Three-phase power transformer modelling in AC/DC traction substations

Three-phase power transformer is one of the most important elements in the electric power systems, and it plays a significant role in terms of energy savings. Since the efficiency standards can be expressed in terms of electrical efficiency, in an attempt to improve the transformer efficiency, in this study an enhancement of three-phase power transformer modelling with space phasors is presented. There are established the equations with space phasors of the three-phase transformer with symmetrical compact core. This equations system can be used to analyze the dynamic regimes of three-phase transformers. In this paper have been analyzed some aspects of three-phase power transformer operation in a AC/DC traction substation

Utilizing the Exergy Concept to Address Environmental Challenges of Electric Systems

entrop

Approaching Resonant Absorption of Environmental Xenobiotics Harmonic Oscillation by Linear Structures

sustainabilit

Operation analysis of AC traction motors in terms of electromagnetic torque capability on sustainable railway vehicles

Sustainable operation of electric railway systems represents a significant purpose nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. An important issue that correlates these aspects is the electromagnetic torque developed by an electric traction motor. In order to provide an overview of the technical performance of the operation of sustainable railway systems, a detailed analysis is carried out of the electromagnetic torque capability of AC electric motors utilized as traction motors in modern locomotives of high power and/or high speed. The results of this work may help in enhancing the main criteria for optimising the safe and sustainable operation of electric railway traction systems

Approaching the Processes in the Generator Circuit Breaker at Disconnection through Sustainability Concepts

sustainabilit

Operation analysis of AC traction motors in terms of electromagnetic torque capability on sustainable railway vehicles

Sustainable operation of electric railway systems represents a significant purpose nowadays in the development of high power and high speed locomotives and trains. At present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors. The two electric machine types have different efficiencies at different operation points, and experience differences with respect to safety, speed and power, energy use and exergy efficiency. An important issue that correlates these aspects is the electromagnetic torque developed by an electric traction motor. In order to provide an overview of the technical performance of the operation of sustainable railway systems, a detailed analysis is carried out of the electromagnetic torque capability of AC electric motors utilized as traction motors in modern locomotives of high power and/or high speed. The results of this work may help in enhancing the main criteria for optimising the safe and sustainable operation of electric railway traction systems

Evaluating through mathematical modelling the power equipment busbars electrodynamic strength under sudden short-circuit conditions

The electrodynamic strength, as forces acting between the current-carrying electric circuits are exerted as long as the currents exist, and have the tendency of deformation and displacement of the circuits. In short-circuit regimes the strength in electrical equipment becomes severe. For instance, short-circuits highly affect power transformers connected to power transmission lines. The effects are also strong because of mechanical deformations occurring in the power transformer connection part. In line with this idea, in this paper it is made an analytical study upon the a.c. single-phase and a.c. three-phase electric circuits, taking into account the current instantaneous maximum value. The paper also entails numerical simulations of electrodynamic strength in power transformer busbars under short-circuit conditions. MATLAB software, with its specific extensions, enable simulation models to generate the charts of the electrodynamic forces in the power transformer connection bars

Evaluating through mathematical modelling the power equipment busbars electrodynamic strength under sudden short-circuit conditions

International audienceThe electrodynamic strengths, as forces acting between the current-carrying electric circuits are wielded as long as the currents exist, and have the tendency of deformation and displacement of the circuits. In short-circuit regimes the strength in electrical equipment becomes severe. For instance, short-circuits highly affect power transformers connected to power transmission lines. The effects are also strong because of mechanical deformations occurring in the power transformer connection part. In line with this idea, in this paper it is made an analytical study upon the a.c. single-phase and a.c. three-phase electric circuits, taking into account the current instantaneous maximum value. The paper also entails numerical simulations of electrodynamic strength in power transformer busbars under short-circuit conditions. MATLAB software, with its specific extensions, enable simulation models to generate the charts of the electrodynamic forces in the power transformer connection bars

Evaluating the Thermal Pollution Caused by Wastewaters Discharged from a Chain of Coal-Fired Power Plants along a River

Reliable and safe operation of a coal-fired power plant is strongly linked to freshwater resources, and environmental problems related to water sources and wastewater discharge are challenges for power station operation. In this study, an evaluation on the basis of a wastewater thermal pollution vector is reported for the environmental impact of residual water generated and discharged in the Jiu River during the operation of thermoelectric units of the Rovinari, Turceni and Craiova coal-fired power plants in Romania. Wastewater thermal pollutant vector Plane Projection is applied for assessing the water temperature evolution in the water flow lane created downstream of each power plant wastewater outlet channel. Simulation on the basis of an Electricity of France model, and testing validation of the results for thermoelectric units of 330 MW of these power plants are presented