Andrey Kryukov

The objective of the research presented in this paper was to develop methods for simulating the operating conditions of traction power supply systems (TPSSs) equipped with asynchronous generators (ASGs), which may be driven by wind or hydraulic turbines as prime movers, thereby significantly reducing train traction energy costs and lowering carbon monoxide emissions. Using phase-coordinate methods and the Fazonord AC-DC industrial software package, simulations were performed for a TPSS configuration comprising three traction substations (TSs) with ASGs connected to the 6 kV busbars. The results demonstrate that connecting the ASG reduces the maximum active power flow from the utility grid by 27%, decreases peak losses in the 220 kV primary supply line by 44%, and lowers voltage unbalance levels at the 220 kV busbars by 71–76%. Additionally, electromagnetic safety conditions along the 220 kV overhead lines feeding the substations are improved, and the temperature at the hottest points of the traction transformers is reduced. The developed ASG models, implemented using three controlled current sources, are universal and can be applied to TPSSs of various configurations and design layouts.

Modeling ice-melting operation in conductors of a 6 kV DC overhead contact system | Kryukov | iPolytech Journal Моделирование режимов плавки гололёда на проводах контактной сети постоянного тока повышенного напряжения 6 кВ | Крюков | iPolytech Journal

The study presents the results of research aimed at developing digital models for determining the operating parameters of railway power supply systems equipped with distributed generation plants based on renewable energy sources (RESs). RESs can be used in railway transport to increase the reliability of power supply to facilities located in areas with insufficiently developed power grids. This primarily applies to consumers, for whom a power failure can lead to significant damage, accidents, and a threat to human life. RES can serve as independent power sources for special-group consumers and can increase energy conversion efficiency. Furthermore, large-scale implementation of renewable energy sources can significantly reduce energy supply costs and improve power quality. The study employs phase-coordinate modeling, which is characterized by the following features: a systems approach, which implies determining operating conditions while considering the properties and characteristics of complex traction and supply networks; versatility, which enables modeling of power supply systems of various structures and designs; and comprehensiveness, which involves calculating normal, emergency, and special operating parameters—crucial for scenarios such as ice melting on catenary wires. The modeling results obtained using the Fazonord AC-DC software (ver. 5.3.5.2) show that RES-based distributed generation plants provide a variety of beneficial effects: reduction in electricity consumption from power system networks; decrease in voltage unbalance and harmonic distortion on the busbars of regional windings of traction substations; and stabilization of voltage levels on current collectors of electric locomotives.

The growing importance of integrating renewable energy sources (RESs) into mainline railway traction networks stems from the sector’s substantial electricity demand, which is traditionally met by carbon-intensive thermal generation. This paper addresses the potential of wind power to enhance energy efficiency and reduce emissions in rail transport. It details the development of digital models for simulating DC traction power systems (TPSs) coupled with RESs, specifically wind turbines. Given the complexity of TPSs, effective integration requires digital modeling that accounts for their unique properties. The proposed methodology, based on phase coordinate algorithms, offers a universal and comprehensive framework. It enables the identification of various operational modes (normal, emergency, and special) for diverse network components, including traction networks, transmission lines, and transformers. These models were used to simulate real-world train operations, generating data on electrical parameter dynamics and transformer thermal conditions. The results confirm that wind integration can improve energy efficiency, validating the methodology’s practical applicability for RES projects in DC traction networks, including advanced high-voltage systems.

The paper presents a method for the coordinated tuning of automatic voltage regulation (AVR) and automatic speed control (ASC) systems for a group of generators operating in parallel at a power plant. The method also involves solving the optimization problem using a genetic algorithm. The possibilities of using lead-lag elements in AVR and ASC, which impart predictive properties and improve damping characteristics of the controllers, are also considered. A model of a power plant operating in parallel with an electric power system is presented. This model demonstrates effective damping of oscillations under large disturbances when the proposed method is used to adjust the AVR and ASC control coefficients, along with a self-tuning lead-lag element. In this case, voltage oscillations and frequency overshoot disappear, and there is a significant reduction in the maximum deviations of these parameters. In the illustrative case study, the coordinated tuning of the controllers provides a 6% increase in the transmitted power limit and, as a consequence, the enhancement of the stability margin of the electric power system.

The growing importance of integrating renewable energy sources (RES) into mainline railway traction networks stems from the sector's substantial electricity demands, traditionally met by carbon-intensive thermal generation. This paper addresses the potential of wind and solar power to enhance energy efficiency and reduce emissions in rail transport. It details the devel-opment of digital models for simulating DC traction power systems (TPS) coupled with RES, specifically wind turbines. Given the complexity of TPS, effective integration requires digital modeling that accounts for their unique properties. The proposed methodology, based on phase coordinates algorithms, offers a universal and comprehensive framework. It enables the identi-fication of various operational modes (normal, emergency, special) for diverse network com-ponents, including traction networks, transmission lines, and transformers. These models were used to simulate real-world train operations, generating data on electrical parameter dynamics and transformer thermal conditions. The results confirm that wind integration can improve energy efficiency, validating the methodology's practical applicability for RES projects in DC traction networks, including advanced high-voltage systems.

Power supply for traction substations (TSs) of AC railways has traditionally been provided by 110–220 kV overhead transmission lines (OHL). These OHLs can be damaged during strong winds and ice formation. Furthermore, these lines generate significant electromagnetic fields (EMFs), which adversely affect maintenance personnel, the public, and the environment. Mitigating the resulting damages requires the establishment of protection zones, necessitating significant land allocation. Enhancing the reliability of power supply to traction substations and reducing EMF levels can be achieved through the use of gas-insulated lines (GIL), whose application in the power industry of many countries is continuously increasing. The aim of the research presented in this article was to develop computer models for determining the EMF of a GIL supplying a group of traction substations, taking into account actual traction loads characterized by non-sinusoidal waveforms and asymmetry. To solve this problem, an approach implemented in the Fazonord AC-DC software package, based on the use of phase coordinates, was applied. This allowed for the correct accounting of the skin effect and proximity effect in the massive current-carrying parts of the GIL, as well as the influence of asymmetry and harmonic distortions. The simulation results showed that the use of GIL brings the voltage unbalance factors at the 110 kV busbars of the traction substations within the permissible range, with the maximum values of these coefficients not exceeding 2%. The results of the harmonic distortion assessment demonstrated a significant reduction in harmonic distortion factors in the 110 kV network for the GIL compared to the OHL. The performed electromagnetic field calculations confirmed that the GIL generates magnetic field strengths one order of magnitude lower than those of the OHL. The obtained results lead to the conclusion that the use of gas-insulated lines for powering traction substations is highly effective, ensuring increased reliability, improved power quality, and a reduced negative impact of EMF on personnel, the public, the environment, and electronic equipment.

The study was aimed at developing digital models that would provide a means to accurately determine the operating parameters of electrical grids connected to traction substations in the event of complex faults. To this end, an approach was used based on a multiphase phase-coordinate representation of elements comprising the electric power system; this approach was implemented using the Fazonord AC DC software. The following types of complex faults were considered: downed power line; double line-to-ground fault at different points of the power line connected to a transformer with an isolated neutral point; two simultaneous short circuits in the grid. The modeling confirmed the need to factor in the traction network when determining operating parameters in the event of complex faults. For comparison, similar calculations were performed for the case of its disconnection. For a downed power line, the difference between the calculation results obtained with the traction network taken into account and for the case of its disconnection amounted to 11%. In the case of a double line-to-ground fault, the difference in power line currents reached 13%. For simultaneous short circuits in the grid with an isolated neutral point, the corresponding parameter was equal to 22%. Digital models of electric power systems were developed; these models enable the correct determination of operating parameters in the event of complex faults, taking the traction network into account. Their use in the design and operation of high-voltage electrical grids will enable the accurate setting of relay protection and automation devices, which, in turn, can reduce accident damage and power outage time for electricity consumers.

The efficiency of using electric vehicles largely depends on the availability of charging stations in power supply systems (PSS). To improve the power quality and the ability to control power flows, charging stations can be connected via energy routers built on the basis of solid-state high-frequency transformers. The paper proposes incorporating an energy storage device in the DC circuit of the energy router to improve the reliability of the power supply. The paper presents the results of modeling the operation of a power system supplying DC charging stations based on an energy router with an energy storage device. The study aimed to test the efficiency of the developed regulation system of the energy router with an energy storage device and its impact on the voltage in the power supply system and harmonic distortion levels. An algorithm for stabilizing voltage in the DC and AC networks of the energy router is proposed relying on the transformation of three-phase coordinates a–b–c into the d–q–0 system. The diagrams and descriptions of the models of the power supply system with DC charging stations, as well as an energy router with an energy storage device and a converter for control in normal and emergency modes are presented. The modeling results reveal that the proposed regulator of the energy router with an energy storage device reduces voltage drops when connecting a high-power load and ensures acceptable power quality indicators to meet the criterion of harmonic components. By implementing the control system of the energy storage device within the energy router and electric vehicle charging stations, we can effectively maintain voltage at consumers during emergencies. Thus, the use of energy routers with an automatic voltage regulation system will ensure the sustainable development of modern power supply systems with the ability to connect renewable energy sources, energy storage devices, and electric vehicle charging stations.