Double-action electrodynamic retarder system

An automobile braking system has a crucial role for safety of the passenger and riding quality of the vehicle. The brakingforce mainly depends on the normal reaction on the wheel and the coefficientof adhesion between the tire and the road surface. Sometimes the motorcycle may be over braked (Braking force exceeds the traction capacity between tire and ground) that increases vehicle stopping distance due to wheel sliding. So a variable braking force (VBF) system is developed in whichthe effective brake disc radius is variedbased on the pillion load on the motorcycle, for varying the rear wheel braking force that develops between tire and road surface. Whenever amotorcycleis loaded, the normal reaction on the rear wheel is increased.Thus the amount of braking force required to halt the motorcycle withminimum stopping distance and stability of the motorcycle, is based on the pillion load on the motorcycle. Hencethe amount of braking forcedeveloped between the road surface and the tire is varied in the variable braking force system. In this work, a mathematical modeling is developed and analyzed using MATLAB when the rear brake is applied for a motorcycleduring cornering for conventional disc brake system and the variable braking force system. It is found that variable braking force system develops more amount of yaw rate and lateral displacement when it is compared with conventional disc brake.

Currently, the task of optimizing car maintenance intervals for various operating conditions is urgent. To do this, it is necessary to conduct research to justify the frequency of car maintenance through mileage or time interval. At the same time, the service intervals (period, mileage) may differ for different elements of the car. The use of modern diagnostic tools (external and built-in) allows you to assess the technical condition of units, components and operational materials and perform routine maintenance, in particular, oil change, according to the actual condition, and not by mileage or time interval. This helps to increase the resource of aggregates and save financial resources by optimizing the maintenance interval of cars. In this paper, the authors analyzed car maintenance systems in Russia and abroad, in particular, the frequency of oil change of passenger car engines in Europe, Asia and the USA. The features of the operation of vehicles in difficult and difficult conditions, including in mountainous terrain, are considered. The analysis of the main factors affecting the quality of engine oil and, accordingly, the frequency of oil change is given. In the article, based on the conducted research and analysis of the issue, recommendations have been developed for replacing oil in car engines according to its condition for various conditions of the Republic of Dagestan (RD). The use of external and built-in diagnostic tools to assess oil quality allows you to calculate the recommended engine oil replacement interval. As a result of the conducted research on a certain number of cars, recommendations have been developed to determine the optimal engine oil replacement period for various operating conditions in the region.

Powertrain development in the automotive industry has changed significantly over the recent years and is forecasted to alter even more in the near future. For many decades, the internal combustion engine was the only propulsion system for passenger cars and commercial vehicles. The need to minimize CO2 emissions from the transportation sector to limit global warming as well as the new requirements to reduce real driving emissions (RDE) to further improve air quality, specifically in urban areas, forced OEMs, Tier1 suppliers and engineering service suppliers to also develop electrified powertrains. The portfolio of vehicle propulsion systems in the future will include pure electric vehicles, full (plug-in) hybrid vehicles, mild electrified (48V) hybrid powertrains but also vehicles still only using conventional combustion engines. This enlarged variety in powertrain configurations requires enormous engineering efforts in the development and testing of the full bandwidth of powertrains. To allow a parallel development of the different technologies, it is essential to keep the costs of calibration and testing to a minimum in order to ensure affordable products. To achieve this, a synthesis of advanced simulation methods and modern testing equipment is the suitable solution. It generates a variety of new test procedures and methods for the efficient development of complex propulsion system architectures. The Institute for Combustion Engines at the RWTH Aachen University presented a method to couple a conventional internal combustion engine installed in one test cell via a virtual shaft with an electric machine and / or a transmission installed on another test bench. [1] Another approach is to virtualize individual elements or sub-systems of the powertrain and the environment around the test object. In this case, physical components of the powertrain (e.g. engine, transmission, electric machine) or control units will be connected to virtual systems / components (e.g. vehicle, hybrid powertrain, environment, etc.). [2] This allows the calibration of the full target system while only one part / component is physically available and operated on a test bench. The FEV Group has defined and implemented a consistent strategy for virtual calibration using multiple X-in-the-Loop systems and integrated this approach into the established, quality-guided standard calibration process. Representative examples of characteristic use cases are presented in this paper and the pertaining challenges and benefits are described in more detail.

This paper reports on an experimental investigation into braking-related steering drift in motor vehicles, and follows on from a previous paper by the authors in which it was concluded that braking can cause changes in wheel alignment that in turn affect the toe-steer characteristics of each wheel and therefore the straight-line stability of the vehicle during braking. Changes in suspension geometry during braking, their magnitude and the relationships between the braking forces and the suspension geometry and compliance are further investigated in an experimental study of wheel movement arising from compliance in the front suspension and the steering system of a passenger car during braking. Using a kinematic and compliance (K&C) test rig, movement of the front wheels and the suspension subframe, together with corresponding changes in suspension and steering geometry under simulated braking conditions, have been measured and compared with dynamic measurements of the centre points of the front wheels. The results have enabled the causes and effects of steering drift during braking to be better understood in the design of front suspension systems for vehicle stability during braking.

In spite of the many significant improvements in car chassis design over the past two decades, steering drift during braking where the driver must apply a corrective steering torque in order to maintain course can still be experienced under certain conditions while driving. In the past, such drift, or ‘pull’, would have been attributed to side-to-side braking torque variation [1], but modern automotive friction brakes and friction materials are now able to provide braking torque with such high levels of consistency that side-to-side braking torque variation is no longer regarded as a cause of steering drift during braking. Consequently, other influences must be considered. This paper is the first of two papers to report on an experimental investigation into braking-related steering drift in motor vehicles. Parameters that might influence steering drift during braking include suspension compliance and steering offset, and these have been investigated to establish the sensitivity of steering drift to such parameters. The results indicate how wheel movement arising from compliance in the front suspension and steering system of a passenger car during braking can be responsible for steering drift during braking. Braking causes changes in wheel alignment which in turn affect the toe steer characteristics of each wheel and therefore the straight-line stability during braking. It is concluded that a robust design of suspension is possible in which side-to-side variation in toe steer is not affected by changes in suspension geometry during braking, and that the magnitude of these changes and the relationships between the braking forces and the suspension geometry and compliance require further investigation, which will be presented in the second paper of the two.

Rolling element bearings are very important components in electrical machines. Almost 50% of the faults that occur in the electrical machines occur in the bearings. This makes bearings as one of the most critical components in electrical machinery. Bearing fault diagnosis has drawn the attention of many researchers. Generally, vibration signals from the machine’s accelerometer are used for the diagnosis of bearing faults. In literature, application of Deep Learning algorithms on these vibration signals has resulted in the fault detection accuracy that is close to 100%. Although, fault detection using vibration signals from the machine is ideal but measurement of vibration signals requires an additional sensor, which is absent in many machines, especially low voltage machines as it significantly adds to its cost. Alternatively, bearing fault diagnosis with the help of the stator current or Motor Current Signal (MCS) is also gaining popularity. This paper uses MCS for the diagnosis of bearing inner raceway and outer raceway fault. Diagnosis using MCS is difficult as the fault signatures are buried beneath the noise in the current signal. Hence, signal-processing techniques are employed for the extraction of the fault features. The paper uses the Paderborn University damaged bearing dataset, which contains stator current data from healthy, real damaged inner raceway, and real damaged outer raceway bearings with different fault severity. Fault features are extracted from MCS by first filtering out the redundant frequencies from the signal and then extracting eight features from the filtered signal, which include three features from time domain and five features from time–frequency domain by using the Wavelet Packet Decomposition (WPD). After the extraction of these eight features, the well-known Deep Learning algorithm Long Short-Term Memory (LSTM) is used for bearing fault classification. The Deep Learning LSTM algorithm is mostly used in speech recognition due to its time coherence, but in this paper, the ability of LSTM is also demonstrated with the fault classification accuracy of 97%. A comparison of the proposed algorithm is done with the traditional Machine Learning techniques, and it is shown that the proposed methodology outperforms all the traditional algorithms which are used for the classification of bearing faults using MCS. The method developed is independent of the speed and the loading conditions.

This paper describes the magnetic properties of different permanent magnet materials and their industrial usage as crucial components of permanent magnet electric machines. As the prices of rare earth materials, especially neodymium-iron-boron (NdFeB), has been rising rapidly during the last few years and has been quite unstable during the past decade, the search of new cheaper and yet durable alloys has started. One of the possibilities of cutting the price of NdFeB alloys is the decreasing of the dysprosium (Dy) content of such material. Possibilities of using these new materials in electrical machines as well as potential risks are analyzed in the paper. An overview of the development of low Dy magnets is presented. Necessity of further investigations is pointed out.

A vital component of electrical machines (EMs), which plays the most significant role in their reliable and proper operation, is their insulation system. Synchronous generators (SGs) are the most commonly used EMs in energy production and industry. Epoxy resin and mica are the predominant insulation materials for the SGs’ windings because their characteristics and properties are suitable for extending the lifetime of the insulation. Partial discharges (PDs) are both a symptom of insulation degradation, as they cause serious problems for insulation, and a means to identify possible insulation faults with offline and/or online PD tests and measurements. A comparison of three different equivalent circuit models of PDs occurring in different insulation materials (epoxy resin, mica, and a combination of these two) is presented in this paper. Different applied voltages and/or various geometries of voids are the factors investigated through simulations. The number of PDs, PD activity, and flashover voltages are examined in order to evaluate which of the aforementioned materials has the best reaction against PD activity.

The use of advanced computational methods: finite-element analysis (FEA) and computational fluid dynamics (CFD) will be considered in this chapter. FEA is useful to model conduction heat transfer, while CFD can additionally model fluid flow. Both methods rely on modelling the actual geometry of the full machine or machine component by discretizing the individual parts into smaller mesh elements, volumes or cells over which the heat transfer or flow variables are assumed constant. Triangular and quadrilateral mesh element shapes are typically used for 2D geometries, and tetrahedral, quadrilateral pyramid, triangular prism, and hexahedral shaped cells for 3D geometries.The FEA method is often applied to individual components in the electrical machine where the heat transfer mode is by conduction, such as the slot and winding. Useful models can often be formed in 2D. 3D FEA models for a particular part can also be created but are less commonly used due to the additional time to set up and solve.CFD is mainly of use to model the fluid flow and convection from surfaces in the machine and the models are nearly always 3D in nature. Models can be created for individual components of the machine or for the full machine, although this can be very complex to put together and solve. The model may also include conduction heat transfer.

Electrodynamic levitation effect in vertical HTSC electrical machines with

The armed aggression of the Russian Federation against Ukraine led to the destruction of critical infrastructure, the termination of port operations in Ukraine, the disruption of regional logistics, the rise in fuel prices, and the increase in ship and cargo insurance costs. It contributed to the restriction of trade in the Black Sea region. The armed aggression of the Russian Federation against Ukraine hinders trade and changes logistics in and throughout the Black Sea region. As a result, the search for alternative trade routes for Ukrainian goods quickly increased the demands on land and sea transport infrastructure and services. The work aims to identify trends in developing the main segments of the Ukrainian sea freight transportation market in current business conditions. To solve the tasks, the following methods were used: comparative analysis and grouping - in the study of general trends of the Ukrainian sea freight transportation market; systemic structural analysis - when studying the state and determining the prospects of tanker, container, and dry cargo transportation in Ukraine. An analysis of the general trends of the Ukrainian sea freight transport market was carried out. In addition, the state and prospects of tanker, container, and dry cargo transportation in Ukraine have been studied in detail. The tanker transportation sector was the most affected. Tanker transportation in Ukraine was suspended. Shipping companies engaged in the transportation of containers have stopped work in Ukrainian seaports. At the same time, a slight increase in the volume of container transportation was observed in the ports of countries bordering Ukraine. The complete blockade of Ukrainian seaports and the destruction and damage of infrastructure facilities made it impossible for dry cargo ships to reach Ukrainian ports. With Ukrainian seaports blocked and port operations suspended, grain exports from Ukraine were limited to shipments through western borders, rail, and small ports. The issue was partially resolved only within the framework of signing documents regarding the implementation of the Initiative on the safe transportation of agricultural products from three Ukrainian ports. The article outlines the critical factors in developing the maritime cargo transportation market in Ukraine during the post-war period of economic development.

The progress in improvement of the electrical, thermal, and mechanical properties of composite materials opens new possibilities for replacing metal components in constructing electrical machines. Owing to low density of the majority of these materials in comparison with conventional materials, it becomes possible to decrease the specific weight and achieve better processability due to minimal machining and the possibility of making parts having the finished shape. Studies of using composite materials in individual units of electrical machines show the possibility of minimizing material intensity, increasing energy density, and achieving better energy efficiency. One of possible ways to increase energy density and energy efficiency is to construct high-speed electrical machines that are able to generate maximum power with the minimum amount of active and structural materials. The characteristics of electrical machines are determined by losses, which in turn depend on the electromagnetic and thermal properties of the applied materials. In this respect, composite materials differ favorably from conventional materials. Thus, composite materials consist of plastic bases reinforced with fillers. By combining dissimilar materials, a new material is obtained, the properties of which may differ significantly from the properties of its individual components. The results from a comparative analysis carried out for three designs of electrical machines with different contents of composite materials are presented. Full electromagnetic and thermal analyses of these designs carried out using the finite element methods are given, their specific characteristics are determined, and their efficiencies are estimated. It has been found that the weight of an electrical machine that consists completely of composite materials is by 73% smaller than that of an electrical machine made of conventional materials. The efficiency of an electrical machine made fully of composite materials is 92%, a conclusion that confirms good prospects of applying composite materials in electrical machine components. The thermal analysis results confirm that an electrical machine made completely of composite materials will have full operability.

Pulsed electrical machines such as the compensated pulsed alternator (compulsator) are increasingly being considered for mobile applications. Size and weight reduction in these machines is therefore very important. Composite materials, such as carbon fiber and glass fiber epoxy composites, with high strength and low density are a natural choice for the various structural components of these electrical machines. The carbon fiber-epoxy composite (CFC) is particularly useful because of its high strength and modulus. However, this composite (CFC) is electrically conductive with greatly different electrical conductivities along the fibers and transverse to the fibers. When these materials are used in pulsed machines, it is important that the designer be cognizant of the conductivity and treat the anisotropy adequately. This paper illustrates how the eddy current distribution can be determined in carbon fiber composites in light of the anisotropy.

Against the background of system integration, the increase of energy efficiency and device mobility it is worthwhile to investigate alternative production methods for electrical machines. In this paper 3D Screen Printing as a new technology for producing components of electrical machines or even whole motors is introduced. Therewith revolutionary materials and machine designs are suitable. The resulting effects because of a new machine design are higher rated temperature, improved efficiency and higher torque density.

<div class="section abstract"><div class="htmlview paragraph">Presently, the automotive industry is being renovated with the help of an electrical machine, batteries, and power electronic components. In this technological shift, permanent magnet machines (PMSM) are mainly preferred for traction, because of their high efficiency and power density. The noise, vibration, and harshness (NVH) performance of the electrical machine is one of the main challenges, due to the tangential and radial electromagnetic forces. In this research study, a geometrical and electrical approach has been executed to reduce the radial force, which has a larger impact on vibration and noise. Initially, a permanent magnet synchronous motor with a V-shaped magnet configuration has been designed and the output performances are analyzed. The base structure (V-shaped magnet without duct) highlights that the radial force in the 12/3 and 12/12 order is higher, which will increase the vibration and noise of the motor. In this proposed geometrical approach, a duct has been introduced in the rotor outer periphery, which will reduce the airgap permeance and minimize the radial force. Different duct-shaped rotor configuration has been simulated using finite element analysis. The effectiveness of different duct shapes (like circle, rectangle, and ellipse) is analyzed and compared. The radial electromagnetic forces of a motor without duct and with duct have been provided. After placing the duct, the radial force was reduced which minimizes the vibration and noise. The ellipse duct rotor configuration shows better electromagnetic performance compared with rectangle and circle-shaped ducts. An electrical approach has been proposed to minimize the radial electromagnetic forces by injecting harmonic current and current angle on <i>d-</i>axis and <i>q-</i>axis. Finite element analysis with various results ensures the improved structure with an ellipse-shaped duct can reduce the radial force of the motor by around 36%.</div></div>