Improved quasi-Z-source dual-inverter for open-end winding induction motor drives

Li, Chunjie; Huang, Wei‐Ping; Bu, Feifei

doi:10.1109/icems.2015.7385059

“…Because of the skin effect, the stator core's impedance is significantly frequency-dependent. In order to account for the skin and proximity effects, ladder circuits are used to model the resistances and inductances in [107].…”

Section: Analytical Calculation Of Circulating Currentmentioning

confidence: 99%

“…Because of the skin effect, the stator core's impedance is significantly frequency-dependent. In order to account for the skin and proximity effects, ladder circuits are used to model the resistances and inductances in [107]. Analysis approaches may be used to determine the impedance of the circulating current loop based on a few simplified assumptions.…”

Section: Analytical Calculation Of Circulating Currentmentioning

confidence: 99%

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

Tawfiq

¹

,

Güleç

²

,

Sergeant

³

2023

Machines

14

0

View full text Add to dashboard Cite

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.

show abstract

“…Additionally, bearings can be affected by Electric Discharge Machining (EDM) bearing currents which have an impulsive behaviour and are directly linked to the common-mode-voltage V COM by Bearing Voltage Ratio (BVR) which works as a divider generated by the machine parasitic capacitances [7]. Many works proposed different modellings for the capacitance estimations based on the measurements [8]- [9], using 2D [10]- [11] and 3D [12] Finite Element Analysis (FEA). It is possible to mitigate these high frequency parasitic currents by modification or implementation on the machine design.…”

Section: Introductionmentioning

confidence: 99%

Novel Stator Slot Opening to Reduce Electrical Machine Bearing Currents

Gaetano

¹

,

Zhu

²

,

Sun

³

et al. 2023

View full text Add to dashboard Cite

Ball bearings are largely used in electrical machines, where the high frequency common mode currents affect their lifetime. This document presents a novel Zig-Zag stator slot opening geometry to reduce the winding-to-rotor capacitance Cwr with the consequent reduction of Bearing Voltage Ratio and electrical discharge machining bearing currents. An improved analytical model to permit the calculation of Cwr for unusual slot opening geometries is implemented. Electrostatic and electromagnetic Finite Element Analysis comparisons between the Zig-Zag, oblique and original (classical slot opening configuration) machines are performed. These comparisons suggest that the Zig-Zag model presents the best performance in terms of Bearing Voltage Ratio reduction, while keeping torque performance close to the original machine. An additional comparison between the novel Zig-Zag model and the classical one with reduced slot opening to have the same Cwr values is proposed, showing an higher degradation in terms of torque performance for the latter. The study shows that the Zig-Zag model could be a good candidate to reduce effectively electrical machine bearing currents. A validation test is proposed on two motorette prototypes having classical and Zig-Zag slot opening configurations, respectively. Moreover, the improved analytical method can be helpful for engineers and researchers to calculate Cwr with a good accuracy for unusual slot opening geometries.

show abstract

Novel Stator Slot Opening to Reduce Electrical Machine Bearing Currents

Gaetano,

Zhu,

Sun

et al. 2023

2023 IEEE International Magnetic Conference - Short Papers (INTERMAG Short Papers)

0

View full text Add to dashboard Cite

Ball bearings are largely used in electrical machines, where the high frequency common mode currents affect their lifetime. This document presents a novel Zig-Zag stator slot opening geometry to reduce the winding-to-rotor capacitance Cwr with the consequent reduction of Bearing Voltage Ratio and electrical discharge machining bearing currents. An improved analytical model to permit the calculation of Cwr for unusual slot opening geometries is implemented. Electrostatic and electromagnetic Finite Element Analysis comparisons between the Zig-Zag, oblique and original (classical slot opening configuration) machines are performed. These comparisons suggest that the Zig-Zag model presents the best performance in terms of Bearing Voltage Ratio reduction, while keeping torque performance close to the original machine. An additional comparison between the novel Zig-Zag model and the classical one with reduced slot opening to have the same Cwr values is proposed, showing an higher degradation in terms of torque performance for the latter. The study shows that the Zig-Zag model could be a good candidate to reduce effectively electrical machine bearing currents. A validation test is proposed on two motorette prototypes having classical and Zig-Zag slot opening configurations, respectively. Moreover, the improved analytical method can be helpful for engineers and researchers to calculate Cwr with a good accuracy for unusual slot opening geometries.

show abstract

Improved quasi-Z-source dual-inverter for open-end winding induction motor drives

Cited by 5 publications

References 14 publications

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

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

Novel Stator Slot Opening to Reduce Electrical Machine Bearing Currents

Novel Stator Slot Opening to Reduce Electrical Machine Bearing Currents

Contact Info

Product

Resources

About