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  • 351.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Larsson, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Aggregation and Amplification of Wind-Turbine Harmonic Emission in a Wind Park2015In: IEEE Transactions on Power Delivery, ISSN 0885-8977, E-ISSN 1937-4208, Vol. 30, no 2, p. 791-799, article id 7042349Article in journal (Refereed)
    Abstract [en]

    This paper presents measurements of harmonic and interharmonic current (with 5 Hz frequency resolution) in the complex plane. The complex currents are spread around a center point. For interharmonics this center corresponds with the origin of the complex plane. For integer harmonics this center is off-set from the origin. A goodness-of-fit test reveals that phase angles of most interharmonics are uniformly distributed. A Monte-Carlo simulation based on the measurements has been performed to study the aggregation of the emission from individual turbines to the public grid. Low-order integer harmonics show less cancellation compared to high-order harmonics. Interharmonics aggregate close to the square-root rule for uniform phase angles.

  • 352.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Larsson, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wind power harmonic aggregation of multiple turbines in power bins2014In: International Conference on Harmonics and Quality of Power. Proceedings: , p. 723-727, article id 6842922Article in journal (Refereed)
    Abstract [en]

    The paper presents current harmonic and interharmonic measurement of a Type-IV wind turbine. Characterizations and classifications have been performed with the representation of harmonics and interharmonics in a complex plane. The study of aggregations due to the summation of complex currents has been performed based on Monte-Carlo Simulation for harmonics and interharmonics. Aggregations occur less for low-order harmonics, more for high-order harmonics and most for interharmonics. Aggregations are shown to be largely independent of the produced power

  • 353.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Larsson, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    A statistic study of harmonics and interharmonics at a modern wind-turbine2014In: International Conference on Harmonics and Quality of Power. Proceedings: , p. 718-722, article id 6842921Article in journal (Refereed)
    Abstract [en]

    The work presents measurements of harmonics and interharmonics from a modern wind turbine over a period of several days, using a conventional power quality monitor. A statistical study has been performed to present the characteristics of the emission during the measurement. A variation of emission has been observed, especially for interharmonics within certain low-frequency bands and for the switching frequency. Multiple relations between voltage and current components have been presented, as well as multiple relations between the emission and the active-power production. Generally, harmonics are independent of the active-power, whereas interharmonics are dependent on it.

  • 354.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Larsson, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Measurements of harmonic emission versus active power from wind turbines2014In: Electric power systems research, ISSN 0378-7796, E-ISSN 1873-2046, no 108, p. 304-314Article in journal (Refereed)
    Abstract [en]

    This paper presents harmonic measurements from three individual wind turbines (2 and 2.5MW size). Both harmonics and interharmonics have been evaluated, especially with reference to variations in the active-power production. The overall spectra reveal that, emission components may occur at any frequency and not only at odd harmonics. Interharmonics and even harmonics emitted from wind turbines are relatively high. Individual frequency components depend on the power production in dierent ways: characteristic harmonics are independent of power; interharmonics show a strong correlation with power; other harmonic and interharmonic components present various patterns. It is concluded that the power production is not the only factor determining the current emission of a wind energy conversion system.

  • 355.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    A comparison study of harmonic emission measurements in four windparks2011In: 2011 IEEE Power and Energy Society General Meeting, Piscataway, NJ: IEEE Communications Society, 2011Conference paper (Refereed)
    Abstract [en]

    This paper presents measurements of harmonic current emissions up till 2 kHz from four different windparks in northern Sweden, all equipped with modern power-electronics converters. The measurement results are presented in different ways, including a method to quantify the impact on the grid and a method to show the variations in the spectrum with time. The results show that there exists different dominating harmonics in different windturbines and that the magnitudes of the individual frequency components vary strongly with time. Each turbine however shows a broadband component with superimposed narrowband components. The impact on the grid, with reference to permissible levels of voltage distortion, is biggest for the interharmonic components

  • 356.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Characteristic and non-characteristic harmonics from windparks2011In: Proceedings of CIRED 21st International Conference on Electricity Distribution, CIRED - Congrès International des Réseaux Electriques de Distribution, 2011, article id 0251Conference paper (Refereed)
    Abstract [en]

    This paper presents measurements of harmonic current emissions up till 2 kHz from four different windparks in northern Sweden, all equipped with modern power-electronics converters. A study of the four windparks was performed interms of 95% value of harmonic current spectrum and the minimum fault-level needed to fulfil the EN 50160 requirements on voltage distortion. The results show that there exists different dominating harmonics and fault-level requirements for different windturbines. Each turbine however shows a broadband component with superimposed narrowband components. The impact on the grid, with reference to permissible levels of voltage distortion, is biggest for the interharmonic components.

  • 357.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Comparison of harmonic emissions at two nodes in a windpark2012In: 15th IEEE International Conference on Harmonics and Quality of Power (ICHQP 2012), IEEE Communications Society, 2012, p. 313-319Conference paper (Refereed)
    Abstract [en]

    This work presents a comparison study of measurements of power quality, with emphasis on voltage and current distortion, at two locations in the same windpark, located in northern Sweden. Emissions at both locations are compared based on both harmonics and interharmonics. A complete picture of spectrum during the measurement is presented to show the variations of emission in the windpark. Some dominating harmonics are further analyzed.

  • 358.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Measurements at two different nodes of a windpark2012In: 2012 IEEE Power and Energy Society General Meeting, Piscataway, NJ: IEEE Communications Society, 2012Conference paper (Refereed)
    Abstract [en]

    This paper presents measurements of power quality, with emphasis on voltage and current distortion, simultaneously at two locations in the same windpark, located in northern Sweden. Both harmonics and interharmonics components are considered in the study. Similarities and differences between voltage and current distortion are presented in this paper and possible explanations are discussed. One of the conclusions is that there is no simple relation between voltage and current distortion in a windpark.

  • 359.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Measurements of four-windpark harmonic emissions in northern Sweden2012Conference paper (Refereed)
    Abstract [en]

    This paper presents measurements of harmonic current emissions up till few kHz from four different wind parks in northern Sweden, all equipped with modern power-electronics converters. Measurements have been performed with 10-minute time resolution between one and several weeks. The measurement results are presented in different ways, including a method to show the variations in the harmonic emissions with time. The results show that there exists different dominating harmonics in different wind turbines and that the magnitudes of the individual frequency components vary strongly with time. Each turbine however shows a broadband component with superimposed narrowband components.

  • 360.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wind power harmonic emission versus active-power production2014Conference paper (Refereed)
  • 361.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Yao, Liangzhong
    Alstom Transport Information Solution.
    Theoretical emission study of windpark grids: Emission propagation between windpark and grid2011In: Proceeding of the International Conference on Electrical Power Quality and Utilisation, EPQU, Piscataway, NJ: IEEE Communications Society, 2011, p. 559-564Conference paper (Refereed)
    Abstract [en]

    This paper presents the results from a theoretical study on the harmonic emission of a windpark in the frequency range up to 200 kHz. The calculations are based on the transfer function from an individual turbine to the pubic grid, expressed in the frequency domain. The model has been applied to a general windpark, for which a mathematical expression has been derived. The study provides relations between different parameters in the windpark and the transfer functions. An important conclusion from the study is that emission into the public grid is negligible for frequencies above a few kHz.

  • 362.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Cundeva, S
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Harmonic emission study of individual wind turbines and a wind park2013In: The Renewable Energies and Power Quality Journal (RE&PQJ), ISSN 2172-038X, E-ISSN 2172-038X, no 11Article in journal (Refereed)
  • 363.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Cundeva, S.
    University Sts. Cyrill and Methodias, Skopje, Institute of Electroheat Faculty of Electrical Engineering and Information Technology.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Measurements of harmonic and interharmonic emission from wind power systems2014In: Russian Electrical Engineering, ISSN 1068-3712, Vol. 85, no 12, p. 769-776Article in journal (Refereed)
    Abstract [en]

    With increasing amounts of wind power connected, the power system is impacted in a number of ways. In this paper, the emphasis is on one of those impacts: the harmonic and interharmonic emission from wind-power installations. The emission of individual wind turbines as well as from a wind park has been studied. The spectrum as a function of active-power has been studied. Various trends of emission according to the output power have been presented. For four modern wind turbines estimations have been done on the impact on the grid for each harmonic and interharmonic subgroup. The primary emission from a complete windpark due to the emission from the turbines has been analyzed

  • 364.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Cundeva, Snezana
    Institute of Electroheat Faculty of Electrical Engineering and Information Technology.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wahlberg, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Harmonic aspects of wind-power installations2013Conference paper (Refereed)
    Abstract [en]

    With increasing amounts of wind power connected, the power system is impacted in a number of ways. In this paper, the emphasis has been on one of those impacts: the harmonic emission from wind-power installations. The harmonic emission of individual wind turbines as well as from a wind park has been studied. For four modern wind turbines estimations have been done on the impact on the grid per harmonic and interharmonic group. The primary emission from complete windpark due to the emission from the turbines has been analyzed.

  • 365.
    Yang, Kai
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Schwanz, Daphne
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Harmonic aggregation and amplification in a wind-park2015Conference paper (Refereed)
    Abstract [en]

    This paper studies the harmonic emission in a wind park,using a current transfer function. The emission of anindividual wind turbine has been measured during aperiod of a few weeks covering all output productions.The wind park harmonic emission is analyzed by theaverage spectrum at the collection point. The amount ofemission of the wind park as a whole is modeled by astochastic method, based on the Monte-Carlo Simulation.The measured harmonics at wind turbines have beenanalyzed and compared with the simulated overallemission at the collection point of the wind park. Theresults will be showed by graphs and some discussionswill be made.

  • 366.
    Yang, Yongtao
    et al.
    STRI AB.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Considering a customer dissatisfaction index in the reliability of distribution networks with distributed energy resources2008In: Proceedings of the 10th International Conference on Probabilistic Methods Applied to Power Systems: PMAPS 2008, Piscataway, NJ: IEEE Communications Society, 2008, p. 1-8Conference paper (Refereed)
    Abstract [en]

    This paper proposes a new design guideline for reliability improvement of distribution networks using distributed energy resource (DER). The proposed guideline is advised to maintain CDI values of all customers under a certain pre-defined threshold value. The impact of the switching devices failure on the reliability is also considered and proper corrections are made on various threshold values within the guideline, therefore the obtained results will also be valid when considering non-ideal switching devices. The simulation results show that the guideline produces reasonably good results. Furthermore the proposed correction method for the calculation of non-ideal switching devices is validated.

  • 367. Zavoda, Francisc
    et al.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Rönnberg, Sarah
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    CIGRE/CIRED JWG C4.24, Power Quality and EMC Issues associated with future electricity networks: status report2016Conference paper (Refereed)
  • 368.
    Zavoda, Francisc
    et al.
    IREQ/I-IQ Canada.
    Bollen, Math
    STRI - Sweden.
    Tremblay, Mario
    IREQ/I-IQ Canada.
    The behavior of power distribution feeder dips2009In: CIRED 20th International Conference on Electricity Distribution: (CIRED 2009) ; Prague, Czech Republic, 8 - 11 June 2009, Red Hook, NY: Curran Associates, Inc., 2009, article id 0346Conference paper (Refereed)
    Abstract [en]

    This paper presents interesting results from a dip study that included events related to five distribution feeders with poor dip performance and one substation, which was supplying one of the feeders. Data stored in a SQL database was available for analysis and post treatment, with the following outcome: Statistics on recorded dips (type I, II and III) and short interruptions over one year period; Weather influence on dip behavior and statistics on dip occurred during stormy days and normal weather days; Sizing of SCADA system using dip and outage statistics Percentage of dips originating in transmission system among the dips recorded at substation and LV sites; Dip propagation from substation bus bars to the end of the feeder.

  • 369.
    Zavoda, Francisc
    et al.
    IREQ (HQ), Varennes.
    Langella, Roberto
    Second University of Naples.
    Lǎzǎroiu, George Cristian
    University Politehnica of Bucharest.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Rönnberg, Sarah
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Meyer, Jan Christian
    Technische Universitaet Dresden.
    Ciufo, Philip
    University of Wollongong.
    Power Quality in the Future Grid: Results from CIGRE/CIRED JWG C4.242016In: 2016 17th International Conference on Harmonics and Quality of Power, Piscataway, NJ, 2016, p. 931-936, article id 7783475Conference paper (Refereed)
    Abstract [en]

    This paper gives a status report on activities of CIGRE/CIRED JWG C4.24. The following issues are addressed in the paper: Introduction, scope of the report and terminology; New developments in power electronics (PE); Changes in probability of interference; Microgrids and PQ; Volt-VAR control and PQ; Feeder reconfiguration and PQ; Demand side management and PQ; New measurement techniques; New mitigation.

  • 370.
    Zavoda, Francisc
    et al.
    IREQ.
    Rönnberg, Sarah
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Meyer, Jan
    Technical University Dresden.
    Desmet, Jan
    Ghent University.
    CIGRE/CIRED/IEEE working group C4.24 - New measurement techniques in the future grid2015Conference paper (Refereed)
    Abstract [en]

    One of the issues that the joint working groupCIGRÉ/CIRED/IEEE JWG C4.24 will be addressing, isthe need in future networks for new measurementtechniques, more complex and more accurate, which willbe undergoing architecture reconfiguration (due tofeeder reconfiguration) and will be witnessing old andnew phenomena affecting the power quality. This papergives a comprehensive overview and betterunderstanding of the real challenges related tomeasurement techniques in future networks

  • 371.
    Zheng, Ruimin
    et al.
    University of Hongkong.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Harmonic resonances associated with wind farms2010Report (Other academic)
  • 372.
    Zheng, Ruimin
    et al.
    Department of Electrical and Electronic Engineering, University of Hong Kong.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Zhong, Jin
    STRI AB.
    Harmonic resonances due to a grid-connected wind farm2010In: 14th International Conference on Harmonics and Quality of Power (ICHQP), Piscataway, NJ: IEEE Communications Society, 2010, p. 1-7Conference paper (Refereed)
    Abstract [en]

    This paper studies the impact of a grid-connected wind farm on the harmonic resonances. The basic theory on the harmonic resonances is introduced as well as its consequences. The models of wind farm for resonance analysis are presented for both calculations and simulations. The resonance orders and amplifications of voltage distortion with different capacity of capacitor banks are studied under different operation modes. Several case studies with a 200 MW wind farm have been carried out to illustrate the methods for harmonic resonance analysis. 

  • 373.
    Zhong, Jin
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Wei, Ming
    The University of HongKong.
    Rönnberg, Sarah
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Towards a 100% Renewable Energy Power Generation in Sweden2016In: Meeting Sweden's current and future energy challenges, Luleå: Luleå tekniska universitet, 2016, Luleå: Luleå tekniska universitet, 2016Conference paper (Other academic)
  • 374. Čundeva, S
    et al.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Kokolanski, Ž
    Vuletić, J
    Krkoleva, A
    Immunity against voltage dips: main recommendations to stakeholders of the CIGRE/CIRED/UIE Joint Working Group C4.1102011Conference paper (Refereed)
  • 375. Čundeva, S
    et al.
    Bollen, Math
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Krkoleva, A
    Vuletić, J
    Kokolanski, Ž
    Djokić, S
    Improved understanding of compatibility issues regarding voltage dips: main contributions of the CIGRE/CIRED/UIE Joint Working Group C4.1102011Conference paper (Refereed)
5678 351 - 375 of 375
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  • ieee
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