Kosariev Y. Voltage mode improvement in the DC traction power supply system of the electrified railways

The dissertation studies the scientific and applied issues of supplying a particular range of voltage changes on the current collector of the electric motive power at the decentralized power system. The work analyzes the power supply system of the DC voltage mode of electric transport. The experiments show that the actual DC traction power supply is not capable of providing the sufficient traction net-work power while implementing the high-speed traffic. The mathematical model allows performing calculations of the distributed traction power supply system with alternative sources of electric power. It involves using the regularities of the change in the traction network resistance with any number of traction substations and boost points. In combination with the functions of current distribution and the distribution of subsystem potentials make it possible to formalize electrotechnical calculations of electric traction systems and proceed from discrete to continuous representation. The system of limiting the minimum voltage level on the current collector of the electric motive power is recommended to narrow the voltage variation range and reduce power losses in the traction network for 30 %. The rational level of the min-imum voltage value limits in the contact network of the distributed power supply system is determined; it is 93% of traction substation open-circuit voltage and determined by the criterion of minimum power losses in the traction network. Ensur-ing a rational level of voltage in the traction network allowed, performing the same train operation on the area, to reduce the energy losses by 29% compared with the voltage limitation in the traction network at 3000 V and 64% compared with the voltage limitation in the traction network at 2900 V. On the basis of the developed model for calculating the distributed traction power supply system, the sensory method was improved for optimization the location of the boost point installation. This method allows reducing the electric power consumption for trains traction and power losses in the traction network while minimizing the installed power of the boost points providing voltage level on the current collector of the electric motive power. In order to implement a decentralized power supply system, a structure is proposed to use the installation of the distributed solar power generators as a power source.