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Ronnberg S.K.,Lulea University of Technology | Bollen M.H.J.,Lulea University of Technology | Bollen M.H.J.,Stri Ab | Wahlberg M.,Lulea University of Technology | Wahlberg M.,Skelleftea Kraft Elnat AB
IEEE Transactions on Power Delivery | Year: 2011

This paper discusses some of the electromagnetic-compatibility issues concerning the use of power lines for communication. Based on a series of measurements performed in a laboratory environment and in the field, five different types of interactions between communication and end-user equipment are distinguished. Measurement examples are shown for several of these types. It is concluded that the creation of a low-impedance path by end-user equipment is the main cause of interference. © 2011 IEEE.

Larsson E.O.A.,Lulea University of Technology | Bollen M.H.J.,Lulea University of Technology | Bollen M.H.J.,Stri Ab | Wahlberg M.G.,Lulea University of Technology | And 3 more authors.
IEEE Transactions on Power Delivery | Year: 2010

This paper presents different methods to describe voltage and current distortion in the frequency range 2 to 150 kHz. The timefrequency 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. © 2010 IEEE.

Yang K.,Lulea University of Technology | Bollen M.H.J.,Stri Ab | Larsson E.O.A.,Lulea University of Technology
IEEE Transactions on Power Delivery | Year: 2015

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 to the origin of the complex plane. For integer harmonics, this center is offset 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. © 1986-2012 IEEE.

Bollen M.H.J.,Lule University of Technology | Bollen M.H.J.,Stri Ab
Synthesis Lectures on Power Electronics | Year: 2011

This book links the challenges to which the electricity network is exposed with the range of new technology, methodologies and market mechanisms known under the name "smart grid." The main challenges will be described by the way in which they impact the electricity network: the introduction of renewable electricity production, energy efficiency, the introduction and further opening of the electricity market, increasing demands for reliability and voltage quality, and the growing need for more transport capacity in the grid. Three fundamentally different types of solutions are distinguished in this book: solutions only involving the electricity network (like HVDC and active distribution networks), solutions including the network users but under the control of the network operator (like requirements on production units and curtailment), and fully market-driven solutions (like demand response). An overview is given of the various solutions to the challenges that are possible with new technology; this includes some that are actively discussed elsewhere and others that are somewhat forgotten. Linking the different solutions with the needs of the electricity network, in the light of the various challenges, is a recurring theme in this book. Copyright © 2011 by Morgan & Claypool.

Yang K.,Lulea University of Technology | Bollen M.H.J.,Lulea University of Technology | Bollen M.H.J.,Stri Ab | Larsson E.O.A.,Lulea University of Technology | And 2 more authors.
Electric Power Systems Research | Year: 2014

This paper presents harmonic measurements from three individual wind turbines (2 and 2.5 MW 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 different 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. © 2013 Elsevier B.V.

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