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This article presents an efficiency optimization of double-sided LCC compensation network for inductive power transfer systems. Compensation factors of the primary and secondary LCC circuit are defined and optimized analytically. The investigation shows that the secondary compensation factor $k_{rx}$ highly influences the copper loss of the wireless coupler, whereas the primary compensation factor $k_{tx}$ should not be large in order to reduce the switching loss and conduction loss of the input inverter. With a proper selection of these compensation factors, it is possible to achieve a high and sustained efficiency over a wide range of load and misalignment. In order to demonstrate the feasibility and validity of the proposed method, a scaled-down prototype has been implemented with the operating frequency of 85 kHz, transfer gap of 170 mm, and misalignment of up to 100 mm. Experimental results show a good agreement with the theoretical analysis. The peak efficiency of the proposed system is 91.6% under the perfect alignment at the coupling coefficient of 0.172. The efficiency still remains at 86.37% even under 100-mm misalignment with the coupling coefficient of 0.123. [ABSTRACT FROM AUTHOR]

In this article, a simplified 3D magneto-thermal model to study the temperature distribution over the housing of a Switched Reluctance Machine (SRM) is proposed. The main objective of such model is to study the temperature distribution profile on the body of the machine under various working conditions in order to introduce a temperature based signature to develop condition monitoring procedures. The analysis of fluid flow and heat transfer inside the SRM supports the hypothesis that the effect of turbulent flow of the fluid and the complex heat transfer phenomenon of the rotating parts can be simplified to a heat flux boundary condition representation of the heat loss. The accuracy of the model is validated through simulation and experimental results on a prototype SRM. The developed simplified model can be used as for prediction of temperature profile on SRM surface, well suited for fault diagnosis in SRM. The proposed methodology can be modified applied in developing a thermal model for other types of electric machines. [ABSTRACT FROM AUTHOR]

With the development of high-temperature wide bandgap power semiconductors, such as SiC MOSFET and GaN HEMT, it becomes possible to integrate the power converter directly into motors. However, the leakage magnetic flux in the motor may cause interference with the operation of the electronic circuit. In this article, the electromagnetic compatibility of the power converter integrated in an induction motor is investigated. The simulation shows that the leakage magnetic flux of the end-winding will penetrate into the nearby area, and it will cause interference with the Hall-effect current sensors if the power converter is mounted in the space between the motor end cap and the end-winding. A prototype of the GaN-HEMT-based power converter is built and integrated into a 3-hp induction motor. The leakage magnetic flux is scanned by the linear Hall-effect sensors and the measured result is aligned with the finite-element simulation. [ABSTRACT FROM AUTHOR]

Vibration and acoustic noise are considered as major factors preventing the widespread use of switched reluctance motor (SRM) drives in industrial and commercial applications. In this paper, a new active vibration cancellation strategy for radial vibration is proposed based on the optimal current switching instants. The mechanical impulse response method has been used to estimate the radial vibration of the stator and an optimization routine was developed to define the optimal instants for phase current switching in such a way that the resulting vibration would cancel the vibration caused by prior switching. Experimental verification was conducted on an 8/6 SRM and the results show significant reduction in the stator radial vibration which in turn contributes to reduction of acoustic noise. [ABSTRACT FROM AUTHOR]

Vibration and acoustic noise in switched reluctance motor (SRM) drives have been investigated and addressed frequently. However, the focus of most the paper is on vibration of the stator frame due to radial electromagnetic forces acting on the stator teeth. In this paper, a comprehensive vibration analysis for a SRM assembly using finite element (FE) method is conducted, which considers the stator and rotor vibrations due to radial electromagnetic force as well as the effect of mechanical coupling on the vibration between the stator and rotor. First, an experimental modal test was performed to extract modal parameters and to observe the coupling effect. The parameters were then used to adjust and validate the FE model that was used to obtain transfer functions for vibration characterization. Using the frequency domain representation of the radial magnetic force vector and the calculated transfer functions, radial and tangential vibration components have been predicted. [ABSTRACT FROM AUTHOR]

The performance of lithium-ion batteries is contingent on the operational temperature and applied current rate. Especially in electric vehicle application, repeated heavy-duty drive cycles impose intense thermal stress on batteries, resulting in safety concerns. This paper explains the electrochemistry within the battery and analyzes the dependence of battery internal parameters on temperature and current rate based on their electrochemical nature. In addition, this interdependence is used in the equivalent circuit model to predict the battery behavior under different drive cycles. Finally, the behavior under different drive cycles is analyzed to improve the battery performance in electric vehicles. [ABSTRACT FROM AUTHOR]