Electricity supply to the plant for the repair of railway carriages of freight rolling stock
Students Name: Haba Andrii Orestovych
Qualification Level: magister
Speciality: Electrical Energetics, Electrical Engineering and Electromechanics
Institute: Institute of Power Engineering and Control Systems
Mode of Study: full
Academic Year: 2024-2025 н.р.
Language of Defence: ukrainian
Abstract: The power supply system of the enterprise is a complex consisting of transformer substations, power transmission lines, central distribution points, electricity receivers, consumers of electrical energy, and relay protection and automation devices that ensure the normal operation of electrical equipment by providing it with quality electricity in the required amount. Basic principles of PSS design: - analysis of information about power sources, their distance from the projected facility, passport data of transformers, and installed capacities of consumers; - ensuring reliable power supply while adhering to all quality indicators of electricity and considering the reliability categories of consumers for power supply [5]; - taking into account various types of loads and their locations on the general development plan; - the designed scheme should be easy to read, reliable and of high quality, convenient for maintenance, and comply with all regulatory legal documents; - designing the network with consideration for the future development of the project facility, taking into account potential connections of sub-consumers to the projected power sources; - the designed electrical system must be safe for maintenance personnel, equipped with relay protection devices and automation for disconnecting short-circuit currents and preventing emergency situations at the facility. The subject of the research – electricity supply of a railway freight car repair plant. The object of the research is the selection of the optimal technical and economic variant of the electricity supply system and its modes. The subject of the study is to design the external and internal electricity supply system for the facility, implementing advanced technologies in accordance with current regulatory legal documents. Technical maintenance of cars is a mandatory set of actions aimed at supporting the proper operation of rolling stock. The main criteria for checking the quality of maintenance are efficiency and the condition of the cars. To ensure the constant active use of the wagon fleet and keep it in exemplary working condition, the international technology for car repair is utilized – the ISO 9001-2009 quality standards system. In the section on electrical loads, the calculated electrical load of the repair and mechanical modified statistical method (MSM) for the second (To = 10 min) and third levels (To = 150 min) of electricity supply was determined based on the exact value of the consolidated number of electrical receivers [2]. The calculated electrical loads of other workshops and the plant as a whole were determined using the demand factor method. This section also included a calculation of the load map for determining the center of electrical loads. In the section "Choice of External Electricity Supply Scheme," the number and power of the transformer substations were determined. An optimal cross-section and voltage of the line were selected using an unconditional optimization method. The selected wire was also checked for allowable thermal loads and voltage losses. In the section "Internal Electricity Supply Scheme of the Enterprise," the locations for installing workshop distribution devices were determined, and the number and power of the transformers for workshop transformer substations (CTS) and reactive power compensation units were selected. The configuration of the internal electricity supply scheme was chosen, and the cable lines for the internal electricity supply scheme were selected. The technical and economic comparison of the internal electricity supply scheme variants was conducted using the discounted costs method. This section also included a summary of the reactive power balance. To select and verify the switching devices, a short-circuit current calculation was performed according to DSTU standards [3, 4]. In the section "Steady-State Modes of the Power Supply System," calculations of steady-state normal and emergency modes of the power supply system have been carried out. The main objective of these calculations is to determine the positions of the tap changers and protection devices of the high-voltage transformers and workshop substations, as well as to establish the calculated voltage values at the substations. In certain cases, such calculations can form the basis for special measures to normalize one of the most important indicators of voltage quality – voltage deviation. The selected positions of the tap changers and protection devices of the transformers ensure compliance with the voltage quality standards according to GOST 13109-97 [5]. As a result of this work, a power supply system for the repair of freight train cars has been developed, which is reliable, economically justified, and provides consumers with high-quality electricity in full compliance with current legislation requirements [6]. As a result of the study of the facility: load calculation was performed according to DBN B.2.5-23:2010 [7]; calculation of reactive power compensation devices was performed; the object’s external power supply scheme is selected; short-circuit currents are calculated; the facility’s switchgear equipment is selected; switching devices and cable lines are selected.