| 1. |
- Andersson, Marcus, et al.
(författare)
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Interfering signals and attenuation : potential problems with communication via the power grid
- 2006
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Ingår i: Proceedings of Nordic Distribution and Asset Management Conference.
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 2. |
- Bollen, Math, et al.
(författare)
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Harmonic emission from installations with energy-efficient lighting
- 2011
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Ingår i: Proceeding of the International Conference on Electrical Power Quality and Utilisation, EPQU. - Piscataway, NJ : IEEE Communications Society. - 9781467303798 ; , s. 797-802
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Konferensbidrag (refereegranskat)abstract
- 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
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| 3. |
- Bollen, Math, et al.
(författare)
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Limits for voltage distortion in the frequency range 2 to 9 kHz
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:3, s. 1481-1487
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
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| 5. |
- Bollen, Math, et al.
(författare)
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Standards for supraharmonics (2 to 150 kHz)
- 2014
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Ingår i: IEEE Electromagnetic Compatibility Magazine. - 2162-2264. ; 3:1, s. 114-119
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Tidskriftsartikel (refereegranskat)abstract
- 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
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| 6. |
- Larsson, Anders, et al.
(författare)
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Distortion of fluorescent lamps in the frequency range 2-150 kHz
- 2006
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 7. |
- Larsson, Anders, et al.
(författare)
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Evolution of the harmonic distortion from state-of-the-art computers : 2002 to 2008
- 2009
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Ingår i: CIRED 20th International Conference on Electricity Distribution. - Red Hook, NY : Curran Associates, Inc.. - 9781615675227 ; , s. 164-167
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 8. |
- Larsson, Anders, et al.
(författare)
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Measurement and analysis of high-frequency conducted disturbances
- 2007
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Ingår i: Conference proceedings. - Liege : AIM.
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 9. |
- Larsson, Anders, et al.
(författare)
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Measurement of current taken by fluorescent lights in the frequency range 2-150 kHz
- 2006
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Ingår i: IEEE Power Engineering Society general meeting, 2006. - Piscataway, NJ : IEEE Communications Society. - 1424404932
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 10. |
- Larsson, Anders, et al.
(författare)
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Measurements of high-frequency (2-150 kHz) distortion in low-voltage networks
- 2010
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 25:3, s. 1749-1757
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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