The use of specialized rail rolling stock which is used for transporting ore from the quarry to the crushing plant at mining enterprises is analyzed here. Electric locomotives with an asynchronous traction electric drive and an on-board energy storage system are considered for use. The calculated dependencies of the electric locomotive trac-tive power were analyzed and it was established that on flat sections of the track profile, the movement is carried out with a power that does not exceed 50% of the nominal one. The movement with the nominal power is carried out on the controlled uphill during the cargo half-passage. To ensure the necessary power for movement in such areas, the use of an on-board energy storage system is proposed, which should feed the traction system while limiting the power consumed from the catenary. This happens when the voltage on the pantograph drops to a minimum level. The aim of this work is to determine the on-board energy storage system parameters during the operation of the electric locomotive with limitation of the power consumed from the traction network. Mathemati-cal models of the energy exchange processes in the electric locomotive traction system have been developed. The criteria for comparing options for calculating the parameters of the on-board energy storage system have been proposed. The criteria take into account the reduction of energy consumption during movement, the efficiency of energy storage, and the complete use of the on-board energy storage system in terms of power and working energy capacity. Based on the calculation results, it was determined that the use of an energy storage device with a power of 3,540 kW and an operating energy capacity of 63.5 kWh provides a 10% reduction in energy consumption, which is being consumed while moving along the sample section of the road. The current that can be consumed by an electric locomotive with such parameters of the on-board energy storage system is limited by 600 A.

Determination of the working energy capacity of the on-board energy storage system of an electric locomotive for quarry railway transport during working with a limitation of consumed power

Д. Земський: ORCID 0000-0003-4322-0727; В. Сиченко: ORCID 0000-0002-9533-2897; Д. Босий: ORCID 0000-0003-1818-2490

Моделювання сумісної роботи систем зовнішнього та тягового електропостачання залізниць змінного струму для оцінки якості електроенергії у несиметричних режимах

Miniature fuses as an anti-damage subsystem perform the important function of protecting electronic devices and systems against permanent damage that may result in electric shocks, fire risks, etc. Their role becomes particularly important when they are installed in such special systems as electronic security systems (ESS). For this reason, there is a need for practical verification of their protective properties. The article presents the results of destructive tests of the circuit-breaking time of miniature fuse-links considered in terms of their usefulness in the ESS with the use of a passive experimental add-on, developed at the Military University of Technology in Warsaw. The characteristics of the measuring attachment circuit and the measurement methodology used were presented. Based on the obtained measurement points of the obtained time–current characteristics, an attempt was made to develop their mathematical model using numerical methods in the field of non-linear regression, using the least squares optimization method (Levenberg–Marquardt algorithm). An exemplary classification of miniature fuse-links has been proposed due to their protective properties of circuits in the context of their use in electronic security systems. The considerations were summarized with an economic analysis of the tested fuse links. The conclusions include proposals for changes to the provisions of the European standard PN-EN 50131-1:2009 “Alarm systems: Intrusion and hold-up systems Part 1: System requirements” and Polish Defence Standard NO-04-A004-8 2016 “Military facilities. Alarm systems. Part 8: Operation”.

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Method for Evaluating the Effectiveness of Electrical Circuit Protection with Miniature Fuse-Links

Nowadays, the quality of electrical energy really needs to be improved especially for industrial purposes that require a good level of reliability in the distribution of electrical energy. Maintenance of distribution transformers is routinely carried out to ensure that the quality of electrical energy produced is in accordance with standards. This maintenance is done using the customer’s load from the distribution transformer to the mobile substation transformer, that can be done using synchronization. This synchronization requires the same distribution transformer vector groups, otherwise it will produce non-standard output. The aim of this research is to determine the vector groups effect on parallel transformer installation system, the method to overcome the synchronous problem of different vector groups based on simulating and testing the synchronization of a 20 / 0.4 kV distribution transformer with the Dyn5 and Dyn11 vector groups. The results obtained from this research are two transformers that have different vector groups can be synchronized with an abnormal connection (changing the position of the secondary terminal cable connection and the primary terminal cable) so that it will produce the same voltage phase. This will abnormal treatment of distribution transformers maintenance that do not have a back-up transformer with the same vector group still can use the different vector group transformers.

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Distribution Transformer Synchronization Simulation with Two Different Vector Groups using the Matlab Simulink

Distribution Transformer Synchronization Simulation and Implementation with Dyn5 and Dyn11 Vector Groups using the MATLAB Simulink and TTR Test

The article is devoted to the experiment, what was performed on the local distribution networks with poor power quality. As a rule, these networks are subsystem of AC traction power supply system, and their design causes voltage unbalance and other power quality problems in consumers. Often, the network is powered by transformers with different vector groups, therefore their parallel operation is impossible. The purpose of the experiment is to assess the effect on energy quality of a regime with sources on both sides. The quality of electrical energy was estimated, considerable attention is devoted to unbalance voltage. Using the statistics methods measurement data are studied. During the experiment, the energy quality improved when the parallel mode was used. The concept of smart grid has been proposed to reduce energy losses for dynamic power management.

Energy Efficient Modes of Distribution Power Supply Systems with Different Vector Group of Transformer

The problems of storage and supplying the energy, together with reducing energy intensity for transport, are now crucial for developing sustainable and reliable transport systems. The energy network must be gradually adapted to new loads and power consumption patterns, especially in railways. The article aims to develop the simulation model to investigate the energy storage systems in its use in the electric transport infrastructure.
The authors review selected technical solutions for electric energy storage in transport. The theoretical aspects of energy exchange in the energy storage systems were presented as a base for a continuous simulation model of electric transport power supply. In the non-periodic random voltage input applied to the storage unit, it is pro-posed to use the calculation method based on the Duamel integral to analyze its charge-discharge processes. The resistance functions were applied to analyze the traction power supply mode with variable in time and space by active loads. The simulation showed that the direct connection of the unit to the traction network significantly reduces the traction energy consumption.



Efficiency of energy storage control in the electric transport systems

The mathematical model of thermal disintegration of rocks during the reaming of boreholes, which takes into account the compatibility of the thermogas dynamic problem for a high-temperature heat transfer agent and the thermal problem for the rock heated by this heat transfer agent, has been developed. The mathematical model is based on the laws of conservation of mass, quantity of motion and energy and takes into account the dependences for determining the thermal stresses and the temperature of brittle fracture of rocks. As a result of solving the equations of the mathematical model, the temperature distribution in the rock mass (magnetite quartzite) during heating in the process of borehole plasma reaming and productivity of the borehole plasma reaming process are obtained. Calculated and experimentally determined productivity of the process of plasma reaming of the borehole were compared.

Mathematical modeling of rocks plasma disintegration process at borehole reaming

The aim of the work is to develop an economically justified approach to the selection of renewable sources of electricity. This aim is achieved by construction an automated algorithm that takes into account a set of restrictions for creating the optimal structure of a photovoltaic station. The work confirms the influence of such factors on project implementation as: electricity consumption schedule, built-up area, photovoltaic station mounting system type, allocated amount of money for project implementation, fixed and variable costs for maintenance of photovoltaic station, cost of electricity. The results of an economically justified approach to the selection of renewable sources of electricity at a real photovoltaic station are given. Indicators such as pay-back period and cash flow were calculated, which show the feasibility of the proposed approach.

Dmytro O. Bosyi

Papers

Energy Efficient Modes of Distribution Power Supply Systems with Different Vector Group of Transformer

Efficiency of energy storage control in the electric transport systems

Mathematical modeling of rocks plasma disintegration process at borehole reaming

Renewable electricity sources selection based on the economy applied approach