer into this frequency range, including increased distortion by energy-efficient equipment, interference with equipment such as that used for communications, reduced service life of equipment, the availability of measurement and analysis tools, and pure scientific curiosity. This licentiate thesis addresses voltage and current distortion in low- voltage networks in the frequency range between 2 kHz and 1 MHz. The report starts with a general overview of power quality and power-quality disturbances. This part is mainly a review of existing knowledge. The report continues with a philosophical discussion of measurement and analysis of power-quality disturbances. The objectiveness of the analysis methods is especially addressed. The importance of understanding the limitations posed by measurement standards and commonly used analysis methods is emphasized. The choice of measurement and analysis tool has the potential to influence the conclusions drawn from a study. Different analysis and presentation tools are discussed for disturbances in the frequency band of interest. Where possible, a range of methods should be used. Next to the commonly used time- and frequency-domain presentations, the spectrogram or time-frequency-domain is introduced as a useful tool. The measurement technology used for obtaining sampled voltage and current waveforms is discussed. Measurements have been performed on the current drawn by individual devices and by groups of devices. These measurements have been performed mainly in a controlled laboratory environment. Voltage measurements have mainly been performed at a number of locations in the field. Both current and voltage measurements are described in detail in this report, together with the measurement results. The main contribution of this licentiate report is in the systematic analysis of disturbances in the frequency range between 2 kHz and 1 MHz. The spectrogram has proven a suitable tool for analyzing and visualizing these disturbances. Further knowledge is obtained on the disturbances arising from fluorescent lamps with high-frequency ballasts. Contrary to conventional knowledge, the main concern is in the so-called zero-crossing distortion. The level of this distortion component demonstrates a linear increase with the number of devices.

  • 20.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    On high-frequency distortion in low-voltage power systems2011Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Power quality is a subject that has received a lot of attention during the last 10 to 20 years, both in industry and in academia. Power quality concerns interaction between the power grid and its customers and between the power grid and equipment connected to it, reflected in voltages and currents. Research and other developments in this area have to a great extent concentrated on relatively slow and low-frequency phenomena, with the main emphasis being on voltage dips (reductions in voltage magnitude with duration between about 50 ms and several seconds) and low-frequency harmonics (waveform distortion by frequency components up to about 2 kHz). These phenomena are reasonably well understood and several standards cover the area. For higher-frequency phenomena, above 2 kHz, there is no such general understanding, nor is there anything close to a complete set of standards covering this area. Modern energy efficient equipment connected to the grid, like fluorescent lamps but also solar panels, often uses switching technology, with switching frequencies that can range from a couple of kHz up to several hundreds of kHz. The grid is also used for communication of e.g. meter readings, system controls etc. This so-called power-line communication is using the same frequency range. The main frequency range of interest for this thesis has been the range from 2 to 150 kHz. There are two completely different measurement methods covering this frequency range: time-domain based and frequency-domain based. Time domain based measurements are used throughout the thesis. This gives an opportunity to choose between different analysing tools where among others the joint time-frequency domain has shown to be a useful tool for describing waveform distortion in our frequency range of interest. The majority of the measurements presented in this thesis have been directed towards fluorescent light powered by high frequency ballasts. This type of load has been, due to stringent harmonic limits, one of the first to use a more advanced switching technology called active power factor correction. This technique is also getting more frequently used in other small-power equipment, like computers. Installations of lights in stores etc. normally contain a large number of ballast connected together and the interaction is of importance, for example for setting emission and immunity standards. The measurements on ballasts presented in this work have shown that distortion in the frequency rage 2-150 kHz comes in three types: narrowband distortion; wideband distortion; and recurrent oscillations. The recurrent oscillations are a new type of powerquality disturbance that had not been recognized as such before. The measurements further have shown that the three types of distortion spread in a completely different way from the individual devices to the grid. This knowledge is essential for the setting of emission requirements on energy-efficient equipment.

  • 21.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Emission (2 to 150 kHz) from a light installation2011Inngår i: Proceedings of CIRED 21st International Conference on Electricity Distribution, 2011, artikkel-id 0250Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents results from measurements of the emission from an installation containing of about 50 fluorescent lamps with high-frequency ballast. It is shown that the emission from one individual lamp in the installation is completely different from the emission by the installation as a whole. Emission in the frequency range of a few kHz adds in the current from the total installation, whereas emission around 50 kHz does not show up in the total current.

  • 22.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Emission and immunity of equipment in the frequency range 2 to 150 kHz2009Inngår i: 2009 IEEE Bucharest PowerTech Proceedings / [ed] Lucian Toma ; Bogdan Otomega, Piscataway, N.J.: IEEE Communications Society, 2009, s. 2325-2329Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper gives an overview of emission and immunity standards in the frequency range from 2 to 150 kHz. Based on existing standardization a complete set of limits is proposed by the authors. A distinction is thereby made between narrowband emission, broadband emission and recurrent oscillations. The measuring technique is vital to the results. In this frequency range, there are two different sets of standards covering measurement equipment. Due to fact of development of time-domain based instrument we propose to only use this type of instruments for the whole frequency range.

  • 23.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Measurement result from 1 to 48 fluorescent lamps in the frequency range 2 to 150 kHz2010Inngår i: 14th International Conference on Harmonics and Quality of Power (ICHQP), Piscataway, NJ: IEEE Communications Society, 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper present measurements performed in the lab where experimental setup of 48 fluorescent lamps powered by high-frequency ballasts. The frequency range of interest is above the traditional harmonic range from 2 kHz up to 150 kHz. In this frequency range the measurements distinguish between two distortions found; recurrent oscillations and remains from the switching at the active power factor correction circuit.

  • 24.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Mitigation of main factors that limit the introduction of energy‐efficient lighting systems2012Rapport (Annet vitenskapelig)
    Abstract [sv]

    Detta är slutrapporten från den svenska Energimyndigheten projekt (P31550‐1) "Minskat livslängd av energieffektiv belysning på grund av höga nivåer av elektromagnetiska störningar" som utförs av kraftteknik gruppen vid Luleå Tekniska Universitet. I detta projekt har elektromagnetiska störningar studerats i anläggningar med ett stort antal lysrör med högfrekventa förkopplingsdon (HF‐don). Sådana belysningsanläggningar återfinns i butiker och köpcentra, stora kontor och lagerutrymmen.Projektet har resulterat i ökad kunskap om vågformsdistorsion i frekvensområdet 2 till 150 kHz och spridningen av dessa komponenter inom en belysningsanläggning. Följandekonkreta resultat kan nämnas:Övertoner (under 2 kHz) från en belysningsinstallation är låg jämfört med liknande typer av elektroniska lasterEmission inom frekvensområdet mellan 2 till 150 kHz kan hänföras till rester från om ”switchingen” i HF‐donen och återkommande oscillationer som sker näragrundtonens nollgenomgång Typen av emission från belysningsinstallationer i frekvensområdet 2 till 150 kHz kan delas in i följande:o Smalbandiga komponentero Bredbandiga komponentero Återkommande oscillationerNär belysningen installeras i stora grupper som t.ex. i varuhus så sprids de olikaemissionerna på olika sätt. Resterna från switchingen går framförallt mellanarmaturerna medan de återkommande oscillationerna adderas i amplitud och sprider sig uppåt i nätet mot transformatorn.Anledningen till att resterna från switchingen till största del stannar ibelysningsanläggningen beror på att varje EMC‐filter på AC sidan erbjuder en lågimpedans för dessa komponenter.Rapporten diskuterar också idéer om lämpliga lösningar för att minimera olikaemissioner och om hur man designar belysningsanläggningar och EMC‐filter drivdon.De återkommande oscillationerna kan uppfattas som ett potentiellt problem i stora anläggningar. Det finns även inga tecken ännu att återkommande oscillationer är antingen ett hot eller inte, för den förväntade livslängden hos drivdonen. Här behövs dock ytterligare forskning.

  • 25.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Some consequences for the power grid of high densities of electronic equipment2005Inngår i: First International Conference on Lifestyle, Health and Technology: June 1-3, 2005 at Luleå University of Technology, Porsön, Luleå, Sweden, Luleå: Luleå tekniska universitet, 2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper will highlight some problems that can arrise when many different power supplies are densley connected to the electric mains. Measurements have been made on sites where numerous electronic devices are connected. The results of these measurements are presented and some of the consequences are discussed.

  • 26.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Lundmark, Martin
    Measurement and analysis of high-frequency conducted disturbances2007Inngår i: Conference proceedings: 19th International Conference and Exhibition on Electricity Distribution, Vienna, 21 - 24 May 2007, Liege: AIM , 2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The frequency range above the "traditional" harmonic range up to about 2 to 3 kHz has been under investigation for a while but less attention has been paid to the frequency range slightly above. This paper presents measurements both in laboratory environment and in the field on different types of equipment and general long- term measurement on site in the low voltage network. The general aim of this paper is to increase the knowledge about voltage and current distortion in the frequency range above 2 kHz.

  • 27.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Lundmark, Martin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Measurements of high-frequency (2-150 kHz) distortion in low-voltage networks2010Inngår i: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 25, nr 3, s. 1749-1757Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents different methods to describe voltage and current distortion in the frequency range 2 to 150kHz. The time-frequency domain was shown to give additional information next to the time- and frequency-domain representations. Measurements of different devices and at different locations showed remnants of the switching frequency of the power electronics as well as lower frequency oscillations around the current zero crossing to be present in voltage and current. The voltage distortion is shown to vary a lot during the day and between locations.

  • 28.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Gil-de-Castro, Aurora
    University of Cordoba.
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Field and laboratory measurements of interference with light equipment due to waveform distortion originating from a large rectifier2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper will present a case study where light in anoffice building is disturbed and do not function properly.From measurements it is shown that a UPS system iscausing distortions. One lamp from the office wasbrought to laboratory where the distortions was repeatedand subjected to the lamp. When doing so the lampshowed the same immunity problem.

  • 29.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Bollen, Math
    Distortion of fluorescent lamps in the frequency range 2-150 kHz2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents measurements of voltages and currents taken by fluorescent lamps with high-frequency ballast. The results are discussed in time domain, in frequency domain and in time-frequency domain. A number of different high-frequency components are present: recurrent transients, narrow-band time-invariant signals, and time-dependent signals. The increase in distortion with increasing number of lamps is studied as well. The distortion increases about linear with the number of lamps in the frequency range 2-9 kHz but shows only a minor increase or no increase at all in the frequency range 9-150 kHz.

  • 30.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Bollen, Math
    Measurement of current taken by fluorescent lights in the frequency range 2-150 kHz2006Inngår i: IEEE Power Engineering Society general meeting, 2006: 18 - 22 June 2006, Montreal, QC, Canada, Piscataway, NJ: IEEE Communications Society, 2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper discusses measurements taken on fluorescent lights in the frequency range between 2 and 150 kHz. The presentation of the measurement results form an important part of the paper. The measurement results are presented in time-domain, in the frequency domain and in the time-frequency domain (by means of a "spectrogram"). The latter allows the study of sub-cycle changes in the current spectrum. The current taken by one lamp is compared with the current taken by two, three and four lamps. The relative high-frequency distortion reduced for frequencies above 15 kHz.

  • 31.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Bollen, Math
    Wahlberg, Mats
    Rönnberg, Sarah
    Evolution of the harmonic distortion from state-of-the-art computers: 2002 to 20082009Inngår i: CIRED 20th International Conference on Electricity Distribution: 8 -11 June 2009, Prague Congress Centre, Prague, Red Hook, NY: Curran Associates, Inc., 2009, s. 164-167Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper shows trends in harmonic emission by large groups of modern computers over a 7-year period. The measurements were obtained at computer tournaments where almost exclusively the newest types of computers are used. The measurements clearly show that the harmonic distortion is decreasing significantly while the power consumption per computer does not change significantly.

  • 32.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Reduced life-time of lamps: Temperature rise and bad power quality2014Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To save energy, many new buildings have modern energy saving lighting installed. In large department or grocery stores the use of fluorescent lamps powered by high frequency electronic ballast is common. There are however consistent reports of large numbers of failures of the electronic ballast of these lamps. The failures of the electronic ballast are due to high temperature or bad power quality. But neither of these reasons has been confirmed as the cause. This paper discusses in general the lifetime of electronic ballast. The paper also presents detailed analysis of results from measurement performed in a grocery store where high instances of failure have been observed. Both temperature and power quality in the harmonic range and 2 to 150 kHz have been included in the measurements

  • 33.
    Larsson, Anders
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wahlberg, Mats
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Lundmark, Martin
    Waveform distortion at computer festivals: 2002 to 20082008Inngår i: 2008 13th International Conference on Harmonics and Quality of Power: [ICHQP 2008] ; Wollongong, Australia, 28 September - 1 October 2008, Piscataway, NJ: IEEE Communications Society, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper shows measurements of the harmonic emission by large groups of state-of-the-art computers measured at five different occasions from 2002 to 2008. The emission was measured during LAN-festivals where the participants use mainly the newest models of computer. This allows insight in the change in emission of computers during the last 6 years. The results from these measurements show that the distortion level generated by computers is decreasing while the power consumption does not show any significant change.

  • 34.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Projekt: Minskad livslängd av energieffektiv belysning på grund av höga nivåer av elektromagnetiska störningar2012Annet (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Ett potentiellt hinder mot införandet av energisnål belysningsteknik är en förtätad användning av kraftelektronikbaserade ljuskällor eftersom dessa kan ge en alltför hög generering av ledningsbundna elektromagnetiska störningar. Målet med projektet är att kartlägga hur den elektromagnetiska störnivån förändras vid olika typer av installationsteknik, ökande antal störkällor mm. Delmål är att utveckla befintlig mätteknik och analysmetoder och studera olika elektronikkonstruktioner.

  • 35.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Hagelberg, Jan-Olof
    Larsson, Anders
    Byström, Mikael
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Åke
    Chalmers University of Technology.
    The use of protective earth as a distributor of fields and radiation2000Inngår i: Biological effects of EMFs: [Millennium International Workshop on Biological Effects of Electromagnetic Fields] ; Heraklio, Crete, Greece, 17 - 20 October 2000 ; proceedings / [ed] P. Kostarakis, Heraklio: Workshop on Biological Effects of Electromagnetic Fields , 2000Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Apart from being a safety arrangement, the protective earth, PE, is also defined as an equipotential plane which serves as a reference voltage for a circuit. Interest in the PE for EMC reasons is focused on an equipotential point. Still, most PE installation on site is carried out as a safety arrangement. In order to fulfill EMC standards regarding low emission, equipment is shielded and the shield is connected to the PE wire.The purpose of this paper is to show that electrical equipment distributes its electrical fields using the PE wire. Measurements have been taken on light fittings.

  • 36.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Bollen, Math
    Harmonics and high-frequency emission by small end-user equipment2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper discusses different treatments of harmonics in three phase systems, especially passive and active power factor correction (PFC). The change from harmonics below 2 kHz to above 2 kHz is described. Measurements have been carried out with two types of computer load together with LCD and florescent light driven by electronic ballast: on a large number of devices during a LAN party and on individual devices in the laboratory. Also some aspects of increasing numbers of equipment are illustrated.

  • 37.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Bollen, Math
    High-frequency components in the neutral and protective earth currents due to electronic equipment2007Inngår i: Conference proceedings: 19th International Conference and Exhibition on Electricity Distribution : Vienna, 21 - 24 May 2007, Liege: AIM , 2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper addresses the issue of neutral and protective earth currents in the frequency range 2 through 150 kHz. Both theoretical analysis and measurements will be presented. It is concluded that a large part of the high frequency distortion in the phase currents closes via the neutral wire and impacts the terminal voltage for equipment in the other phases. The introduction of HF-harmonics is even more detrimental to the intention with three-phase systems to minimize the currents outside the phase conductors.

  • 38.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Projekt: Livslängd av energieffektiv belysning vid höga nivåer av elektromagnetiska störningar2012Annet (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Byte till energisnål belysning är enligt flera forskningsstudier det mest kostnadseffektiva sättet att minska koldioxidutsläpp. Livslängden för belysning måste dock vara tillräckligt lång för att den minskade energianvändningen ska ha en ekonomisk fördel. Det är denna livslängd som ifrågasätts. Den begränsade hållfasthet ”immunitet” som belysning har mot störningar i spänningen kan vara en orsak till den minskade livslängden. Det behövs ny kunskap om detta förhållande för att kunna utveckla testmetoder, sätta gränsvärden på immunitet och kunna öka livslängden på belysningsinstallationer.

  • 39.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Bollen, Math
    Required changes in emission standards for high-frequency noise in power systems2006Inngår i: International Journal of Energy Technology and Policy, ISSN 1472-8923, Vol. 4, nr 1-2, s. 19-36Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper discusses some recent developments that make the existing standards on the emission of high-frequency noise in power systems need to be reconsidered. It is shown that it is possible for an equipment to remain below the emission limits while at the same time the disturbance level increases beyond what was intended by the standard document. Further, the change from analog to digital communication and the use of communication via the power system, make that the permitted disturbance levels need to be reconsidered. This paper also contains an example of measured high-frequency noise and proposes a framework for re-coordination of emission and immunity levels.

  • 40.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Bollen, Math
    Unintended consequences of limiting high-frequency emission by small end-user equipment2006Inngår i: IEEE Power Engineering Society General Meeting: 18 - 22 June 2006, [Montreal, QC, Canada, Piscataway, NJ: IEEE Communications Society, 2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper discusses some consequences of developments in technologies that may impact the risk of electromagnetic interference and equipment damage despite the equipment complying with the tests according to the product standards. Examples of such technologies are: the change from analogue to digital communication, the fast increase in numbers of power converters having smart switching technology and the use of communication via the power system. The paper discusses upcoming sources of emission, uncertainties in emission level, and changing circumstances. It is shown that it is possible for equipment to remain below the emission limits while at the same time the disturbance level increases beyond what was intended by the standard document. The paper also proposes a framework for addressing the problems due to massive penetration of equipment injecting high-frequency harmonics.

  • 41.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Hagelberg, Jan-Olof
    Förstudie gällande förekomst av elektriska fält i kontorsmiljöer inom frekvensområdet 10kHz - 30MHz2002Rapport (Annet vitenskapelig)
    Abstract [sv]

    Projektet EMC on SITE i Skellefteå har av SIF erhållit ett uppdrag att undersöka nuläget gällande förekomst av elektriska fält i kontorsmiljöer inom frekvensområdet 10 kHz - 30 MHz. Mätningarna utfördes under senvåren - sommaren 2001. En mycket intressant iakttagelse är, i de fall belysningen består av lysrör med högfrekvensdrift (HF-drift), att det elektriska fältets styrka till största delen bestäms av belysningen, och inte av bildskärmar. Vid lysrörsanläggningar med konventionell drift (med reaktor som förkopplingsdon) var nivåerna typiskt lägre än nivån från de bildskärmar som förekom på mätplatsen. De typiska nivåerna från lysrör med HF-drift var tio ggr starkare än de från de katodstrålerörbaserade bildskärmar som fanns på mätplatserna. En annan mycket intressant iakttagelse är att bakgrundsfältet (det elektriska fältet som kvarstår när olika källor som belysning och bildskärmar slagits av), har en sådan karaktär att skyddsjordsystemet kan ha distribuerat signaler från jordade apparater i andra rum i byggnaden, till det rum där mätning skedde. I projektet har vi tidigare visat att på det sätt som skyddsjordning är utfört i våra byggnader, så kan elektriska fält av nätfrekvens (50Hz) i de flesta fall hanteras via anslutning till skyddsjord. Konsekvensen av att använda skyddsledaren för att eliminera elektriska fält för högre frekvenser, kan dock i många fall vara att den totala nivån av det elektriska fältet i byggnaden ökar. Höga nivåer av elektriska fält i luft eller höga nivåer av högfrekvent brus i våra ledningssystem (kraftnät, datanät mm.), kan allvarligt störa tekniska funktioner eller t.o.m. förstöra dem. Om vi med trovärdighet skall fortsätta med att testa och godkänna bildskärmar gällande elektriska fält, så måste de i detta fall förhållandevis höga nivåerna från lysrör med HF-drift uppmärksammas och hanteras på ett bättre sätt. Inte minst därför att ljuskällor förekommer i alla typer av lokaler, i ett betydligt större antal än bildskärmar totalt sett, samt att ökningstakten för HF-drift är mycket stor.

  • 42.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Larsson, Åke
    Chalmers University of Technology.
    Holmlund, Patrik
    Increased levels of electrical fields in buildings2002Inngår i: Biological effects of EMFs : proceedings, Rhodes, Greece, 7 - 11 October 2002: [International Workshop on Biological Effects of Electromagnetic Fields] / [ed] P. Kostarakis, Rhodes: University of Ioannina , 2002Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In order to save energy and improve the performance, various electrical apparatus are equipped with power electronics. Normally power electronic equipment produce harmonics and high frequency noise. To handle noise emission, power electronic equipment uses EMC filters and are tested according to EMC standards. But the question is whether these tests are enough to avoid noise emissions in buildings? It has been shown, that electrical equipment distributes electrical fields inside a building using the PE wire. In order to avoid or limit electrical field it is necessary to find the sources and stop the distribution. The levels of electrical fields in the frequency range between 10 kHz and 30 MHz in office buildings and homes are rather unknown. One reason is lack of civil standards, another is lack of and difficulties in measurements.In this paper results from measurements of electrical fields in the frequency range between 10 kHz and 30 MHz at different locations is shown. An interesting result from these measurements is that the level of the electrical fields from a HF-fittings are approximately 10 times the level from video display units (VDU). This paper also shows a method to analyze sources of electrical fields.

  • 43.
    Lundmark, Martin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Wahlberg, Mats
    Larsson, Anders
    Bollen, Math
    EMC filter common mode resonance2009Inngår i: 2009 IEEE Bucharest PowerTech: Bucharest, Romania, 28 June - 2 July 2009 / [ed] Lucian Toma, Piscataway, NJ: IEEE Communications Society, 2009, s. 2312-2317Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper discusses the possibility that high common mode voltages occur in low-voltage distribution due to oscillations between parallel connected EMC-filters. It is shown that such oscillations may occur in the frequency range between 2 kHz to 150 kHz. Simulations and measurements have been carried out with different types of parallel connected power inlet filter, a common EMC Filter, and the circumstances giving oscillations have been highlighted.

  • 44.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Emission from small scale PV-installations on the low voltage grid2014Inngår i: The Renewable Energies and Power Quality Journal (RE&PQJ), ISSN 2172-038X, E-ISSN 2172-038X, nr 12, artikkel-id 427Artikkel i tidsskrift (Fagfellevurdert)
  • 45.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Grid impact from PV-installations in northern Scandinavia2013Inngår i: 22nd International Conference and Exhibition on Electricity Distribution (CIRED 2013): Stockholm, Sweden, 10 - 13 June 2013, Red Hook, NY: Curran Associates, Inc., 2013, artikkel-id 1036Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The use of solar panels is becoming more popular in Sweden. Parts of Scandinavia have many sun hours and the cold temperatures are advantageous as they lead to higher efficiencies and longer lifetimes of the solar cells. Except during the darkest time of the year (Nov-Feb) PV is a suitable complement for power production also in the northern parts of Scandinavia, especially when using a proper tracking system In this paper power quality issues concerning the connection of photovoltaic systems will be discussed. Emission up to 25 kHz will be presented as well as voltage variations caused by the production. Measurements from three phase connected plants (20 kW) and from smaller (up to 2.5 kW) single phase connected plants are shown. The harmonic emission from PV-plants is reasonable low and somewhat constant with regards to the production. Some residue from the switching of the inverter can be found typical at a few kHz.

  • 46.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    An overview of the origin and propagation of Supraharmonics (2-150 kHz)2014Konferansepaper (Fagfellevurdert)
  • 47.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Emission from different types of energy efficient lamps at frequencies up to 150 kHz2012Konferansepaper (Fagfellevurdert)
  • 48.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Schanen, Jean-Luc
    Grenoble Electrical Engineering Lab.
    A simple model for interaction between equipment at a frequency of some tens of kHz2011Inngår i: Proceedings of CIRED 21st International Conference on Electricity Distribution, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a simple model to explain the spread of high-frequency current between different devices and into the grid. The model is also used to show the aggregation between devices. The model is used to predict the amplitude modulation of the voltage and current ripple due to the small frequency differences between devices. The results from the model confirm earlier measurement results.

  • 49.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Andersson, Marcus
    Luleå tekniska universitet.
    Larsson, Anders
    Bollen, Math
    Wahlberg, Mats
    Skellefteå Kraft AB.
    Attenuation and noise level: potential problems with communication via the power grid2007Inngår i: Conference proceedings: 19th International Conference and Exhibition on Electricity Distribution : Vienna, 21 - 24 May 2007, Liege: AIM , 2007, artikkel-id 0186Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper will give examples of the potential problems associated with remote-meter reading via the power grid and describe some of the technologies available. Examples will be given of practical cases in which the communication channel does not function in the intended way. Three potential problems with communication via the power grid are identified in the paper:The noise level is too high for the information to reach the receiverThe attenuation at the frequencies used for communication is too high. Several cases have been identified where this made communication impossible. Certain types of end-user equipment cause a large attenuation of the communication signal, so that a too small amount of the signal reaches the receiverInterference with other equipment. A flicker problem was found due to a modulated 100-Hz signal used for communication

  • 50.
    Rönnberg, Sarah
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wahlberg, Mats
    Bollen, Math
    Larsson, Anders
    Lundmark, Martin
    Measurement of interaction between equipment in the frequency range 9 to 95 kHz2009Inngår i: CIRED 20th International Conference on Electricity Distribution: (CIRED 2009) ; Prague, Czech Republic, 8 - 11 June 2009, Red Hook, NY: Curran Associates, Inc., 2009, s. 231-234Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A number of measurements have been performed on a full-scale electric model of a house to study equipment emission and impedances in the frequency range 9-95 kHz. Most equipment forms a much lower impedance path that the grid. The result is that conducted disturbances in this frequency range mainly flow between individual devices instead of between devices and the grid. It is also shown that the input impedance of equipment can be highly time dependent at a time scale below one cycle of the power-system frequency.

12 1 - 50 of 64
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