| 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. |
- Axelberg, Peter, et al.
(författare)
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A measurement method for determining the direction of propagation of flicker and for tracing a flicker source
- 2005
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Ingår i: CIRED. ; , s. 505-508
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Konferensbidrag (refereegranskat)abstract
- This paper describes a new and highly efficient measurement method (algorithm) that determines how flicker propagates throughout the network and also traces the dominant flicker source. The fundamental principle of the method is to use the fact that a flicker source produces an amplitude modulation in the voltage and current waveforms. The low frequency variations in voltage and current that cause flicker are retrieved in a demodulation and filtering process. By first multiplying the low frequency variations in voltage and current and then integrate, a new quantity, flicker power, is achieved. The sign and the magnitude of flicker power give the direction to the flicker source as well as tracing the dominating flicker source.
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| 3. |
- Axelberg, P.G.V., et al.
(författare)
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An algorithm for determining the direction to a flicker source
- 2006
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 21:2, s. 755-760
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes an algorithm for calculating the direction to a flicker source with respect to a monitoring point. The proposed algorithm is based on sampling of both the voltage and current. The low-frequency fluctuations in voltage and current are recovered from the input signals by demodulation, and passed through a bandpass filter as described in IEC 61000-4-15. A new quantity - flicker power - is defined from the output signals of the two filters. The direction to a flicker source is obtained from the sign of this flicker power. The proposed algorithm has been validated by simulations and several field measurements
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| 4. |
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| 5. |
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| 6. |
- Axelberg, P.G.V., et al.
(författare)
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Support vector machine for classification of voltage disturbances
- 2007
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Ingår i: IEEE Transactions on Power Delivery. - : IEEE. - 0885-8977 .- 1937-4208. ; 22:3, s. 1297-1303
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Tidskriftsartikel (refereegranskat)abstract
- The support vector machine (SVM) is a powerful method for statistical classification of data used in a number of different applications. However, the usefulness of the method in a commercial available system is very much dependent on whether the SVM classifier can be pretrained from a factory since it is not realistic that the SVM classifier must be trained by the customers themselves before it can be used. This paper proposes a novel SVM classification system for voltage disturbances. The performance of the proposed SVM classifier is investigated when the voltage disturbance data used for training and testing originated from different sources. The data used in the experiments were obtained from both real disturbances recorded in two different power networks and from synthetic data. The experimental results shown high accuracy in classification with training data from one power network and unseen testing data from another. High accuracy was also achieved when the SVM classifier was trained on data from a real power network and test data originated from synthetic data. A lower accuracy resulted when the SVM classifier was trained on synthetic data and test data originated from the power network.
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| 7. |
- Axelberg, P., et al.
(författare)
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Trace of Flicker Sources by using the Quantity of Flicker power.
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - : IEEE. - 0885-8977 .- 1937-4208. ; 23:1, s. 465-471
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Tidskriftsartikel (refereegranskat)abstract
- Industries that produce flicker are often placed close to each other and connected to the same power grid system. This implies that the measured flicker level at the point of common coupling (PCC) is a result of contribution from a number of different flicker sources. In a mitigation process it is essential to know which one of the flicker sources is the dominant one. We propose a method to determine the flicker propagations and trace the flicker sources by using flicker power measurements. Flicker power is considered as a quantity containing both sign and magnitude. The sign determines if a flicker source is placed downstream or upstream with respect to a given monitoring point and the magnitude is used to determine the propagation of flicker power throughout the power network and to trace the dominant flicker source. This paper covers the theoretical background of flicker power and describes a novel method for calculation of flicker power that can be implemented in a power network analyzer. Also conducted simulations and a field test based on the proposed method will be described in the paper.
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| 8. |
- Basu, Supratim, et al.
(författare)
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A novel common power factor correction scheme for homes and offices
- 2005
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 20:3, s. 2257-2263
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Tidskriftsartikel (refereegranskat)abstract
- This paper explores the approach of having a common Power Factor Correction circuit for domestic and commercial loads. This leads to lower harmonic distortion without the need to install (expensive) active rectifiers in each end-user device. The need for power-factor correction as well as a number of design options is discussed in this paper. The design and cost estimation of a common Power Factor Correction scheme and some reliability issues are discussed
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| 9. |
- Bollen, Math, et al.
(författare)
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A customer-oriented approach towards reliability indices
- 2007
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Ingår i: Conference proceedings. - Liege : AIM.
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Konferensbidrag (refereegranskat)abstract
- This paper introduces a reliability index that is directly linked to the satisfaction of individual customers with the experienced reliability of supply. The definition of the index is based on the observation that customers are satisfied as long as they have less than 3 interruptions per year, none of which lasts longer than 8 hours. The customer dissatisfaction index (CDI) is defined as the probability that this condition is fulfilled for a given customer. Mathematical expressions are obtained for the CDI; its relation with existing indices is studied; and the results of a case study in a medium-voltage distribution network are presented.
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| 10. |
- Bollen, Math, et al.
(författare)
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A framework for regulation of RMS voltage and short-duration under and overvoltages
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:4, s. 2105-2112
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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