Improving the quality of voltage in the system of traction power supply of direct current

Abstract

Purpose of the work is improved approaches to ensure the required quality parameters of voltage in the traction network based on modern technologies and equipment in the application of power distribution system. Actuality. The introduction of high-speed traffic, increase weight standards Train necessitates increasing the carrying capacity of railways. Often the carrying capacity of existing sections electrified at 3.0 kV DC power supply unit limits. Such limitations include voltage decrease on the electric current collector below the allowable value for the normal operation of 2700 (2900 for high-speed V) and heating the contact wires, thereby losing their mechanical strength. Existing power supply system of RS, which have considerable installed traction substations, can not provide the required level of power density traction network for high-speed movement within 1.5 - 2 MW / km and, respectively, the required voltage quality. At the same time, the daily loading of a powerful traction substations in providing intensive schedule of trains does not exceed 20-25%, while the energy loss in traction network peak load increases and reaches 10-15% of the energy consumed. Thus, the existing system of power traction networks is not sufficiently effective and economical, even with the application of existing methods to strengthen them. In our view, the main limiting factor for a given quality of voltage in the traction network is the use of centralized power. From this, the development of measures to improve the quality of voltage in the traction network in the implementation of high-speed traffic in a growing scarcity of energy resources is an urgent task. Scientific novelty. Using distributed power supply system with adjustable supply points combined into intelligent power supply, which enables adaptive change the characteristics of the transfer, conversion and consumption and optimize the mode of functioning of the traction power supply is suggested for improving the quality of voltage in the traction network in the implementation of high-speed and heavy traffic. Practical significance. Improving the quality of voltage in the traction network by using the proposed circuit design traction power supply will ensure the desired mode voltage and power characteristics of the traction network in the implementation of high-speed and heavy traffic while reducing electricity losses by 20-30%.

An influence of a complex modernization of the DC traction power supply on the parameters of an electric power system

“…Replacing 6-pulse rectifiers with 12-pulse rectifiers along with raising rated voltage of the traction network power supply is aimed at achieving the following effects [11][12][15][16][17][18][19][20][21][22]: • improving voltage stability, • reducing losses in the transmission and distribution of electricity, • reducing electricity deformations retrieved from a commercial power system.…”

Modeling of the Controlled Traction Power Supply System in the Space-Time Coordinates

“…14. The result of solving must be the control law of the reinforcement point that works as a part of the tracking system for the voltages mode. In general, the current of the reinforcement point may be defined as follows: is the voltage drop in the contact network while accounting for the circulating currents, which is defined by formula (2); in practice its value may be measured with that proposed in [14], a wireless measurement system; ( ) As can be seen from fig. 12 (a) the voltage values in each pantograph of the electric rolling stock does not fall below 2900 V (voltage limit in the pantographs of the electric rolling stock for highspeed or heavyweight movement), which indicates that the voltage stabilization system works acceptably.…”

Rational distribution of excess regenerative energy in electric transport systems on the basis of fuzzy logic application

“…Here it is possible to observe frequent unsuccessful acts of regenerative braking of the train, which termination is caused by achievement of voltage on a pantograph the maximal admissible value (4,0 kV) owing to absence in a regenerative zone of trains in the traction mode. In addition, the effectiveness of the modes of regeneration depends on the voltage level at the busbars of traction substations (Sychenko et al, 2015). In this case the energy saving effect from regeneration decreases as the generated energy is utilized by brake mechanisms of the vehicle.…”

“…It is mainly related with a time spread of processes of energy consumption and energy generation by the vehicles which are on a section in the traction and regenerative modes that is especially noticeable in the case of small traffic. Energy quality during regeneration on the buses of substations must also be taken into account (Sychenko et al, 2015). Complex application of the mentioned technologies can improve regenerative modes of the electric power on non autonomous electric transport.…”