Increasing the electrical energy efficiency in rail systems

The concept of energy efficiency can be defined as the reduction of the amount of energy used without decreasing utility, quality and continuity in operation. One of the most important expenses of railway transportation systems, where the initial investment costs are extremely high, is the energy consumption costs. Therefore, the efficient use of energy is of great importance. Electric power demand and energy consumption in rail systems are changing depending on time, network, trains, number of passengers and operating systems. Since the interactions of all subsystems that make up the rail system are complex, it is difficult to predict and evaluate energy consumption. For this reason, it is possible to improve energy efficiency by carrying out detailed studies, using appropriate methods and performing precise analysis of the results obtained. Traffic criteria, environmental pollution caused by fossil fuels and economic problems those cause significant problems in big cities and decrease the quality of life lead to the increasing percentage of rail transit systems in public transportation. However, the magnitude of the energy consumption of rail system networks and the need to use it as efficiently as possible is an another problem. When evaluated from the point of our country, Istanbul is an important center in terms of population, urban rail transport systems and energy consumption. Istanbul urban rail public transport system, which is approximately 149 kilometers long, consumes nearly 300 million kWh energy annually. Consumed energy distributions vary on tram and subway lines. For example, 55% of the energy consumed on subway lines is used for trains to move, while 45% is used for internal needs. For rail systems such as trams, this ratio is used as 95% for trains and 5% for internal requirements. Along with the rail systems that continue to be constructed rapidly, Istanbul is planning to complete many new lines at the final destination after 2023. However, the length of the line is expected to be 1000 km. Thus, energy saving studies are very important in rail systems. In this thesis study, general factors affecting the energy consumption of traction and fixed installations in urban rail systems will be given. Then, the M1 line selected as the model will be modeled on the RAILSIM program and DC load flow analysis will be performed. Simulation studies will be performed to increase energy efficiency for this line. Afterwards the M5 line will be modeled on the ETAP (Electrical Power System Analysis & Operation Software) program and the MV (Medium Voltage) and LV (Low Voltage) side load flows, transformer and cable loads and losses will be examined. The various operating scenarios will be repeated on the simulation to determine the optimal operating scenario for the line.