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Li-ion batteries determine the lifespan of an electric vehicle. High power and energy density and extensive service time are crucial parameters in EV batteries. In terms of safe and effective usage, a precise cell model and SoC estimation algorithm are indispensable. To provide an accurate SoC estimation, a current- and temperature-dependent SoC estimation algorithm is proposed in this paper. The proposed SoC estimation algorithm and equivalent circuit model (ECM) of the cells include current and temperature effects to reflect real battery behavior and provide an accurate SoC estimation. For including current and temperature effects in the cell model, lookup tables have been used for each parameter of the model. Based on the proposed ECM, the unscented Kalman filter (UKF) approach is utilized for estimating SoC since this approach is satisfactory for nonlinear systems such as lithium-ion batteries. The experimental results reveal that the proposed approach provides superior accuracy when compared to conventional methods and it is promising in terms of meeting electric vehicle requirements. [ABSTRACT FROM AUTHOR]

In this study, an electric vehicle (EV) dynamic model is devised that amalgamates mechanical design aspects—such as aerodynamic effects, tire friction, and vehicle frontal area—with crucial components of the electrical infrastructure, including the electric motor, power converters, and battery systems. Verification of the model is executed through a comprehensive multidisciplinary analysis utilizing CATIA, ANSYS Electromagnetics, ANSYS Fluent, and MATLAB–Simulink tools, which are applied to evaluate two alternative lightweight EV prototypes. The process involves initial computations of critical inputs for the dynamic model, including aerodynamic lift (C1), drag coefficients (Cd), and frontal area (Af). Subsequent stages entail the detailed design and analysis of a 2 kW brushless permanent magnet electric motor in ANSYS Electromagnetics to map efficiency contours across various speed–torque values. Integration of these parameters into a MATLAB–Simulink dynamic model, connected with motor drive inverter and battery models, allows for simulation-based energy consumption analysis under race track slope profiles. Remarkably, the findings underscore the considerable impact of neglected parameters on energy consumption, often exceeding fifty percent of the total. Consequently, an energy-efficient EV prototype is manufactured and rigorously tested under specified drive conditions, affirming the validation of the comprehensive multidisciplinary EV dynamic model. [ABSTRACT FROM AUTHOR]

In this article, a leaf spring insertion to the stator back iron is proposed to reduce vibration and acoustic noise in a switched reluctance machine (SRM). The back iron of the tooth tip is curved out and the material made up of carbon spring steel is placed to dampen the vibration due to radial force. A 6/4 stator/rotor pole SRM is designed and its natural vibration mode frequencies are determined through finite-element analyses. The optimal current waveform is applied to the SRM model using the multidisciplinary coupled simulation method to determine the radial force with the harmonic orders. In the final step, the proposed leaf spring architecture is optimized to achieve the most dampening for the effective radial force harmonic orders. The simulation and experimental results confirmed the effectiveness of the leaf spring insertion in reducing the noise and vibration in SRMs. [ABSTRACT FROM AUTHOR]

Multiphysics analysis and experimental validation of acoustic noise reduction in a high pole count, high power, switched reluctance machine (SRM), through skewing are explored in detail in this work. An iterative optimization strategy covering electromagnetic, structural, and thermal domains is proposed to investigate the effect of different skewing methods and angles on a 24-stator slot/16-rotor pole (24/16) SRM rated at 100 kW. The contributions of this work are twofold. First, electromagnetic impact, considering average torque, torque ripple, radial and tangential air gap forces, of symmetric and asymmetric skewing on stator and rotor is studied in this work. Second, the impact of skewing methods on acoustic noise and vibration performance is studied and presented in detail. The study reveals that skewing both the stator and rotor by the same amount has superior electromagnetic performance over other types of skewing. Multiphysics simulations conducted, predict a 10.5 dBA reduction in the acoustic noise, compared to a baseline design with no skew, for an optimized rotor-stator skewing angle of 13.75°. Finally, 100 kW prototypes of the baseline and the optimized skewed SRM were constructed and subjected to wide speed range testing. Simulation and test results closely follow each other and validate the effectiveness of the proposed skew design in mitigating acoustic noise and vibration in high pole count SRMs. [ABSTRACT FROM AUTHOR]

Switched reluctance machines (SRMs) have been studied by many researchers as an alternative to the other types of electrical machines for use in electric and hybrid vehicle applications. SRMs are fault tolerant and have wide speed operating range. However, they suffer from several disadvantages, including high vibration, acoustic noise, and torque ripple. In this article, the placement of rectangular windows in both the rotor and stator poles is proposed to reduce the vibration and acoustic noise of SRMs. An iterative optimization algorithm in a wide speed range of operation using finite-element analysis (FEA) tools provides the best position and dimension of window design parameters. Multiphysics FEA is also performed to predict the vibration and acoustic noise of the optimized design. The results of this study present that placing windows in both the stator and rotor of the SRMs can significantly reduce the acoustic noise compared with the baseline SRMs. Based on the simulation results, the optimum design has been constructed as a prototype and tested in a wide speed operating condition. The simulation and experimental test validation results prove the effectiveness of the proposed design in mitigating the acoustic noise and vibration. [ABSTRACT FROM AUTHOR]

In this paper, power losses in high-speed switched reluctance machine (HS-SRM) is studied considering the copper loss, including skin and proximity effect, iron loss in machine side; switching and conduction losses in the drive circuit side using interactive coupled simulation methods. In high frequency fed electric machines, copper losses are increased due to the skin and proximity effects. Moreover, iron losses play a significant role in total electrical losses. Nevertheless, its computation is not straight. In addition, power electronics switching devices cause both conduction and switching losses in the SRM drive circuit. Switching loss may reach excessive levels with the high-frequency switching. In this study, the losses are calculated detailed though coupled simulation method. Different wire constructions in the bundle are analyzed and compared. Finally, circuit simulation is performed on different switching devices. The results prove that high-speed switched reluctance machine driving and operating efficiency is really sensible to design methodology with suitable material and device selection. [ABSTRACT FROM AUTHOR]

This paper investigates the operating modes and converter options of dual winding permanent magnet synchronous machines (DWPMSMs) that are used to drive accessories in hybrid electric vehicles. In this application, DWPMSM operate in three different modes: 1) motor-only; 2) generator-only; and 3) simultaneous motor–generator modes. Motor-only and generator-only operations can be treated independently as long as two winding sets are magnetically decoupled. Simultaneous motor–generator mode links two winding sets through a mechanical shaft. As part of this study, the impact of dual winding set usage on the machine's output and performance is also investigated. Experimental results are given for each mode. The converter options of generator winding were investigated as well. These options include uncontrolled rectifier with dc–dc converter and controlled rectifier. Two converters are compared for their impacts on efficiency and generator current harmonics. The relationship between speed and converter control variable is given for various back electromotive force constant values of the DWPMSM. [ABSTRACT FROM AUTHOR]