A method is described for the computer-aided layout of printed wiring boards. The type of board considered is a single sided board containing discrete components. The required input for the layout algorithm is coded from the relevant circuit diagram, together with a description of the component dimensions. This information is then stored within the computer in a data structure. The circuit components and their interconnections are represented by a set of nodes and branches. The principles of graph theory are used to construct an abstract model of the layout. A number of the nodes and branches of the circuit are first used in the construction of a planar graph. A method is then described for inserting the remaining branches into the graph to form a "pseudo planar graph". This represents a set of components and conductor paths which can be laid out on a single sided board without intersections. The number of conductor crossings is thus minimised before the actual layout commences. An algorithm is then described for automatically constructing a board layout from the pseudo planar graph. The relative interconnections are already known so the placement of components and routing of conductor paths can proceed simultaneously. The layout is therefore constructed in a series of logical steps working across from one edge of the board to the other. This approach contrasts with the more usual methods of layout in which components are placed first, followed by a search for conductor routes. The layout algorithm is also provided with facilities for man-machine interaction by means of a graphical display and light pen. Interaction allows the user to alter the positions of components during the construction of the layout. Thus the skill and experience of the user can be combined with the speed and accuracy of the automatic algorithm. Interaction also enables special conditions to be incorporated into the layout which would otherwise entail considerable programming effort. Three different circuits are used to test the layout algorithm. The results are shown for layouts constructed both automatically and by the use of interaction. One layout is also compared with a manually-produced layout of the same circuit. The results show that a feasible method has been developed for the layout of printed wiring boards by computer. Comparable results are produced in considerably less time than normal layout methods.

Detta examensarbete är gjort på uppdrag av ABB i Ludvika. ABB har fått en beställning på en uppgradering av en högspänd likströmstation, på engelska High Voltage Direct Current (HVDC). Det finns huvudsakligen två olika tekniker gällande HVDC. Det är HVDC med Line Commutated Converters (LCC) och HVDC med Voltage Source Converters (VSC). LCC-tekniken är den äldsta och mest använda tekniken och är den teknik som stationen som uppgraderas använder. VSC-HVDC är en något nyare teknik som har fördelen att den inte kräver ett genererande nät på båda sidor av HVDC-länken men nackdelen att den inte klarar av lika höga effekter som LCC gör. Den har med dessa egenskaper blivit en populär teknik att använda för att till exempel överföra energi från vindkraftsparker ute till havs in till fastlandet eller för att förse oljeplattformar med energi. VSC-tekniken introducerades för första gången 1997 av ABB där den går under namnet HVDC-Light. Den aktuella HVDC-länken är en förbindelse mellan två länder och har en överföringskapacitet på totalt 600 MW. Uppgraderingen innefattar även uppdatering av befintliga scheman för att de skall finnas tillgängliga i den nya programvaran Engineering Base. Ritningarna har ritats i Microsoft Visio. Den utrustning som har ritats om och behandlas i denna rapport gäller utrustningen på likströmssidan av HVDC-stationen. Det innefattar jordknivar, frånskiljare, strömtransformatorer, spänningsdelare, överströmsskydd och genomföringar. / This thesis was conducted on behalf of ABB in Ludvika. ABB has received an order for an upgrade of a high voltage direct current (HVDC) station. There are two main technologies that HVDC is based on; line commutated converters (LCC) and voltage source converters (VSC). The LCC technology is the oldest and most widely used. It's also the technology that the upgraded station is based on. VSC HVDC is a newer technology that has the advantage of not requiring a generating power grid on both sides of the HVDC link but has the disadvantage that it cannot handle as high power as LCC can. With these qualities it has become a popular technology to use to transfer energy from offshore wind farms to the mainland or to provide oil platforms with energy. VSC technology was first introduced in 1997 by ABB where it is called HVDC Light. The revised HVDC link is a connection between two countries and has a total power transmission of 600 MW. The upgrade also includes updating existing circuit diagrams for the HVDC station to be available in the new software Engineering Base. The circuit diagrams have been drawn in Microsoft Visio. The equipment which have been designed and examined in this report applies to equipment on the DC side of the HVDC station. This includes grounding knives, disconnectors, power transformers, voltage dividers, current protection units and wall bushings.