Purpose. Investigation of the influence of sharply variable electric load on non-stationary electromagnetic phenomena and electromechanical processes in a synchronous electric drive. Methodology. ...Theoretical and experimental methods of research and analysis of a set of parameters of sharply varying loads of electrotechnological complexes and electromagnetic processes in electrical equipment; physical and analytical methods for obtaining dependencies of the influence of electrotechnical loads on the technical condition, the breakdown of electrical equipment, additional losses and non-stationary electromagnetic phenomena in systems and equipment. Findings. The calculations of the excess of the oscillatory processes of the synchronous electric drive shaft are performed, which are excited by sharply varying loads, relative to the norms standardized by state standards. Proceeding from the primary requirements of the electric drive and providing normalized oscillations of the motor shaft and increasing requirements to reliability, efficiency and energy consumption per unit of output, the effect of non-stationary electromagnetic processes on the electromechanical parameters of the electric drive was investigated. Originality. A mathematical technique is proposed for non-stationary electromagnetic processes in a synchronous electric drive, which allows one to investigate the effect of non-sinusoidal and unbalanced currents and voltages on electromechanical parameters. An engineering technique for estimating the oscillatory function of a shaft is given, depending on the nature of non-stationary electromagnetic processes in a synchronous motor. Practical value. An engineering technique for estimating the oscillations of a synchronous electric drive shaft is proposed for non-stationary electromagnetic processes, which lead to an increase in the parameters of normative and technical documentation.
This paper presents the design of a high-performance liquid-cooled heatsink for three-phase automotive inverters that attains uniform thermal distribution at the surface of the three power modules. ...Power modules with SiC-MOSFETs are used in this study and a uniform thermal distribution on the heatsink guarantees equal thermal loading of the semiconductor devices. A comparative study of various cooling plate geometries is made and their effectiveness in meeting the design objectives of low sink-temperature and coolant pressure drop and the highest possible temperature uniformity along the surface of the plate is presented. Plates with straight and wavy fins are compared with designs accommodating rectangular pins and the advantages of each case is shown with the corresponding simulation results. Key design parameters of the cooling plate geometries are optimized with an iterative process, which is presented with selective simulation results of 3D Conjugate Heat Transfer computations for coolant flow rates up to 10 l/min. The final heatsink design accommodates multiple rectangular pins and attains temperature difference of less than 2 o C among the three SiC power modules.
The article deals with the device in the form of Stewart platform with adaptive, robust control and fuzzy logic control. It ‘describes electric rods. The algorithms and systems of position-force ...control with variable structure are considered. The results of the simulation platform developed by Stewart layout with a crank mechanism are presented.
The schemotechnical solutions of object controllers (OCs) cannot be generally accessible due to their technological value. At the same time, OCs are an integral part of computer-based interlocking ...systems (CBIS), and study of their operation is required to determine the prospects of development and training of the service staff of CBIS.
To replenish the insufficient information, the analysis has been carried out per the description of CBIS EBILOCK 950 and the circuit-based technical solution for high-power outputs of MOT OC for three-phase e-motors of alternating current is offered.
The proposed schemotechnical solution comprises also a set of diagnostic tools (DT). This set enables to follow the technical condition of power elements of MOT OC, as well as the technical condition of the object of control and diagnosing (OCD), which increases the penetration depth of DT.
Application of the expanded set of DT in high-power outputs of MOT OC, allows to ensure more efficient maintenance process of point machine. The maintenance efficiency is achieved through use of technical diagnosis of OCD and determines the maintenance frequency, ensuring the timeliness of preventive work.
The article discusses a mathematical model of a control system for exoskeleton electric drives with nonlinear elements. The development of a exoskeleton dynamic model includes five links with two ...legs and a body, taking into account non-linear electric drives as a control object. Modeling mechanical systems is an important step in the practical design and application of control systems. The nonlinear approach to modeling is due to the use of a control system for the exoskeleton electric drives in various conditions, which is a multi-mass rotating in two directions with nonlinearities of the viscous and Coulomb friction, elasticity. A method of subordinate control (SC) of exoskeleton nonlinear electric drives for tracking control of the exoskeleton joints trajectory is presented. Also, the results of the experiment on the Matlab / Simulink program were obtained to illustrate the effectiveness of the proposed control strategy.
Using the 2009 National Household Transportation Survey (NHTS), an analysis of opportunity charging potential during daytime, for the time interval when a car or SUV is parked for the longest ...duration, is presented here. We focus on charging at 3.3 kW or less, either using the charger at the dwelling unit a second time per day (a one charger solution), or using a second charge point at work. Our earlier research with the 2009 NHTS indicates that nearly 60% of vehicles within this sample were driven to work, or returned to home between 6:00 AM and 6:00 PM. In this analysis we consider the potential for daytime charging before summertime afternoon utility load peaks, anticipating that Public Utility Commissions (PUCs) supporting smart grid pricing strategies may impose much higher electricity costs at these times. We consider kW ratings of typical opportunity chargers versus overnight chargers. We consider the plug-in hybrid with 28 km of urban electric range (PHEV28), the extended range electric vehicle with 56 km of universal all-electric operation capability (EREV56) and the battery electric vehicle with 117 km of electric range (BEV117). Electricity demand and gasoline fueled miles reduction is examined for the average circumstance in two daily distance brackets (48-80 km, 80-160 km) and for two charging behaviors – (1) overnight and (2) both overnight and during the longest duration parking event of daytime hours, from 6 am to 6 pm.
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