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| 2. |
- Anatory, Justinian, et al.
(författare)
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The influence of load impedance, line length, and branches on underground cable power-line communications (PLC) systems
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:1, s. 180-187
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Tidskriftsartikel (refereegranskat)abstract
- An underground cable power transmission system is widely used in urban low-voltage power distribution systems. In order to assess the performance of such distribution systems as a low-voltage broadband power-line communication (BPLC) channel, this paper investigates the effects of load impedance, tine length, and branches on such systems, with special emphasis on power-line networks found in Tanzania. From the frequency response of the transfer function (ratio of the received and transmitted signals), it is seen that the position of notches and peaks in the magnitude are largely affected (observed in time-domain responses too) by the aforementioned network configuration and parameters. Additionally, channel capacity for such PLC channels for various conditions is investigated. The observations presented in this paper could be helpful as a suitable design of the PLC systems for better data transfer and system performance.
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| 3. |
- Anatory, Justinian, et al.
(författare)
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An experimental validation for broadband power-line communication (BPLC) model
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:3, s. 1380-1383
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Tidskriftsartikel (refereegranskat)abstract
- Recently, different models have been proposed for analyzing the broadband power-line communication (BPLC) systems based on transmission-line (TL) theory. In this paper, we make an attempt to validate one such BPLC model with laboratory experiments by comparing the channel transfer functions. A good agreement between the BPLC model based on TL theory and experiments are found for channel frequencies up to about 100 MHz. This work with controlled experiments for appropriate validation could motivate the application and extension of TL theory-based BPLC models for the analysis of either indoor or low-voltage or medium-voltage channels.
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| 4. |
- Anatory, Justinian, et al.
(författare)
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Broadband power-line communications : The channel capacity analysis
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:1, s. 164-170
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Tidskriftsartikel (refereegranskat)abstract
- The power line has been proposed as a solution to deliver broadband services to end users. Various studies in the recent past have reported a decrease in channel capacity with an increase-in the number of branches for a given channel type whether it is an indoor or low-voltage (LV) or medium-voltage (MV) channel. Those studies, however, did not provide a clear insight as to how the channel capacity is related to the number of distributed branches along the line. This paper attempts to quantify and characterize the effects of channel capacity in relation to the number of branches and with different terminal loads for a given type of channel. It is shown that for a power spectral density (PSD) between -90 dBm/Hz to - 30 dBm/Hz, the channel capacity decreases by a 20-30 Mb/s/branch, 14-24 Mb/s/branch, and a 20-25 Mb/s/branch for an MV channel, LV channel, and indoor channel, respectively. It is also shown that the channel capacity is minimum when the load impedance is terminated in characteristic impedances for any type of channel treated here. It is shown that there could be a significant loss in channel capacity if a ground return was used instead of a conventional adjacent conductor return. The analysis presented in this paper would help in designing appropriate power-line communication equipment for better and efficient data transfer.
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| 5. |
- Anatory, Justinian, et al.
(författare)
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Expressions for Current/Voltage distribution in broadband power-line communication networks involving branches
- 2008
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 23:1, s. 188-195
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Tidskriftsartikel (refereegranskat)abstract
- Estimation of electromagnetic (EM)-field emissions from broadband power-line communication systems (BPLC) is necessary, because at its operating frequencies, the radiated emis sions from BPLC systems act as sources of interference/crosstalk to other radio-communication systems. Currently, the transmission-line (TL) system used for BPLC is complex, involving arbitrarily/irregularly distributed branched networks, arbitrary termination loads, varying line lengths, and line characteristic impedance. In order to study the electromagnetic-compatibility (EMC) issues associated with the radiated emissions of such complex BPLC networks, knowledge of current and voltage distributions along the length of the power-line channels is needed. This paper attempts to derive and present generalized expressions for either the current or voltage distribution along the line (whose TL parameters are known) between the transmitting and receiving ends for any line boundary condition and configuration based on the TL theory. The expressions presented in this paper could be beneficial for direct calculation of EM emissions from BPLC systems.
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| 6. |
- Anatory, Justinian, et al.
(författare)
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The effects of load impedance, line length, and branches in the BPLC transmission-lines analysis for-medium-voltage channel
- 2007
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 22:4, s. 2156-2162
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the effects of load impedance, line length and branches on the performance of medium-voltage power-line communication (PLC) network. The power-line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude and phase responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. These are observed in the time domain responses too. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
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| 7. |
- Anatory, Justinian, et al.
(författare)
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The effects of load impedance, line length, and branches in typical low-voltage channels of the BPLC systems of developing countries : transmission-line analyses
- 2009
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Ingår i: IEEE Transactions on Power Delivery. - 0885-8977 .- 1937-4208. ; 24:2, s. 621-629
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the influence of line length, number of branches (distributed and concentrated), and terminal impedances on the performance of a low-voltage broadband power-line communication channel. For analyses, the systems chosen are typical low-voltage power-line networks found in Tanzania. The parameters varied were the network's load impedances, direct line length (from transmitter to receiver), branched line lengths, and number of branches. From the frequency responses of the transfer functions (ratio of the received and transmitted signal), it is seen that the position of notches and peaks in the amplitude responses are affected by the aforementioned network parameters and topology. As a result, the time-domain responses are attenuated and distorted. Time-domain responses of power-line channels under various conditions are also investigated for a given pulse input at the transmitter. The observations presented in this paper could be useful for suitable power-line communication system design.
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| 8. |
- Wyss, Ramon Alexander, et al.
(författare)
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Mutual innovation capacity building through challenge driven education for sustainable development in an international framework
- 2019
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Ingår i: 12th international conference of education, research and innovation (ICERI 2019). - : IATED Academy. - 9788409147557 ; , s. 5209-5219
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Konferensbidrag (refereegranskat)abstract
- The KTH Royal Institute of Technology and the University of Dar es Salaam (UDSM) have successfully developed a new educational model, 'challenge driven education' (CDE). The Model comprises the following building blocks: Integrating societal challenges into the regular curriculum, close collaboration with external stakeholders 'the challenge owners' through the design thinking methodology, international and cross disciplinary student teams that develop solutions to the formulated challenges, teacher training modules that support the pedagogical learning and interaction with external stakeholders. The formulated challenges as well as the proposed solutions shall contribute to the sustainable development goals (SDGs) as formulated by the UN agenda 2030.The ambition of the program is to develop student and teacher skills that can tackle the challenges of our time, like the sustainable development goals. The program is developed through a strategic partnership of KTH Royal Institute of Technology and the College of ICT of University of Dar es Salaam, UDSM supported by a STINT grant (The Swedish foundation for international cooperation in research and higher education). External stakeholders like the Dar es Salaam water and sewage authority, DAWASA, have defined challenges like clean water supply of Dar es Salaam. Students and teachers develop actionable problem statements in a design thinking process together with DAWASA, the external stakeholder. Student teams of UDSM and KTH develop proposed solutions to the formulated challenges in their final year project. Implementation of the proposed solutions by external stakeholders generates steps towards a sustainable development. In similar fashion, students from UDSM come to Stockholm KTH to participate in challenge based courses developing solutions of the sustainability challenges of the Swedish society. The key contribution to society is students that have become confident of their skills and ability to work for a sustainable future, an academia that interacts directly with external stakeholders, integrating their challenges into the learning curriculum and societal stakeholders learning to interact with the university. The model is transferable and scalable. The presentation reports the successful implementation of the project at UDSM and KTH and report learning outcomes and impact on society. A teacher training book, guide to challenge driven education has been developed [1] prior to the project start, which has been used in the project and which can be downloaded from the KTH web, see also https://www.kth.se/challenge
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