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Showing result 1 - 5 of 9 swedish dissertations matching the above criteria.

2. 1. Sustainability performance of multi-utility tunnels : Sustainability assessments for furthering knowledge and understanding

   Author : Filip Bergman; Joakim Johansson; Niclas Svensson; Stefan Anderberg; Sofia Lingegård; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multi-utility tunnel; Cable and pipe networks; Subsurface infrastructure; Sustainability assessment; Urban underground;

   Abstract : The multi-utility tunnel has received increased attention as an alternative method for the installation of subsurface infrastructure for the distribution of electricity, water, sewage and district heating. In previous research, the multi-utility tunnel (MUT) has been described as a more sustainable technology compared to the conventionally used technique where the cables and pipes are placed with open-cut excavation (OCE), especially when the entire life cycle is taken into account. READ MORE

4. 2. Novel Thermoplastic Material Concepts for High Voltage Cable Insulation - Engineering Immiscible Blends for a Sustainable Future

   Author : Yingwei Ouyang; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polypropylene; polymer blends; thermoplastic; copolymer; high-voltage power cable insulation; polyethylene;

   Abstract : To cope with our growing demand for energy in a sustainable way, efficient long-distance power transmission via high voltage direct current (HVDC) cables is crucial – these cables facilitate the integration of renewable energy into our power networks. For reliable and efficient power transmission, underground and undersea cables require robust insulation materials that possess a high level of mechanical integrity, a low direct-current (DC) electrical conductivity and a high thermal conductivity at the elevated temperatures experienced during cable operation. READ MORE

5. 3. Electromagnetic Interference in Distributed Outdoor Electrical Systems, with an Emphasis on Lightning Interaction with Electrified Railway Network

   Author : Nelson Theethayi; Rajeev Thottappillil; Farhad Rachidi; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Electromagnetic Compatibility EMC ; Lightning; Lightning Protection; Transmission Lines; Electromagnetic Wave Propagation; Underground Cables; Grounding; Electromagnetic Transients; Electromagnetic Interference; Shielding Effectiveness; Railway Systems; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : This thesis deals with the electromagnetic compatibility (EMC) problems of distributed electrical networks, especially that caused by lightning to electrified railway. Lightning transients were found to damage important devices that control train movements, causing traffic stoppage and delays. READ MORE

6. 4. Managing uncertainties through efficient calculation of transients and harmonic propagation in power systems

   Author : Oscar Lennerhag; Math Bollen; Jan Lundquist; David Thomas; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Overvoltages; harmonics; uncertainties; stochastic methods; Electric Power Engineering; Elkraftteknik;

   Abstract : The electric power system is undergoing changes including large-scale introduction of renewable energy sources together with HVDC/FACTS, changes in the network such as increased amount of high voltage cables, industrial electrification, and changes in the load composition. These changes will impact the system in different ways and lead to challenges that must be addressed to facilitate planning, dimensioning, and operation of the system in a secure and economical way. READ MORE

7. 5. Feasibility of HVDC for city infeed

   Author : Paulo Fischer de Toledo; KTH; []
   Keywords : ;

   Abstract : It is well recognized that direct current and direct voltageoffer special advantages for both land and sea cable systems,both with regard to power transmission capability, losses, aswell as possible transmission length due to no capacitivecurrents. As cable systems were used very early in largecities, one of the first applications considered for HVDC wasto use it for city infeed and some schemes were also built. READ MORE