The features of the thermal state of the current collection unit «contact wire -contact insert of the current collector» in the conditions of preparation of electric rolling stock for the journey are considered. As part of the study, a methodology has been developed for estimating the heating temperature of the power sliding contact zone in the conditions of train preparation for journey. Application of the method will help to reduce the number of «burnouts» of the contact wire due to the exact selection of the heating/cooling time of the train for a certain heating/conditioning current when preparing the electric rolling stock for the journey.It was established that the cause of the «burns» of the contact wire in the parking lots when preparing the train dispatch is the excess of the permissible temperature of the power sliding contact as a result of the prolonged action of the heating/conditioning current. The standard approach for determining the duration of heating is based on the average values of the loads on the system and therefore does not take into account some factors, for example, the state of the contact wire, the state of the contact insert of the current collector, the number of cars in the train, and so on. The proposed technique is based on the classical theory of electrical contact and the theory of heating a homogeneous body, which makes it possible to accurately assess the thermal state of the power sliding contact and convenient enough for use in operating conditions.The results of the work are of practical value, since the technology of preparing a train for dispatch can be supplemented by calculating the contact temperature «contact wire elementcontact insert element» in accordance with the proposed methodology. This will allow for a specific train in specific conditions to apply a set of measures to prevent «burnout» of the contact wire in the event of a possible temperature exceeding the permissible value.
The paper presents the results of bench tests of wear resistance of contact inserts of current collector runners made of «ROMANIT-UVLSh» material and their effect on the wear of the copper contact wire is evaluated. This material is a composite with a high content of electrically conductive lubricants capable of forming a thin conductive transition layer in a friction pair. Low temperature in the contact zone, indirectly, indicates a low transition resistance and high energy performance of the sliding contact, and low wear of the contact wire confirms its high tribological and mechanical properties. The use of contact inserts runner's current collectors made from this material is possible, both in alternating and direct current and can provide higher technical and economic indicators in comparison with traditional materials.
Purpose. The purpose of this work is the formation of conceptual approaches to the construction of an effective integrated system of simultaneous synchronized control of the movement and suspension of a maglev vehicle – a magnetoplane. Methodology. The paper uses a technique for simultaneous control of the movement and suspension of a maglev vehicle with the mutually coordinated application of both levitation methods, electromagnetic and electrodynamic, through individual control of the energy supply of each track coil. Findings. The conceptual control principles of a traction-levitation system in a hybrid mode of its operation are substantiated. The interaction of a track structure with a vehicle on an electrodynamic suspension with a linear drive is disclosed and the features of the implementation of the power unit are highlighted. Originality. It is shown that a significant improvement in maglev technology can be achieved due to the mutually coordinated combination of electromagnetic and electrodynamic methods of magnetic levitation and the use of a fundamentally different architecture for constructing a MAGLEV track. It is constructed not from long sections with three-phase power windings, but from discrete ones, they are also linear engine traction coils, and a component (load) of a solar track power plant located along the overpass. The power plant includes a photovoltaic module (solar battery) that converts solar energy into electricity, a storage device and an inverter. This construction makes possible independent supply of each travel coil and its autonomous control with the ability to switch to traction or levitation mode. The control concept is that each track coil can participate both in the creation of a static suspension due to the interaction of the magnetic field of the onboard superconducting magnet and the magnetic field of the track coils when a certain amount of direct current is applied to them, as well as the dynamic suspension provided during the train movement as a result of the interaction of the magnetic field of the onboard superconducting magnet and the magnetic fields created in the track coils by currents induced in them when the magnetic fields of the onboard superconducting magnet intersect. Practical value. The results are of practical value, as the use of such complex control system of the suspension and the magnetic plane movement will significantly improve the quality of MAGLEV technology, increase the efficiency and reliability of high-speed land transport based on electrodynamics levitation using superconducting magnets.
Purpose. The main purpose of our work is to develop a method of rational control of dynamic operation modes of electrochemical energy storage devices to increase the efficiency of their operation as part of the energy supply systems of vehicles. Methodology. The authors reviewed the world literature on the topic of the work. The existing control methods of electrochemical energy storage devices were systematized and classified. Peculiarities and possibilities of their application taking into account the specifics of operation on vehicles, which are characterized by dynamic modes with unpredictable changes in the energy balance due to uncontrolled undercharges and overcharges were taken into account. The analysis of existing control methods showed that their common disadvantage is the use as information parameters to control and manage the operation modes of storage device, such as voltage and operating current, the values of which do not correspond to the current energy state of the device due to the fleeting nature of transient electrochemical processes in the device during operation in dynamic modes. The conclusion is made about the need to take into account the energy parameters of storage devices in the process of managing dynamic modes, which most fully and objectively reflect their performance. The advantage of pulse control methods of storage devices in dynamic modes of operation over DC methods is shown. Findings. The authors substantiated and experimentally confirmed the versatility of the developed galvanostatic method, which allows simultaneous control of the current energy state of the storage device and operational management of dynamic modes of its operation using a common criterion of control and management – the utilization factor of active materials, the information equivalent of which is the value of the area under the depolarization curve on the response signal of the device to the test pulse. Originality. For the first time it is proposed to combine the functions of control of the current energy state of the storage device and operational management of the dynamic modes of its operation with the use of the utilization factor of active materials. Practical value. The obtained results can be used to ensure the optimal operation mode of energy storage in the power supply systems of vehicles.
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