Dielectric properties of sunflower, rapeseed and commonly used mineral oil

Ulrych, Jiri; Mentlík, Václav

doi:10.1109/epe.2016.7521753

Cited by 10 publications

(2 citation statements)

References 22 publications

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“…The main causes of EDM currents have been understood and modeling approaches at different system levels have been proposed. This includes, for example, the mineral oil behavior under electric discharges [10], estimation of the capacitance formed by the hydrodynamic lubrication areas of the bearings [11], [12], impedances of full bearings [13]- [15], mechanical models of bearings [16], modeling of the capacitances [17], [18] and equivalent circuits of the assembled system [12], [19], [20]. However, techniques to correctly determine the model parameters are still much needed.…”

Section: A Motivationmentioning

confidence: 99%

Normalization-Based Approach to Electric Motor BVR Related Capacitances Computation

Ahola

Muetze

Niemelä

et al. 2019

IEEE Trans. on Ind. Applicat.

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Electrical discharge machining (EDM) bearing currents that may occur within electric machines of variablespeed-drive motor systems have been recognized for a long time.One key influential factor, the machine's capacitive voltage divider "bearing-voltage-ratio" BVR strongly depends on the rotor-to-frame and the stator winding-to-rotor capacitances; these are, in turn, affected by the design of the machine's stator slot. This paper presents an approach to improve the accuracy with which these capacitances can be estimated. It is based on the well-known plate capacitance equation which is then corrected by normalization functions. The functions are defined by extensive parameter studies using electrostatic FEM simulations. The final expressions not only allow for the prediction of the statorwinding-to-rotor and rotor-to-frame capacitances, they are also readily applicable. Thereby, they facilitate, for example, the clear-cut study of the sensitivity of the BVR towards changes in the different stator slot parameters.

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Section: A Motivationmentioning

confidence: 99%

Normalization-Based Approach to Electric Motor BVR Related Capacitances Computation

Ahola

Muetze

Niemelä

et al. 2019

IEEE Trans. on Ind. Applicat.

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“…In order to circumvent this problem, in [16] rapeseeds were ground and then measured in a fixture equipped with an open-ended probe in the frequency range from 10 MHz to 3 GHz at temperatures from 20 to 60 • C. Paper [11] presents the dielectric characterization of rapeseeds also in powder form at 8.93 GHz at various packing fractions at room temperature. The dielectric properties of rapeseed oil were also measured at various radio and microwave frequencies [17,18]. In [19], ε * of whole seeds was measured at 5-30 MHz in 30-80 • C temperature range with the use of an LCR meter and an Agilent dielectric test fixture which was a parallel-plate capacitor configured for 16.4 mL of measured material volume.…”

Section: Introductionmentioning

confidence: 99%

Complex Dielectric Permittivity Spectra of Rapeseed in the 20 MHz–3 GHz Frequency Range

et al. 2022

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Rapeseed is one of the most important sources of vegetable oil worldwide. Knowledge of the dielectric properties of rapeseed may be beneficial for moisture content determination and the optimization of microwave treatment processes. The aim of this research was to examine the complex dielectric permittivity spectra of rapeseed of moisture content from 8.3% to 16.1%. The measurements were performed in the 20 MHz–3 GHz frequency range with the use of a vector network analyzer and a coaxial transmission-line cell. The real part of dielectric permittivity significantly depended on the water content of the seeds. The obtained spectra were modeled with the use of a three-pole Debye model with bulk electrical conductivity. Because the highest-frequency pole was found near the high-frequency measurement band limit, the spectra were additionally modeled with the use of an approximate ABC model with two in-band Debye poles. The determined model parameters were found to be highly dependent on the water content of the seeds. The relations between these parameters and water content were analyzed.

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Comprehensive Investigation on Service Aged Power Transformer Insulating Oil After Decades of Effective Performance in Field

Mehmood

Nazir

et al. 2020

Arab J Sci Eng

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Dielectric properties of sunflower, rapeseed and commonly used mineral oil

Cited by 10 publications

References 22 publications

Normalization-Based Approach to Electric Motor BVR Related Capacitances Computation

Normalization-Based Approach to Electric Motor BVR Related Capacitances Computation

Complex Dielectric Permittivity Spectra of Rapeseed in the 20 MHz–3 GHz Frequency Range

Comprehensive Investigation on Service Aged Power Transformer Insulating Oil After Decades of Effective Performance in Field

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