• Energy Research

Purpose. Efficient use of natural energy resources is one of the priorities of the state policy in the sphere of universities and institutions of the Ministry of Education and Science of Ukraine. Besides search and development the new efficient and clean energy systems it is necessary to implement optimal management of the development and operation of existing facilities, reducing their energy costs. Purpose of this work is to develop consumption volume technology of electricity and heat by scientific departments of Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan (DNURT) for further finding the ways to reduce energy consumption. The problem is due to the specifics of University’s energy scheme. There is a difficulty for the installation of energy meters and data acquisition about their use in individual branches and structural units. At the same time it is impossible to assess qualitatively the energy position of scientific departments. Methodology. The method to determine the electricity and heat consumption for space heating of scientific departments at the university is based on «The intersectoral rules of electricity and heat energy for institutions and public sector organizations in Ukraine» and «Codes and regulations on rationing of fuel and heat energy for heating the residential buildings as well as for economic needs in Ukraine». Findings. Developed determining expenditure technology of electricity and heat for heating by scientific departments at the DNURT named after Academician V. Lazaryan allows obtaining data on energy consumption in individual units without direct measure and analyzing the effectiveness of energy saving technologies. Originality. It is represented by energy costs in the form of two components and these components are defined on the basis of the energy audit. This enables the energy inputs to implement energy efficiency measures in the research departments of the university. Practical value. The developed method can be used as practical tools to monitor energy consumption in the above mentioned university and in similar facilities.

One of the assumptions made during the modernization process of diesel shunting locomotives is the replacement of a diesel traction motor with a DC generator with an electric asynchronous traction motor. The article aimed to develop a method of selecting energy-efficient parameters of an asynchronous electric traction motor for diesel shunting locomotives, which will ensure that its operating energy efficiency will be as high as possible. The method was verified on the example of a locomotive series ChME3 (ЧMЭ3, ČME3, ČKD S200). It has been found that using a traction asynchronous electric drive on a ChME3 locomotive, its efficiency increases in comparison with DC electric motors by 3–5% under the long-term operation modes and by 7–10% during locomotive operation with traction at the adhesion limit. Using a new traction gearbox with a higher gear ratio expands the speed range in which the asynchronous traction drive operates with a high-efficiency factor. It is effective to use a traction asynchronous electric drive to modernize ChME3 diesel locomotives in case of their use under the modes requiring the implementation of maximum traction forces at low speeds. A further increase in the efficiency of the traction asynchronous electric drive is possible based on the optimal design of the wheel-motor unit and the asynchronous traction electric drive.

Abstract The relevance of the research lies in the development of the current question about the influence of microclimate quality on the efficiency of residential units. The aim of the study is to examine how the microclimate parameters affect the efficiency of residential buildings. Findings. The results obtained are essential for the design of energy-efficient and comfortable residential buildings. The scientific novelty and practical importance of research resides in the thorough study of microclimate in low-rise residential buildings. Microclimate deviation charts for residential buildings have been produced.

This work is aimed at developing a stand for tuning the fuel system of an internal combustion engine based on two electromagnetic retarders connected to the driving wheels of a car to simulate a load, and a microprocessor-based torque control system for each brake. In accordance with the terms of reference from the specialists of the automotive service center, such a stand should provide two main modes of operation: (1) stabilization of the speed of the drive wheels in the entire range of loads (fuel supply); (2) engine acceleration and deceleration according to linear tachograms in the range from minimum to maximum speed to determine the dependence of engine power and torque on speed. The purpose of this research is the synthesis of controllers, testing, the choice of the structural scheme, and the parameters of the control and data processing system in the stand for the precision tuning of internal combustion engines. Based on a preliminary analysis of the system, taking into account the mechanical connection of the wheels through the main gear and the car differential, the nonlinear dependence of the electromagnetic torque on the current and retarder speed, and subsequent experimental results, we obtained two types of controller—a third-order aperiodic transfer function and a fractional aperiodic transfer function of order 1.6. This made it possible to synthesize a family of controllers that ensure the operation of the stand in the required modes: synchronization of wheel speeds during engine acceleration; stabilization of the reference speed when the engine torque is changed from minimum to maximum due to fuel supply; measurement of the maximum power and torque of the internal combustion engine during the formation of a triangular tachogram with a given acceleration to compensate for the dynamic component of the torque due to mechanical inertia. The system with the PID controller configured in MATLAB in the “Tune” package has the best performance, but the smallest overshoot and the best dynamic accuracy are ensured by the PIDIγIµ fractional–integral controller, where the system is characterized by a fractional order of astaticism 1.6. Such a controller for each electromagnetic retarder serves as the basis of the microprocessor-based control, data acquisition, processing, graphical display system, and will also be used to develop a similar bench for tuning four-wheel-drive vehicles.

Rail is the most efficient and low carbon means of transport, but efforts are still being made to improve the energy efficiency of this sector. In Poland, one of the elements of the implementation of the energy transformation in rail is the “Green Railway” program, which assumes an increase in the share of renewable energy sources (RES) in the power supply structure of the sector to 50% in 2025 and 85% in 2030, and ultimately, to 100%. An increase in energy efficiency leads to a reduction in financial costs, and also contributes to improving the environment and, consequently, to enhancing the economic and social benefit through a cost–benefit analysis. Energy consumption in railway operations is characterized (unlike in construction) by being repetitive. This energy consumption is produced in four areas: in the movement of trains; in auxiliary systems in the trains; in auxiliary systems in the infrastructure (lighting consumption of tunnels or sections of track, point heating systems, the signaling and communication systems, etc.); and in stations, workshops and by other consumers. The aim of this article was to review modern technologies using renewable energy sources in rail transport for traction and non-traction customers.

Purpose. The study analyzed the possibility and conditions for the effective operation of heating systems during the transition of the heat-generating capacity to biofuels energy. The straw of cereal crops, which are prevailing in Dnipro region, is used for this. The main purpose is scientific calculation of opportunities and cost of specific measures for such a transition. As an example it was taken the boiler-room of campus at Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan (DNURT) that consumes natural gas. Methodology. The work analyses the legislative base of Ukraine, which promotes the using of renewable energy sources as fuel, as well as the incentive mechanisms for the development of this trend. The paper identifies opportunities of Prydniprovsk region to ensure straw supply for the boiler-room. Cost parameters of cargo transportation on the territory of Ukraine in 2016, which depend on the distance and the size of the trucks, are analysed. These indicators, as well as indicators related to its purchase, are considered together with energy potential of using the straw as fuel. Findings. With existing in Ukraine (as of 2016) the grain yielding capacity in the agriculture and cost indicators in the field of transportations, the transition of capacity share to biofuel is sufficiently profitable. The thermal power unit cost can be reduced fourfold. Originality. For the first time it is proposed to use the new integrated approaches to assess the cost of thermal power unit boiler with its transition to the use of renewable energy sources. The authors also proposed a new logistics delivery of these sources to the place of their application. From a technical and cost points of view it was determined the optimal order of capacity transfer for new renewable sources of energy in a given region depending on the structure of areas under crops and their productivity. Originality. The introduction of the proposed solutions and approaches to capacity boiler renewable energy sources can be realized with a relatively small investment and can provide significant economic benefits.

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.

This paper presents a novel approach to determining the ampacity of DC and AC railway overhead contact lines, considering both operational and design factors. The ampacity of contact lines is influenced by several design parameters, including materials, cross section and the number of catenary and contact wires, etc. Additionally, the permissible long-term and short-term current values, which correspond to the permissible temperatures defined by EN 50119:2020, are affected by operational factors such as ambient temperature, solar radiation, heat exchange conditions, wind speed, wear of contact wires. Existing methods for determining the ampacity of overhead contact lines often fail to account adequately for these critical factors and lack the necessary procedures to calculate the 30 min ampacity required by EN 50119:2020. In response, the method proposed in this study adapts the procedures of IEEE 738-2012 to the specific needs of railway contact lines, taking into account the effect of contact wire wear on current distribution and overall ampacity. The proposed method offers a more realistic and practical approach to determining the ampacity of contact lines, thereby enhancing the reliability and efficiency of the traction power supply infrastructure. This method could be useful for railway infrastructure managers to ensure the safe and efficient operation under varying environmental and operational conditions.

The analysis of the problem of innovative transformation of power supply networks of railways made it possible to scientifically substantiate the direction of research related to an optimal strategy for computer monitoring and intellectualization of the processes of power supply of traction substations of railways. Conceptual approaches to the formation of a new model of intellectualization of power supply networks have been developed. Differential models of high organization of synchronous vector measurements are proposed, allowing to determine the comprehensive information content of the primary data. Based on the concept of smart energy, a set of differential models and methods of harmonic and correlation analysis of anomalous and transient processes occurring in power systems has been developed. The REGINA computer system has been designed and manufactured to carry out, in real-time, intelligent monitoring, diagnostics, identification of accidents, optimization of power consumption and expanding the range of market services in managing railway power supply networks. The REGINA system complies with the requirements of ISO 9001: 2015 and the German certification body DOS. Many actual results obtained during the operation of the REGINA on the railways are presented.