The Budapest Metro Line 4 is a very large and long-delayed project. More than three decades passed between the first idea and the start of construction. Since October 2011, I participated the power utility installation works, as the employee of Siemens Zrt.
The theme of this thesis is the simulation of the DC traction system, with the aim to see the effects made by the trains on the power supply system and the under traffic relations as well. The goal is to estimate the parameters, what make the consumption decreasing.
The metro is a special, highly komplex type of the urban public transportation.
The most relevant part is the power supply system , which ensures that the energy absorbed from the urban medium voltage network reach the third rail, from which then the train can use it.
There are different voltage levels in the network, and alternating current and direct current as well. The most important parts of the system is 10 kV distribution , the distribution of 0.4 kV and the 800 volt traction field,the auxilary transformers, the two traction transformers and rectifiers .
The case study is divided into two parts. The first step was the scaling of the electric traction cables. There were many different circumstances and parameters,like the realtive position of the cables, the temperature and the type of the cables, which influenced the calculations. The second step was to examine the performance conditions. For the analysis, I used a program written in MATLAB code. The baseline data were the tractive and braking P-V diagrams of the train, and the points of the line in meters. Depend on the number of trains operating on the line and the time spend on stations, the program could calculate the ideal follow-up times , which can be an important consideration when planning the schedule, and making the operation more energy efficient .