The development of electric vehicles has stimulated the semiconductor industry, mainly the development of switching elements for all electric converters. The comparison made in this paper is made from an electrical point of view for different types of semiconductor devices used in the equipment of the electrical system of electric vehicles, such as DC / DC converters, on-board charger, traction inverters. Increasing the autonomy of movement of the vehicle is directly influenced by reducing the energy consumption of the battery and therefore increasing the energy efficiency of these subassemblies by using high-performance semiconductor devices. Although silicon has dominated the world of power semiconductor devices for decades, today new types of composite semiconductors have been used to develop more energy-efficient devices, such as gallium nitride or carbide power transistors. of silicon.
The multiphase motor and multiphase drives, because of their advantages, are used mainly as generators or as the traction system. Multiphase drives have advantages over the conventional three-phase drives, as the reduction of the amplitude and the increasing the frequency of torque pulsation, the reduction of the harmonic currents inside the rotor, the reduction the current per phase and more. The paper presents some applications and considerations for the control of a five-phase inverter, including fault simulation.
The research presented in this paper involves the design of a power control system for a hydrokinetic turbine previously tested in real operating conditions. A maximum power point tracking (MPPT) algorithm was designed and simulated using the required parameters for a specific electric generator. The proposed system consists of a generator connected to the hydrokinetic turbine, a three-phase uncontrolled rectifier, a direct current (DC) boost converter with MPPT control to extract maximum available power, and a buck converter to control the amount of power delivered to the load. In order to test the MPPT algorithm, we built the individual blocks on the basis of the corresponding equations of each component. The algorithm considered the specific parameters of the previously tested turbine as input data and simulated the same water velocities for which the turbine had been tested. Thus, the simulation predicted a power output of 105 W for a water velocity of 1.33 m/s, 60 W for 1 m/s, and 30 W for 0.83 m/s. The efficiency of the control system was demonstrated when the instantaneous power value was maintained at a maximum point, regardless of the rotational speed according to the experimental power curves of the driving rotor obtained for certain water velocities.
Agricultural vehicles, such as tractors, combines, and harvesters, are following the trend of commercial vehicles with a transition from diesel to electric propulsion. Seen as an integrated system, a full-electric tractor is a complex machine with many systems that have to be interconnected for efficient functionality; thus, the need for a central control unit arises. The purpose of this article is to present an electronic control unit that interconnects the powertrain, the hydraulic systems, and the auxiliary systems of a full-electric tractor, with an emphasis on optimization through software design. The article describes the hardware of the electronic control unit and the software state diagrams necessary to implement the functions required by the electric tractor. The results of this article show how, through software optimization, the performances of the tractor can be improved, with parameters such as the response time of the various equipment being a useful indicator of such an improvement. Furthermore, the implementation of trip memory and an easy-to-use human–machine interface allows for easy diagnostic of the electric tractor.
LiDAR sensors are needed for use in vehicular applications, particularly due to their good behavior in low-light environments, as they represent a possible solution for the safety systems of vehicles that have a long braking distance, such as trams. The testing of long-range LiDAR dynamic responses is very important for vehicle applications because of the presence of difficult operation conditions, such as different weather conditions or fake targets between the sensor and the tracked vehicle. The goal of the authors in this paper was to develop an experimental model for indoor testing, using a scaled vehicle that can measure the distances and the speeds relative to a fixed or a moving obstacle. This model, containing a LiDAR sensor, was developed to operate at variable speeds, at which the software functions were validated by repeated tests. Once the software procedures are validated, they can be applied on the full-scale model. The findings of this research include the validation of the frontal distance and relative speed measurement methodology, in addition to the validation of the independence of the measurements to the color of the obstacle and to the ambient light.
The stick–slip phenomenon, the initial stage when the traction wheel starts sliding on the rail, is a critical operation that needs to be detected quickly to control the traction drive. In this study, we have developed an experimental model that uses acceleration sensors mounted on the wheel to evaluate the amplitude of the stick–slip phenomena. These sensors can alert the driver or assist the traction control unit when a stick–slip occurs. We propose a method to reduce the amplitude of the stick–slip phenomenon using special hydraulic dampers and viscous dampers mounted on the tractive axles of the locomotive to prevent slipping during acceleration. This practical solution, validated through numerical simulation, can be readily implemented in railway systems. The paper’s findings can be used to select the necessary sensors and corresponding vibration dampers. By implementing these sliding reducers, a locomotive can significantly improve traction, apply more torque to the wheel, and increase the load of a carrier train, instilling confidence in the efficiency of the proposed solution.