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  • 151.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Hosting Capacity of the Power Grid for Renewable Electricity Production and New Large Consumption Equipment2017Ingår i: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 10, nr 9, artikel-id 1325Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    After a brief historical introduction to the hosting-capacity approach, the hosting capacity is presented in this paper as a tool for distribution-system planning under uncertainty. This tool is illustrated by evaluating the readiness of two low-voltage networks for increasing amounts of customers with PV panels or with EV chargers. Both undervoltage and overvoltage are considered in the studies presented here. Probability distribution functions are calculated for the worst-case overvoltage and undervoltage as a function of the number of customers with PV or EV chargers. These distributions are used to obtain 90th percentile values that act as a performance index. This index is compared with an overvoltage or undervoltage limit to get the hosting capacity. General aspects of the hosting-capacity calculations (performance indices, limits, and calculation methods) are discussed for a number of other phenomena: overcurrent; fast voltage magnitude variations; voltage unbalance; harmonics and supraharmonics. The need for gathering data and further development of models for existing demand is emphasised in the discussion and conclusions

  • 152.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Modelling and simulation issues resulting from extended measurements2015Ingår i: 2015 IEEE Power & Energy Society General Meeting: 26-30 July 2015, Denver CO, Piscataway, NJ: IEEE Communications Society, 2015, artikel-id 7285961Konferensbidrag (Refereegranskat)
    Abstract [en]

    Presents a collection slides covering the following topics: supraharmonics propagation; measurement modeling; grid supply terminals; device terminals; secondary emission; primary emission; voltage measurement and capacitor

  • 153.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Nya lågspänningslaster och störningar i frekvensområdet 2 till 150 kHz: resultat från forskningsprojektet vid Luleå tekniska universitet, samt en kartläggning av behovet på ytterligare forskning2011Rapport (Övrigt vetenskapligt)
  • 154.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Primary and Secondary Harmonics Emission: Harmonic interaction - A set of definitions2016Ingår i: 2016 17th International Conference on Harmonics and Quality of Power, Piscataway, NJ: IEEE Computer Society, 2016, s. 703-708, artikel-id 7783333Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes a set of definitions to simplify the discussion about the different contributions to the harmonic currents at the terminals of a device or an installation. Definitions are given, and explained, for 'primary harmonic emission', 'secondary harmonic emission', and 'harmonic interaction'

  • 155.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Typical harmonic levels and spectra with low-voltage customers2019Konferensbidrag (Refereegranskat)
  • 156.
    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 lighting2011Ingår i: Proceeding of the International Conference on Electrical Power Quality and Utilisation, EPQU, Piscataway, NJ: IEEE Communications Society, 2011, s. 797-802Konferensbidrag (Refereegranskat)
    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

  • 157.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Laboratory and field measurements of the power factor and the harmonic emission from energy-efficient lamps2011Konferensbidrag (Refereegranskat)
  • 158.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zavoda, Francisc
    IREQ, IREQ/HQ, Hydro-Québec Research’s Institute.
    CIGRE/CIRED C4.24 – power quality in the future grid – first introduction2014Konferensbidrag (Refereegranskat)
  • 159.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zavoda, Francisc
    IREQ (HQ), Varennes.
    Langella, Roberto
    Second University of Naples.
    Djokic, Sasa
    University of Edinburgh.
    Cuifo, Philip
    University of Wollongong.
    Meyer, Jan Christian
    Technische Universitaet Dresden.
    Cuk, Vladimir
    Eindhoven University of Technology.
    Consequences of Smart Grids for Power Quality Overview of the Results from CIGRE Joint Working Group C4.24/CIRED2018Ingår i: 2017 IEEE PES Innovative Smart Grid Technologies Conference Europe, ISGT-Europe 2017: proceedings, New York: Institute of Electrical and Electronics Engineers (IEEE), 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper gives an overview of the expected unintended (negative) consequences for power quality of several on-going developments in the power system. Four developments directly related to smart-grid technology are covered: microgrids; advanced voltage control; feeder reconfiguration; and demand-side management. Four developments indirectly related are also covered: new sources of electricity production; increased used of active power-electronic converters; shift from overhead lines to cables; and new types of lighting. The paper summarizes the discussions in an international working group and presents the main findings are recommendations.

  • 160.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zavoda, Francisc
    IREQ.
    Zhong, Jin
    University of Hongkong.
    Djokic, Sasa
    University of Edinburgh.
    Das, Ratan
    ABB.
    Halpin, Mark
    Auburn University Montgomery, Alabama.
    CIGRE/CIRED working group C4.24 – power quality and EMC issues associated with future electricity networks – status report2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper gives a status report of joint working group C4.24. Next to an overview of the different activities started, more details are given of the work done on voltage dips, new sources of emission, feeder reconfiguration, demand side management and power quality and economics.

  • 161.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sabin, D.D
    International coordination for voltage sag indices2006Ingår i: 2006 IEEE/PES Transmission & Distribution Conference and Exposition: Latin America : Caracas, Venezuela, 15-18 August 2006, Piscataway, NJ: IEEE Communications Society, 2006Konferensbidrag (Refereegranskat)
  • 162.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Samuelsson, O.
    Lund University.
    Controlled island operation of part of the 50-kV grid in Southern Sweden2009Ingår i: 2009 IEEE Bucharest PowerTech Proceedings: Bucharest, Romania June 28 - July 2, 2009 / [ed] Lucian Toma, Piscataway, NJ :: IEEE Communications Society, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper is based on measurements obtained during a test of controlled islanding of part of the 50-kV grid in Southern Sweden. The purpose of the test was to verify operation of generator controls during islanding. The variations in voltage magnitude and frequency are shown as well as flicker severity and very-short variations. A number of performance indices have been calculated and compared with limits. Voltage magnitude and frequency have been studied in some detail around the disconnection and reconnection instants. The frequency varies much more during the island operation than during grid-connected operation. Voltage magnitude variations and flicker remain within their normal range. However the variations in the time range between 3 seconds and 10 minute appear to be higher than normal.

  • 163.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Schwaegerl, C
    Schmitt, S
    Distributed energy resources and waveform distortion2007Ingår i: Conference proceedings: 19th International Conference and Exhibition on Electricity Distribution : Vienna, 21 - 24 May 2007, Liege: AIM , 2007Konferensbidrag (Refereegranskat)
  • 164.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sollerkvist, F
    The hosting capacity of distribution networks against high-frequency harmonics emitted by distributed energy resources2006Ingår i: 12th International Conference on Harmonics and Quality of Power, 2006Konferensbidrag (Refereegranskat)
  • 165.
    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 distortion2006Ingår i: Proceedings of Nordic Distribution and Asset Management Conference: NORDAC 2006, 2006Konferensbidrag (Refereegranskat)
  • 166.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Speychal, M
    STRI AB.
    Lindén, K
    STRI AB.
    Estimation of dip frequency from fault statistics: including three-phase characteristics2006Ingår i: International Conference on Probabilistic Methods Applied to Power Systems, 2006: PMAPS 2006 ; 11 - 15 June 2006, [Stockhom, Sweden], Piscataway, NJ: IEEE Communications Society, 2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper describes methods for estimating the voltage dip frequency, due to faults, experienced by customers. The input to the calculation consists of fault statistics from network operators. The calculations are based on the method of fault positions, extended with a three-phase classification of voltage dips

  • 167.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Stephens, Mark
    EPRI.
    Stockman, K
    Djokic, S
    McEachern, A
    Gordon, J Romero
    Voltage dip immunity of equipment in installations2008Ingår i: Electrical Power Quality and Utilization, ISSN 1234-6799, Vol. 3, nr 2Artikel i tidskrift (Övrigt vetenskapligt)
  • 168.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Stephens, Mark
    EPRI.
    Stockman, K
    Djokic, S
    McEachern, A
    Gordon, J Romero
    Voltage dip immunity of equipment in installations: scope and status of the work, January 20082008Ingår i: CIGRE Sessions: CD ROM 2008 Session Papers, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents the status of the work, by April 2008, in C4.110, a joint working group by CIGRE, CIRED and UIE. Contributions of the working group are: a summary of voltage dip characteristics; a methodology to assess the performance of a complete installation and; recommendations for testing and immunity of equipment.

  • 169.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Stephens, Mark
    EPRI.
    Stockman, K
    Djokic, S
    McEachern, A
    Gordon, J Romero
    Voltage dip immunity of equipment in installations: scope and status of work2007Ingår i: CIGRE Symposium 2007: Transient phenomena in large electric power systems, Zagreb, Croatia 18-21 April 2007, 2007Konferensbidrag (Refereegranskat)
  • 170.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Stephens, Mark
    Stockman, Kurt
    Djokic, Sasa
    McEachern, Alex
    Gordon, Jose Romero
    Imunidadede equipamentose instalaçõesa afundamentosde tensão2008Ingår i: Eletricidade Moderna, ISSN 0100-2104, s. 138-146Artikel i tidskrift (Övrigt vetenskapligt)
  • 171.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Stockman, K
    Hogeschool West, Vlaanderen, Kortrijk.
    Neumann, R
    Qualitrol, Belfast.
    Ethier, G
    Hydro-Québec Research’s Institute.
    Gordon, J Romero
    Endesa, Sevilla.
    Reussel, K van
    KU Leuven.
    Djokic, S. Z
    University of Edinburgh.
    Cundeva, S
    University Sts. Cyrill and Methodias, Skopje.
    Voltage dip immunity of equipment and installations: messages to stakeholders2012Ingår i: 15th International Conference on Harmonics and Quality of Power (ICHQP), IEEE Communications Society, 2012, s. 915-919Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents the messages to the stakeholders on voltage-dip immunity as extracted by UIE WG2 from CIGRE TB412 [1]. The paper summarizes the main recommendations from this technical brochure in the form of messages towards regulators, standard-setting-organizations, network operators, industrial customers, equipment manufacturers, and power quality monitor manufacturers, researchers.

  • 172.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Styvaktakis, Emmanouil
    Chalmers University of Technology, Department of Signals and Systems.
    Gu, Irene Yu- Hua
    Chalmers University of Technology, Department of Signals and Systems.
    Categorization and analysis of power system transients2005Ingår i: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 20, nr 3, s. 2298-2306Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Power system transients are power-quality disturbances that can be harmful to electronic equipment. This paper contributes and provides some solutions to the following issues: 1) to introduce a new way to identify different categories of power system transients based on their underlying causes; 2) to propose a model and analysis tool for oscillatory transients, where emphasis is on finding phenomena and characteristics associated with the underlying causes of transients. A model-based approach, ESPRIT, is applied to a number of simulated voltage waveforms to extract the parameters of oscillatory transients, and the results may be used for identifying and understanding the causes of transients by correlating the major components in transients with the phenomena that may appear in different types of transients and some a priori knowledge of power system settings

  • 173.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sun, Y.
    STRI AB.
    Ault, G.W.
    Institute for Energy and Environment, University of Strathclyde, Glasgow.
    Reliability of distribution networks with DER including intentional islanding2005Ingår i: International Conference on Future Power Systems, 2005 : [(FPS)]: 16 - 18 Nov. 2005, [Amsterdam, Netherlands], Piscataway, NJ: IEEE Communications Society, 2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents methods for calculating the reliability of distribution systems with distributed energy resources (DER). The impact of intentional islanding of the DER units on the reliability is studied in detail. Different levels of automation are considered, starting from the existing network and continuing with increasing levels of intelligence in the network. The role of the switching devices and of the restoration process is discussed in detail.

  • 174.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Trhulj, Jasmina
    AERS.
    Beyer, Yvonne
    NMA.
    Vailati, Riccardo
    AEEG.
    Styvaktakis, Emmanouil
    RAE.
    Friedl, Werner
    E-Control.
    A European benchmarking of voltage quality regulation2013Ingår i: 22nd International Conference and Exhibition on Electricity Distribution (CIRED 2013): Stockholm, Sweden, 10 - 13 June 2013, Red Hook, NY: Curran Associates, Inc., 2013, artikel-id 350Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Council of European Energy Regulators has been publishing Benchmarking Reports on the Quality of Electricity Supply since 2001. For the 2011 edition of the Benchmarking Report the 29 member countries of CEER were joined by the 9 NRAsfrom the Energy Community and the NRA from Switzerland. This paper contains the main results, findings and recommendations on voltage quality from the 2011 edition.

  • 175.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Verde, Paola
    University of Cassino.
    A framework for regulation of RMS voltage and short-duration under and overvoltages2008Ingår i: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 23, nr 4, s. 2105-2112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper proposes a general approach for voltage-quality regulation. The same framework covers voltage-amplitude variations, dips, and swells. The framework uses the difference between power-quality events and power-quality variations to introduce a "responsibility-sharing curve" distinguishing between normal operational voltage for which equipment should be immune and events that are subject to voltage-quality regulation. It is further proposed to use equipment immunity requirements as a basis for the responsibility-sharing curve.

  • 176.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wallin, Lars
    Svenska Kraftnät.
    Ohnstad, Trond
    Statnett.
    Bertling, Lina
    Svenska Kraftnät.
    On operational risk assessment in transmission systems: weather impact and illustrative example2008Ingår i: Proceedings of the 10th International Conference on Probabilistic Methods Applied to Power Systems: PMAPS 2008, Piscataway, NJ: IEEE Communications Society, 2008, s. 218-223Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper discusses a number of aspects of operational-risk assessment of transmission systems. perational-risk assessment uses techniques developed from reliability analysis to predict the performance of the transmission system during a short period of time (several hours) starting from a well-defined operational state. The influence of weather parameters on the momentary failure rate and the operational risk is discussed in this paper as well. The operational-risk method is illustrated by means of a simple but realistic transmission-system model. The paper also discusses some of the applications for such methods in operation and planning of transmission systems.

  • 177.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wang, Ying
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Voltage sag indices: future directions2015Ingår i: 2015 IEEE Power & Energy Society General Meeting: 26-30 July 2015, Denver CO, Piscataway, NJ: IEEE Communications Society, 2015Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Presents a collection of slides covering the following topics: voltage-dip characteristics; complex dip recording; transient segment; phase-angle jump; and information extraction.

  • 178.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Kai
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Harmonic aspects of wind power integration2013Ingår i: Journal of Modern Power Systems and Clean Energy, ISSN 2196-5625, E-ISSN 2196-5420, Vol. 1, nr 1, s. 14-21Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    This paper discusses a number of ways in which wind power installations can impact the harmonic levels in the power system. Wind turbines are an additional source of harmonic emission, especially when it concerns “non-characteristic harmonics.” Parallel resonances can amplify the emission from individual turbines. A mathematical model is developed to quantify this amplification. Series resonances can result in high currents, driven by the background voltage distortion in the transmission grid, flowing into the wind park. Weakening of the transmission grid will increase lower order harmonics but reduce higher order harmonics.

  • 179.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Kai
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Harmonics – another aspect of the interaction between wind-power installations and the grid2013Ingår i: 22nd International Conference and Exhibition on Electricity Distribution (CIRED 2013): Stockholm, Sweden, 10 - 13 June 2013, Red Hook, NY: Curran Associates, Inc., 2013, artikel-id 408Konferensbidrag (Refereegranskat)
    Abstract [en]

    Wind parks are known as sources of harmonic distortion. The emission at the classical harmonic frequencies (low order non-triplen odd harmonics) is however low. Potential problems with connecting individual turbines and wind parks occur at non-standard frequencies, mainly due to harmonic resonances. Next to the harmonic currents driven by the emission from the turbines, studies should also consider the currents driven by the harmonic background distortion.

  • 180.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Kai
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Interharmonic currents from a Type-IV wind energy conversion system2017Ingår i: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, Vol. 143, s. 357-364Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents, for the first time, the verification of the classic model for the origin of interharmonic emission from a frequency converter, for a Type-IV wind turbine by using long-term measurements. Interharmonic variations in magnitude and in frequency are due to the difference between the generator-side and grid-side frequency of the full-power converter. The model verification consists of three parts: correlation between frequencies; relation between magnitude of interharmonics and active-power production, and relation between magnitudes of different interharmonics. The measurements are in agreement with the model predictions. The paper also introduces a novel graphical correlation method to extract information on interharmonics from long-term measurement series.

  • 181.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Yongtao
    STRI.
    Hassan, Fainan
    STRI.
    Integration of distributed generation in the power system: a power quality approach2008Ingår 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, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper gives an overview of the design and operation issues in distribution and transmission systems due to the integration of distributed generation. The hosting-capacity approach has been developed to obtain a quantitative measure on the amount of generation that can be connected without impairing the performance of the system. The hosting-capacity approach requires a set of well-defined performance indices together with acceptable limits.

  • 182.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yao, Liangzhong
    Areva T and D, Technology Centre, Stafford.
    Rönnberg, Sarah
    Wahlberg, Mats
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Harmonic and interharmonic distortion due to a windpark2010Ingår i: IEEE Power and Energy Society General Meeting, Piscataway, NJ: IEEE Communications Society, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper discusses two aspects of the impact of windparks on the waveform distortion in the power system: emission and resonances. The paper gives a general overview of the emission and shows measurement results from a small but modern windpark connected to a 10-kV feeder and estimates the need for network strength to limit the resulting voltage distortion. The paper also gives a general overview of harmonic resonances associated with windparks and illustrates this by means of two numerical examples. Important conclusions from this paper are than harmonic resonances are more likely to be a concern that the emission from windparks, and that the interharmonic emission and the emission at non-characteristic harmonics are more prominent than with existing installations.

  • 183.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhong, J
    University of Hongkong.
    Lin, Y
    University of Hongkong.
    Performance indices and objectives for microgrids2009Ingår i: CIRED 20th International Conference on Electricity Distribution: (CIRED 2009) ; Prague, Czech Republic, 8 - 11 June 2009, Red Hook, NY: Curran Associates, Inc., 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper gives recommendations to researchers and developers on how to evaluate the performance of microgrids during island operation. A microgrid is a small grid including distributed energy resources and loads that can operate independently in the case of emergency of distribution systems. During island operation, the performance requirements of microgrids could be different than those during interconnected operation. To quantify the performance of microgrids, we propose a number of performance indices for voltage quality and reliability.

  • 184.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhong, J.
    University of Hongkong.
    Samuelsson, O.
    Lund University.
    Björnstedt, J.
    Lund University.
    Performance indicators for microgrids during grid-connected and island operation2009Ingår i: 2009 IEEE Bucharest PowerTech Proceedings / [ed] Mircea Eremia, Piscataway, NJ: IEEE Communications Society, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper discusses methods for quantifying the performance of microgrids during island operation. Such methods are essential for comparing different designs and different control algorithms. Performance indicators and objectives are proposed for voltage-quality variations, for individual dips and interruptions, and for the reliability during island operation.

  • 185.
    Bollen, Math
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhong, Jin
    University of Hongkong.
    Zavoda, Francisc
    Hydro-Québec Research’s Institute.
    Meyer, Jan
    Technische Universität Dresden.
    McEachern, Alex
    Power Standards Labs, San Francisco.
    López, Felipe Córcoles
    Polytechnical University of Catalonia, Barcelona.
    Power quality aspects of smart grids2010Konferensbidrag (Refereegranskat)
  • 186. Boman, C
    et al.
    Nordin, A
    Boström, D
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Pettersson, Esbjörn
    Characterisation of inorganic particulate matter from domestic combustion of pelletized biomass fuels2001Konferensbidrag (Övrigt vetenskapligt)
  • 187.
    Boman, Christoffer
    et al.
    Umeå universitet.
    Israelsson, S.
    Umeå universitet.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, B.
    Glommers Miljöenergi AB, Glommersträsk.
    Combustion properties and environmental performance during small scale combustion of pelletized white hardwood raw material2008Ingår i: Proceedings: World Bioenergy 2008 : [Conference & Exhibition on Biomass for Energy, 27 - 29 May 2008, Jönköping - Sweden] / [ed] Johan Vinterbäck, Stockholm: Swedish Bioenergy Association (SVEBIO) , 2008, Vol. Oral session, s. 241-246Konferensbidrag (Refereegranskat)
  • 188.
    Boman, Christoffer
    et al.
    Umeå universitet.
    Mudway, I.S.
    King's College London.
    Wiinikka, Henrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Pettersson, Esbjörn
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Nyström, R.
    Umeå universitet.
    Grönberg, C.
    Energy Technology Centre, Piteå.
    Öhrman, Olov
    Pagels, J.
    Ergonomics and Aerosol Technology, Lund University.
    Swietlicki, E.
    Nuclear Physics, Lund University.
    Genberg, J.
    Nuclear Physics, Lund University.
    Westerholm, R.
    Analytical Chemistry, Stockholm University.
    Blomberg, A.
    Department of Public Health and Clinical Medicine, Umeå university.
    Sandström, T.
    Department of Public Health and Clinical Medicine, Umeå university.
    In vitro screening of biomass combustion aerosol toxicity: Part 1: Oxidative potential2011Ingår i: Wärme aus Holz – Feinstaubemissionen: Scientific Contributions, 2011Konferensbidrag (Övrigt vetenskapligt)
  • 189.
    Boman, Christoffer
    et al.
    Umeå universitet.
    Nordin, Anders
    Umeå universitet.
    Pettersson, Esbjörn
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Wiinikka, Henrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    State-of-the-art of small-scale biomass combustion with respect to fine particle emissions: country report from Sweden2008Ingår i: Tagungsband: proceedings; Graz (Österreich) 16. - 19. Jänner 2008, Wien: Österreichischer Biomasse-Verband , 2008Konferensbidrag (Övrigt vetenskapligt)
  • 190.
    Boman, Christoffer
    et al.
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Nyström, Robin
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Sandström, Thomas
    Institutet för Folkhälsa och klinisk medicin, Enheten för medicin/Lungmedicin och allergologi, Umeå universitet.
    Blomberg, Anders
    Institutet för Folkhälsa och klinisk medicin, Enheten för medicin/Lungmedicin och allergologi, Umeå universitet.
    Wiinikka, Henrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Grönberg, Carola
    Energy Technology Centre, Piteå.
    Öhrman, Olov
    Bäfver, Linda
    SP Sveriges Tekniska Forskningsinstitut, SP Energiteknik.
    Rönnbäck, Marie
    SP Sveriges Tekniska Forskningsinstitut, SP Energiteknik.
    Ryde, Daniel
    SP Sveriges Tekniska Forskningsinstitut, SP Energiteknik.
    Johansson, Mathias
    SP Sveriges Tekniska Forskningsinstitut, SP Energiteknik.
    Pagels, Joakim
    Avdelningen för Ergonomi och Aerosolteknologi, Lunds Tekniska Högskola.
    Nordin, Erik
    Avdelningen för Ergonomi och Aerosolteknologi, Lunds Tekniska Högskola.
    Rissler, Jenny
    Avdelningen för Ergonomi och Aerosolteknologi, Lunds Tekniska Högskola.
    Swietlicki, Erik
    Avdelningen för Kärnfysik, Lunds tekniska högskola.
    Eriksson, Axel
    Avdelningen för Kärnfysik, Lunds tekniska högskola.
    Genberg, Johan
    Avdelningen för Kärnfysik, Lunds tekniska högskola.
    Pettersson, Esbjörn
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Larsson, Lennart
    Institutet för Laboratoriemedicin, Lunds universitet.
    Strand, Michael
    Avdelningen för Bioenergiteknik, Linnéuniversitet.
    Emissioner från småskalig värmeproduktion med biobränslen: Ett samordnat projekt som berör hälsopåverkande partikel- och tungmetallutsläpp från tradionella och alternativa biobränslen2011Rapport (Övrigt vetenskapligt)
  • 191.
    Boman, Christoffer
    et al.
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Nyström, Robin
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Wiinikka, Henrik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Grönberg, Carola
    Energy Technology Centre, Piteå.
    Öhrman, Olov
    Pettersson, Esbjörn
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Sandström, Thomas
    Institutet för Folkhälsa och klinisk medicin, Enheten för medicin/Lungmedicin och allergologi, Umeå.
    Blomberg, Anders
    Institutet för Folkhälsa och klinisk medicin, Enheten för medicin/Lungmedicin och allergologi, Umeå.
    Mudway, Ian S.
    King´s College London, MRC-HPA Centre for Environment and Health, School Biomedical & Health Science.
    Westerholm, Roger
    Institutet för Analytisk kemi, Stockholms universitet.
    Pagels, Joakinm
    Avdelningen för Ergonomi och Aerosolteknologi, Lunds Tekniska Högskola.
    Swietlicki, Erik
    Avdelningen för Kärnfysik, Lunds tekniska högskola.
    Genberg, Johan
    Avdelningen för Kärnfysik, Lunds tekniska högskola.
    Inverkan av förbränningsteknik och bränsle på hälsofarligheten av partikelemissioner från småskalig biobränsleeldning2011Ingår i: Emissioner från småskalig värmeförsörjning med biobränslen: Ett samordnat projekt som berör hälsopåverkande partikel- och tungmetallutsläpp från traditionella och alternativa biob, Umeå: Umeå universitet , 2011Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 192.
    Boman, Christoffer
    et al.
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Pettersson, Esbjörn
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Westerholm, Roger
    Analytical Chemistry, Arrhenius Laboratory, Stockholm University.
    Boström, Dan
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Nordin, Anders
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Stove performance and emission characteristics in residential wood log and pellet combustion: Part 1: Pellet stoves2011Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 25, nr 1, s. 307-314Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Stove performance, characteristics and quantities of gaseous and particulate emissions were determined for two different pellet stoves, varying fuel load, pellet diameter and chimney draught. This approach aimed at covering variations in emissions from stoves in use today. The extensive measurement campaign included CO, NOx, organic gaseous carbon, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), total particulate matter (PMtot) as well as particle mass and number concentrations, size distributions and inorganic composition. At high load, most emissions were similar. For stove B, operating at high residual oxygen and solely with primary air, the emissions of PMtot and particle numbers were higher while the particles were smaller. Lowering the fuel load, the emissions of CO and hydrocarbons increased dramatically for stove A, which operated continuously also at lower fuel loads. On the other hand for stove B, which had intermittent operation at lower fuel loads, the emissions of hydrocarbons increased only slightly lowering the fuel load, while CO emissions increased sharply, due to high emissions at the end of the combustion cycle. Beside methane, dominating VOCs were ethene, acetylene and benzene and the emissions of VOC varied in the range 1.1-47 mg/MJfuel. PAH emissions (2-340 µg/MJfuel) were generally dominated by phenantrene, fluoranthene and pyrene. PMtot (15-45 mg/MJfuel) were in all cases dominated by fine particles with mass median diameters in the range 100-200 nm, peak mobility diameters of 50-85 nm and number concentrations in the range 4×1013- 3×1014 particles/MJfuel. During high load conditions the particulate matter was totally dominated by inorganic particles at 15-25 mg/MJfuel consisting of potassium, sodium, sulfur and chlorine, in the form of K2SO4, K3Na(SO4)2 and KCl. The study shows that differences in operation and modulation principles for the tested pellet stoves, relevant for appliances in use today, will affect the performance and emissions significantly, although with lower scattering in the present study compared to compiled literature data.

  • 193.
    Boström, Dan
    et al.
    Umeå universitet.
    Boman, Christoffer
    Umeå universitet.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Effect of fuel additive sorbents (kaolin and calcite) on aerosol particle emission and characteristics during combustion of pelletized woody biomass2008Ingår i: From Research to industry and markets: 16th European Biomass Conference & Exhibition ; proceedings of the international conference held in Valencia, Spain, 2 - 6 June 2008 / [ed] J. Schmid, Florence: ETA - Renewable Energies , 2008, s. 1514-1517Konferensbidrag (Refereegranskat)
  • 194.
    Boström, Dan
    et al.
    Umeå universitet.
    Boström, Markus
    Umeå universitet.
    Skoglund, Nils
    Umeå universitet.
    Boman, Christoffer
    Umeå universitet.
    Backman, Rainer
    Umeå universitet.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Grimm, Alejandro
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ash transformation chemistry during energy conversion of biomass2010Ingår i: Proceedings of the International Conference on Impact of Fuel Quality on Power production and the Environment, 2010Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    There is relatively extensive knowledge available concerning ash transformation reactions during energy conversion of woody biomass. Traditionally, these assortments have constituted the main resources for heating in Sweden. In recent decades the utilization of these energy carriers has increased, from a low technology residential small scale level to industrial scale (e.g. CHP plants). Along this evolution ash-chemical related phenomena for woody biomass has been observed and studied. So, presently the understanding for these are, if not complete, fairly good. Briefly, from a chemical point of view the ash from woody biomass could be characterized as a silicate dominated systems with varying content of basic oxides and with relatively high degree of volatilization of alkali sulfates and chlorides. Thus, the main ash transformation mechanisms in these systems have been outlined. Here, an attempt to give a general description of the ash transformation reactions of biomass fuels is presented, with the intention to provide guidance in the understanding of ash matter behavior in the utilization of any biomass fuel, primarily from knowledge of the concentrations of ash forming elements but also by considering the physical condition in the specific combustion appliance and the physical characteristic of the biomass fuel. Furthermore, since the demand for CO2-neutral energy resources has increased the last years and will continue to do so in the foreseeable future, other biomasses as for instance agricultural crops has become highly interesting. Globally, the availability of these shows large variation. In Sweden, for instance, which is a relatively spare populated country with large forests, these bio-masses will play a secondary role, although not insignificant. In other parts of the world, more densely populated and with a large agricultural sector, such bio-masses may constitute the main energy bio-mass resource in the future. However, the content of ash forming matter in agricultural bio-mass is rather different in comparison to woody biomass. Firstly, the content is much higher; from being about 0.3 - 0.5% (wt) in stem wood, it can amount to between 2 and 10 %(wt) in agricultural biomass. In addition, the composition of the ash forming matter is different. Shortly, the main difference is due to a much higher content of phosphorus (occasionally also silicon) which has major consequences on the ash-transformation reactions. In many crops, the concentration of phosphorus and silicon is equivalent, which (depending on the concentration levels of basic oxides) may result in a phosphate dominated ash. The properties of this ash are in several aspects different from the silicate dominated woody biomass ash and will consequently behave differently in various types of energy conversion systems. The knowledge about phosphate dominated ash systems has so far been scarce. We have been working with these systems, both with basic and applied research, for about a decade know. Some general experiences and conclusions as well as some specific examples of our research will be presented

  • 195.
    Boström, Dan
    et al.
    Umeå university.
    Broström, Markus
    Umeå university.
    Lindström, Erika
    Umeå university.
    Boman, Christoffer
    Umeå university.
    Backman, Rainer
    Umeå university.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Grimm, Alejandro
    Ash transformation chemisty during energy conversion of agricultural biomass2009Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    There is relatively extensive knowledge available concerning ash transformation reactions during energy conversion of woody biomass. Traditionally, these assortments have constituted the main resources for heating in Sweden. In recent decades the utilization of these energy carriers has increased, from a low technology residential small scale level to industrial scale (i.e. CHP plants). Along this evolution ash‐chemical related phenomena for woody biomass has been observed and studied. So, presently the understanding for these are, if not complete, fairly good. Briefly, from a chemical point of view the ash from woody biomass could be characterized as a silicate dominated systems with varying content of basic oxides and with relatively high degree of volatilization of alkali sulfates and chlorides. Thus, the main ash transformation mechanisms in these systems have been outlined. However, since the demand for CO2‐neutral energy resources has increased the last years and will continue to do so in the foreseeable future, other biomasses as for instance agricultural crops has become highly interesting. Globally, the availability of these shows large variation. In Sweden, for instance, which is a relatively spare populated country with large forests, these bio‐masses will play a secondary role, although not insignificant. In other parts of the world, more densely populated and with a large agricultural sector, such bio‐masses may constitute the main energy bio‐mass resource in the future. However, the content of ash forming matter in agricultural bio‐mass is rather different in comparison to woody biomass. Firstly, the content is much higher; from being about 0.3 – 0.5% (wt) in stem wood, it can amount to between 4 and 10 %(wt) in agricultural biomass. Furthermore, the composition of the ash forming matter is different . Shortly, the main difference is due to a much higher content of phosphorus which has major consequences on the ash‐transformation reactions. In many crops, the concentration of phosphorus and silicon is equivalent, which (depending on the concentration levels of basic oxides) may result in a phosphate dominated ash. The properties of this ash are in several aspects different from the silicate dominated woody biomass ash and will consequently behave differently in various types of energy conversion systems. The knowledge about phosphate dominated ash systems has so far been scarce. We have been working with these systems, both with basic and applied research, for about a decade know. Some general experiences and conclusions as well as some specific examples of our research will be presented.

  • 196.
    Boström, Dan
    et al.
    Energy Technology and Thermal Process Chemistry, Department of Applied Physics and Electronics, Umea University.
    Eriksson, Gunnar
    Boman, Christoffer
    Energy Technology and Thermal Process Chemistry, Department of Applied Physics and Electronics, Umea University.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ash transformations in fluidized-bed combustion of rapeseed meal2009Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 23, nr 5, s. 2700-2706Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The global production of rapeoil is increasing. A byproduct is rapeseed meal that is a result of the oil extraction process. Presently the rapeseed meal mainly is utilized as animal feed. An interesting alternative use is, however, energy conversion by combustion. This study was undertaken to determine the combustion properties of rapeseed meal and bark mixtures in a bubbling fluidized bed, with emphasis on gas emissions, ash formation, -fractionation and -interaction with the bed material. Due to the high content of phosphorus in rapeseed meal the fuel ash is dominated by phosphates, in contrast to most woody biomass where the ash is dominated by silicates. From a fluidized bed combustion (FBC) point of view, rapeseed meal could be a suitable fuel. Considering FBC agglomeration effects, pure rapeseed meal is in level with the most suitable fuels, as earlier tested by the methods utilized in the present investigation. The SO2 emission, however, is higher than most woody biomass fuels as a direct consequence of the high levels of sulfur in the fuel. Also the particulate matter emission, both submicron and coarser particles, is higher. Again this can be attributed the high ash content of rapeseed meal. The high abundance of SO2 is apparently effective for sulfatization of KCl in the flue gas. Practically no KCl was observed in the particulate matter of the flue gas. A striking difference in the mechanisms of bed agglomeration for rapeseed meal compared to woody biomass fuels was also observed. The ubiquitous continuous layers on the bed grains found in FBC combustion of woody biomass fuels was not observed in the present investigation. Instead very thin and discontinuous layers were observed together with isolated partly melted bed ash particles. The latter could occasionally be seen as adhered to the quartz bed grains. Apparently the bed agglomeration mechanism, that obviously demanded rather high temperatures, involved more of adhesion by partly melted ash derived potassium-calcium phosphate bed ash particles/droplets than direct attack of gaseous alkali on the quartz bed grains forming potassium-calcium silicate rich bed grain layers. An explanation could be found in the considerable higher affinity for base cations of phosphorus than silicon. This will to a great extent withdraw the present basic oxides from attacking the quartz bed grains with agglomeration at low temperatures as a result.

  • 197.
    Boström, Dan
    et al.
    Umeå universitet.
    Eriksson, Gunnar
    Hedman, Henry
    Energy Technology Centre, Piteå.
    Boman, Christoffer
    Umeå universitet.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bench-scale fluidized bed combustion of rapeseed meal2008Ingår i: From Research to industry and markets: 16th European Biomass Conference & Exhibition ; proceedings of the international conference held in Valencia, Spain, 2 - 6 June 2008 / [ed] J. Schmid, Florence: ETA - Renewable Energies , 2008, s. 1380-1385Konferensbidrag (Refereegranskat)
  • 198.
    Boström, Dan
    et al.
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Grimm, Alejandro
    Boman, Christoffer
    Energy Technology and Thermal Process Chemistry, Umeå University.
    Björnbom, Emilia
    Chemical Engineering and Technology, Royal Institute of Technology.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Influence of kaolin and calcite additives on ash transformations in small-scale combustion of oat2009Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 23, nr 10, s. 5184-5190Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A growing interest has been observed for the use of cereal grains in small- and medium-scale heating. Previous studies have been performed to determine the fuel quality of various cereal grains for combustion purposes. The present investigation was undertaken in order to elucidate the potential abatement of low-temperature corrosion and deposits formation by using fuel additives (calcite and kaolin) during combustion of oat. Special emphasis was put on understanding the role of slag and bottom ash composition on the volatilization of species responsible for fouling and emission of fine particles and acid gases. The ash fractions were analyzed with scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), for elemental composition, and with X-ray diffraction (XRD) for identification of crystalline phases. The previously reported K and Si capturing effects of kaolin additive were observed also in the present study using P-rich biomass fuels. That is, the prerequisites for the formation of low melting K-rich silicates were reduced. The result of using kaolin additive on the bottom ash was that no slag was formed. The effect of the kaolin additive on the formation of submicrometer flue gas particles was an increased share of condensed K-phosphates at the expense of K-sulfate and KCl. The latter phase was almost completely absent in the particulate matter. Consequently, the levels of HCl and SO2 in the flue gases increased somewhat. The addition of both calcite assortments increased the amount of formed slag, although to a considerably higher extent for the precipitated calcite. P was captured to a higher degree in the bottom ash, compared to the combustion of pure oat. The effect of the calcite additives on the fine particle emissions in the flue gases was that the share of K-phosphate decreased considerably, while the content of K-sulfate and KCl increased. Consequently, also the flue-gas levels of acidic HCl and SO2 decreased. This implies that the low-temperature corrosion observed in small-scale combustion of oat possibly can be abated by employing calcite additives. Alternatively, if problems with slagging and deposition of corrosive matter at heat convection surfaces are to be avoided, kaolin additive can be utilized, on the condition that the higher concentrations of acidic gases can be tolerated.

  • 199.
    Boström, Dan
    et al.
    Umeå universitet.
    Grimm, Alejandro
    Lindström, Erica
    Umeå universitet.
    Boman, Christoffer
    Umeå universitet.
    Björnbom, Emilia
    Kungliga tekniska högskolan, KTH.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Abatement of corrosion and deposits formation in combustion of oat2008Ingår i: From Research to industry and markets: 16th European Biomass Conference & Exhibition ; proceedings of the international conference held in Valencia, Spain, 2 - 6 June 2008 / [ed] J. Schmid, Florence: ETA - Renewable Energies , 2008, s. 1528-1534Konferensbidrag (Refereegranskat)
  • 200.
    Boström, Dan
    et al.
    Umeå universitet.
    Grimm, Alejandro
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Skoglund, Nils
    Umeå universitet.
    Boman, Christoffer
    Umeå universitet.
    Öhman, Marcus
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Broström, Markus
    Umeå universitet.
    Backman, Rainer
    Umeå universitet.
    Ash transformation chemistry during combustion of biomass2012Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 26, nr 1, s. 85-93Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is relatively extensive knowledge available concerning ash transformation reactions during combustion of woody biomass. In recent decades, the use of these energy carriers has increased, from a low-technology residential small-scale level to an industrial scale. Along this evolution, ash chemical-related phenomena for woody biomass have been observed and studied. Therefore, presently the understanding for these are, if not complete, fairly good. However, because the demand for CO2-neutral energy resources has increased recently and will continue to increase in the foreseeable future, other biomasses, such as, for instance, agricultural crops, have become highly interesting. The ash-forming matter in agricultural biomass is rather different in comparison to woody biomass, with a higher content of phosphorus as a distinctive feature. The knowledge about the ash transformation behavior in these systems is far from complete. Here, an attempt to give a schematic but general description of the ash transformation reactions of biomass fuels is presented in terms of a conceptual model, with the intention to provide guidance in the understanding of ash matter behavior in the use of any biomass fuel, primarily from the knowledge of the concentrations of ash-forming elements. The model was organized in primary and secondary reactions. Restrictions on the theoretical model in terms of reactivity limitations and physical conditions of the conversion process were discussed and exemplified, and some principal differences between biomass ashes dominated by Si and P, separately, were outlined and discussed.

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