Denna litteraturstudie undersöker Svenska kraftnäts påverkan på svenska fåglar, vilka fågelarter som påverkas mest, kollisioner med kraftledningar, metoder för att reducera antal kollisioner, störning vid anläggningsarbetet och hur kraftledningar kan främja svenskt fågelliv. Högspänningsledningar kan medföra kollisionsolyckor, habitatförluster och störning, men kan även generera artrika habitat. De mest drabbade arterna från kraftledingsolyckor i Sverige är rovfåglar, svanar, vit stork (Ciconia ciconia), trana (Grus grus) och ugglor. Kollisionsrisken påverkas av ålder, aktivitet, beteende, väderförhållanden, manövreringsförmåga, specifika områden, kraftledningshöjd och ledningstyp. För att effektivt minska antalet kollisioner kan fågelavvisare användas, som monteras på kraftledningar så att fåglar kan upptäcka dem. Kraftledningar kan förändra miljöer, men anläggningsarbete anses inte medföra störning som påverkar fåglar på populationsnivå. Lövsångare (Phylloscopus trochilus), svarthätta (Sylvia atricapilla), ringduva (Columba palumbus) och trädlärka (Lullula arborea) föredrar dessutom kraftledningsgator över andra miljöer i Sverige. Fynden i denna studie är komplexa och belyser vikten av framtida forskning på hur högspänningsledningar påverkar fågelliv.

Antal nyregistrerade laddbara personbilarbilar ökar märkbart för varje år.Enligt en prognos kommer cirka 2.5 miljoner laddbara bilar vara i trafik iSverige år 2030. Detta motsvarar hälften av personbilsflottan idag.Ökningen av laddbara bilar sker framför allt i elområden SE3 och SE4.Detta påverkar hur transmissionsnätet påverkas i framtiden där mängdeneffekt som ska transmitteras från norr till södra landet ökar omomständigheterna i nätet är samma som idag. I detta examensarbeteuppskattades först effektökningen orsakade av elbilar år 2030 för denämnda elområdena. Sedan modellerades transmissionsnätet i SE3 ochSE4 för att undersöka hur denna effektökning påverkar transmissionsnätetoch dess förluster.Resultatet visade att effektökningen kommer att belastatransmissionsnätet hårdare än idag. För effektöverföring mellan SE2 ochSE3 passeras den maximala överföringskapaciteten redan idag för vissatimmar av året. Resultatet i denna rapport visar att sådana timmar kommeratt vara betydligt fler för år 2030 och förlusterna kommer att öka. Detvisade sig att för SE4 kommer den maximala överföringskapacitetenräcka för år 2030. / The number of newly registered rechargeable passenger cars in Swedenincreases noticeably every year. According to a forecast, there will bearound 2.5 million cars in traffic in 2030. This corresponds to half of thepassenger car fleet today.The increase in rechargeable cars takes place above all in electricity areas:SE3 and SE4. This affects how the Swedish national grid is affected in thefuture, where the amount of power to be transmitted from the north to thesouth of the country increases if the conditions in the grid are the same astoday. In this bachelor thesis, the power increase caused by electric carsin 2030 was first estimated for the mentioned electricity areas. Then thepower transmission grid was modeled for SE3 and SE4 to investigate howelectric cars will affect the national grid and its losses.The result showed that the power increase will load the national grid moreheavily than today. For power transmission between SE2 and SE3, themaximum net transfer capacity is already exceeded for certain hours ofthe year. The result in this report shows that such hours will besignificantly more for the year 2030 and the losses in the grid willincrease. It turned out that for SE4, the maximum transmission capacitywill be sufficient for the year 2030.

Svenska kraftnät is responsible for the operation and development of the Swedish transmission grid. A large number of substations in the transmission grid are approaching their expected service lifetime and must be renewed in the coming years. When renewing substations, total and partial outages in operation are often unavoidable. These outages may cause downtime for any party connected to the substation, whether it be an electricity generation or consumption. A solution is to build a new substation while the old is still in operation. Upon completion, a transfer of operation can be done from the old to the new substation. This however requires laying claim to new land, which affects the local environment and can be a time-consuming process. In an effort to minimise the need for planned outages during substation renewals, Svenska kraftnät wants to investigate techniques for bypassing substations while also allowing the connected party to remain in operation. This thesis has evaluated two differing techniques that allow for substations and any connecting parties to remain mostly in full operation during station renewals. One technique involves constructing a temporary switchgear compartment using air-insulated apparatuses to bypass the station and connect the third party. The other technique uses a mobile gas-insulated switchgear to achieve essentially the same arrangement.  After studying cases where either technique has been employed in station renewals, it was concluded that a solution utilising air-insulated apparatuses is better in several aspects. While the two technologies achieved similar results, the air-insulated technology did so at a lower cost, offered more flexibility, and was easier to integrate into pre-existing stations. Furthermore, the gas-insulated technology required more specialised competence, possibly limiting the availability of qualified contractors. It was concluded that bypassing stations during renewal projects could provide several benefits in terms of less downtime and economical losses, while also minimising the need to claim new land. In order to optimise the method a supply of air-insulated apparatuses and construction materials necessary for the bypassing of a station should be established by Svenska kraftnät. This, mostly reusable, equipment would then be on stand-by, ready to use in future station renewals.

The thesis aims to examine the impact of climate change on line rating and to investigate the possibility of a potential increase of capacity of an overhead line. The line rating of an overhead line determines how much current can be transmitted in the line. The weather parameters which affect the line rating are ambient temperature, solar radiation, wind speed, and wind direction. If the line rating is adapted to weather conditions, it is important to be able to predict how the weather will change in the future. Therefore, the impact of climate change on weather parameters is investigated. The ambient temperature and solar radiation are expected to change between different scenarios. However, it is unclear how wind speed and wind direction will be affected. Climate scenarios are designed that take these findings into account. The results show that wind speed has, by a large margin from other weather parameters, the largest impact on the dynamic line rating. This is followed by the wind's angle of attack to the conductor, ambient temperature, and finally solar radiation. For the designed climate scenarios, the dynamic line rating is almost the same in each case, which means that the calculated change in ambient temperature and solar radiation has no significant effect on the line rating. To further increase the capacity of the overhead line, the line could be upgraded with a conductor with a larger cross-sectional area.