Hubskyi P. Increasing of the DC traction power supply system efficiency at high-speed traffic

The thesis is devoted to the solving of the actual scientific and applied task of increasing the energy efficiency of DC power traction systems by developing scientific principles for the construction of distributed power systems that fit into the existing infrastructure to provide high-speed traffic, which is essential for electric transport. In work on the basis of experimental research of voltage and power modes in the system of DC traction power supply was proved that classical systems of centralized power supply do not allow to provide the necessary conditions for the introduction of high-speed traffic on existing lines. Voltage values both on the buses of the traction load, and in the traction lines, have a significant range of oscillations. If there is a significant reserve of installed aggregate power at traction substations in Ukraine, there are no means of voltage modes regulation in the traction lines. Existing foreign and Ukrainian developments the energy efficiency increasing for DC traction power supply systems require significant capital investments and do not take into account the peculiarities of the organization of high-speed traffic. Therefore, it is necessary to develop energy-saving technology of distributed power with the maximum use of existing infrastructure, taking into account the features of the load of high-speed trains. For the first time were developed the scientific principles of energy-efficient systems of distributed traction. Firstly, it was proposed to make a shift from the centralized power supply system to the distributed one, with the preservation of the existing supply infrastructure of the traction network - the location of traction substations in place of existing, and one unit substations on the sectioning points. Secondly, was developed method of calculating of the instantaneous traction power supply schemes on the basis of the resistance functions by calculating of the traction substation’s power necessary to provide a mode of steady-state consumption during movement of the electric rolling stock with a given level of voltage losses. Also was proposed to use two rectifier units with a total capacity of 10 MW and 5 MW for one aggregate substation Furthermore, was developed the mathematical model for simulation ot the current and voltage in the traction network using nonlinear recurrent analysis, which allows to estimate the quality of the processes of electric power consumption and the area of sustainable operation of the traction power supply system. The structure of the model allows to identify the hidden components of the process. Also, was developed the method of ensuring the stability of the DC traction power supply system in the part of using a nonlinear voltage regulator. The author proved that regulator with nonlinear control laws has the best robustness and the area of voltage stability in the power network providing application of non-linear regulator is 3-4 times wider comparing with linear regulator. Implementation of the distributed power system allows to save annually on the test area 2,879 million UAH by reducing the cost of electricity losses in the power supply system.