Integrated use of Smart Grid technologies in railway traction networks

The purpose of the paper is to develop a methodology for modeling railway power supply systems equipped with a set of devices implemented on the base of smart grid technologies. The research is carried out using the Fazonord software package designed for modeling the modes of railway power supply systems in phase coordinates. The calculation model is implemented for the power supply system of a two-track section with five traction substations. The results obtained show that reliable and high-quality power supply of train traction and non-traction consumers can be ensured on the basis of the integrated use of active Smart Grid elements, such as a phase number converter, active harmonic conditioner, controlled reactive power source, and a distributed generation unit. Computer simulation allows to establish that in the absence of reactive power sources there are noticeable voltage fluctuations on 10 kV buses of non-traction consumers; the asymmetry is approaching the limit of normally acceptable values; disabling of the active filter results in the increase of the total harmonic coefficient of voltages up to 16%; if the entire complex of active devices is available, the high quality of electrical energy is achieved; the phase number converter is robust and features low sensitivity to the errors in parameter setting; voltage deviations caused by the limited variation range of reactive power in the reactive power source are short-term and do not exceed the values acceptable in practice. Thus, on the basis of Smart Grid technologies, distributed generation units can be connected directly to the traction network using a phase number conversion device formed according to the reciprocal Steinmetz circuit. Elimination of harmonic distortions created by rectifier electric locomotives is carried out by means of an active conditioner of higher harmonics. A controlled reactive power source can be used to maintain voltage levels.