The research thesis is based on the study of Kaohsiung MRT Orange Line. On condition that bilateral power is supplied during the target year, make two-minute interval as the background simulation, and use MATLAB & Simulink software for analysis tools. Through the establishment of the equivalent in the stray current model, discuss the original ground construction of Kaohsiung MRT Orange Line, and change the resistance of the track structure, in order to analyze whether that affects stray currents. Besides, simulate the maximum stray current density and its length in each station. To study cathode corrosion of underground metal pipeline due to stray current, the equivalent circuit model is applied for computer simulation. By changing the distance between the underground metal pipelines and MRT rail tracks the voltage potential of the pipe lines introduced by the stray current of MRT system is derived. The mitigation strategy of cathode corrosion due to stray current is also proposed in the thesis.

This thesis is to investigate the power quality problems for KMRT system and to derive the optimal strategy to mitigate the harmonic distortion. The mathematical models of dc network which includes the TSS, 3rd track and VVVF Converters will be derived. Based on the power system network configuration, the operation schedule and annual ridership of KMRT system, the ac/dc load flow analysis is executed to find the power demand and current harmonic components for each TSS and each BSS. The harmonic load flow analysis is then performed to solve the voltage harmonic distortion. The optimal planning of harmonic filters will be derived so that the proper locations and years for the harmonic filters to be committed can be determined. The active filters and high pass filters as well as the band pass filters are all considered in the study to achieve the best cost effective for harmonic filter investment. This thesis will also to analyze in the stray current for mass transit system the mathematical models of TSS rectification stations, 3rd rail, running rail, the insulation resistances between running rail, MRT structure and grounding are included in the computer simulation. The variation of stray current for the peak and off peak operation of KMRT system over each study year is derived. The sensitivity analysis of stray current with respect to the insulation level of running rail is executed . The nearby public pipes of the MRT network will be used for the analysis of cathode corrosion due to the stray current. Different strategies to mitigate the stray current are investigated.

This diploma thesis deals with the issue of EMC of tram vehicles and traction system. The first chapter defines the issues that are then dealt with in the thesis. The next chapter lists the objectives of the work. Subsequent chapters analyze the issues described in chapter 2. In the last chapter, a flow chart is proposed, which should serve as a tool to estimate the hazards of the traction drive due to induced bearing currents.

I denna rapport analyseras för- och nackdelar med eldistributionssystem av typ TN-C (fyrledarsystem) respektive TN-S (femledarsystem) system. Det finns olika uppfattningar om vilket system som är lämpligast att bygga ut i distributionsnätet (lågspänningsnätet) och i fastigheternas huvudledning. Med hjälp av litteraturstudier och kontakt med olika elföretag och elbolag har olika ståndpunkter diskuterats och därefter har en sammanställning av resultatet tagits fram. Enligt analysen är TN-C det lämpligaste alternativet att använda i distributionsnätet och TN-S bör användas i fastighetens huvudledning. Detta för att kunna uppnå en god och stabil elmiljö. Detta examensarbete skall underlätta val av teknik och förhoppningsvis öka kunskapen angående ämnet. / In this report analysis the advantages and disadvantages of the TN-C (four conductor system) and TN-S (five conductor system) system. There are different opinion about which system is most appropriate to use in the distribution network and the building main lines. With the help of literature studies and contacts with various power companies and electric companies different opinion have been discussed . TN-C is the most appropriate option in the distribution network and TN-S should be used in the building main lines. This for achieving high and stable electrical environment. This thesis will facilitate the choice of technology and hopefully increase the knowledge about the subject.