An Investigation into the Effect of Bearing Grease Degradation on the High-frequency $dv/dt$ Bearing Current in an Inverter-fed Motor System

Zheng, Jingnan; Xiang, Dan; Li, Hao; Quach, Duc-Cuong

doi:10.1109/icpre52634.2021.9635227

Cited by 3 publications

(2 citation statements)

References 11 publications

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“…Moreover, determining the extent of potentially dangerous bearing currents is difficult since bearings vary depending on machine size and application. Consequently, researchers often define the apparent bearing current density (J b ) and conclude that bearing current densities lower than 0.8 A/mm 2 are tolerable for bearing life [85][86][87]. The use of shaft brushes, such as the AEGIS Shaft Voltage Probe [80,88], in close proximity to the bearing provides an easy but intrusive technique to monitor the bearing voltage with a wide bandwidth as shown in Figure 10.…”

Section: Measurements Of Bearing Current and Shaft Voltagementioning

confidence: 99%

Bearing Current and Shaft Voltage in Electrical Machines: A Comprehensive Research Review

2023

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The reliability assessment of electric machines plays a very critical role in today’s engineering world. The reliability assessment requires a good understanding of electric motors and their root causes. Electric machines mostly fail due to mechanical problems and bearing damage is the main source of this. The bearings can be damaged by mechanical, electrical, and thermal stresses. Among all stresses, the researcher should give special attention to the electrical one, which is bearing current and shaft voltage. This review paper introduces a comprehensive study of bearing current and shaft voltage for inverter-fed electric machines. This study aims to discuss several motor failure processes, as well as the sources and definitions of bearing current and shaft voltage. The different kinds of bearing currents are addressed and the parasitic capacitances, which are the key component to describe bearing current, are determined. Several measurement approaches of bearing current will be discussed. Furthermore, modeling of bearing current will be covered together with the machine’s parasitic capacitances. Moreover, the different bearing current mitigation techniques, as described in many papers, will be thoroughly addressed. The use of rewound multiphase machines for mitigation of bearing current will be proposed and compared to a three-phase machine. Finally, various pulse width modulation techniques of multiphase systems that reduce bearing current and shaft voltage will be investigated, and the findings described in the literature will be summarized for all techniques.

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Section: Measurements Of Bearing Current and Shaft Voltagementioning

confidence: 99%

Bearing Current and Shaft Voltage in Electrical Machines: A Comprehensive Research Review

2023

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“…According to Tischmacher et al [95], the shaft voltage of conductive greases is lower than that of non-conductive greases, but their qualities are similar to non-conductive greases after the operation. Zheng et al [96] found that the high-frequency dv/dt bearing current amplitude increased with the degradation of the bearing grease.…”

Section: Lubricant Greasementioning

confidence: 99%

Motor Bearing Damage Induced by Bearing Current: A Review

Xue

Han

et al. 2022

Machines

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The occurrence of the motor shaft voltage and bearing current caused by the inverter will aggravate bearing damage and lead to the premature failure of bearings. Many types of equipment are being shut down due to bearing currents, such as filters, insulated bearings and grounding brushes. Traditional suppression measures cannot eliminate the bearing current and the bearing damage mechanism under the bearing current is not clear. In this paper, the damage caused by the bearing current to bearings is analyzed in detail. The influences of different working conditions on the bearing current and the damage caused are discussed. The source of bearing currents is introduced and the bearing current model under different working conditions is reviewed. An outlook for future studies is proposed, based on the current research status and challenges.

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