Transient Roebel Bar Force Calculation in Large Salient-Pole Synchronous Machines

Meiswinkel, Marius Wenzel; Ebrahimi, Amir; Wohlers, Constantin; Neschitsch, Tim

doi:10.1109/access.2020.3046789

Cited by 3 publications

(3 citation statements)

References 11 publications

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“…In comparison, the CSSIM always has a higher error than the DSSIM with a peak value at 8.5% on currents, meaning over 17% on losses. In the context of high competition towards efficiency increase and reduction of measurement tolerances on efficiencies in hydro-generators 1 , there is a strong need for more precise computation methods and the DSSIM clearly responds to this need.…”

Section: B Dssim Vs Cssimmentioning

confidence: 99%

“…Thus only, the saturation component is missing with respect to the DSSIM. As it can be seen, the DSSIM has here also a significantly 1 In today's tender, the IEC tolerance does not apply anymore. The clients are only accepting a reduced tolerance of about 2-3%.…”

Section: B Dssim Vs Cssimmentioning

confidence: 99%

“…A non-uniform loss distribution over the strands can cause bar damages, which has been documented since the 1970s for large AC machines. They can also cause uneven local forces [1] and eddy current dissipation [2]. In reference [3], circulating currents are measured using search coils.…”

Section: Introductionmentioning

confidence: 99%

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A Differential Strand-Slot Inductance Model for Improved Compensation of Circulating Currents in the Core Part of Large AC Machines

Maurer

Nøland

2022

IEEE Trans. Energy Convers.

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The Roebel bar conventional design of large AC machines uses the classical strand-slot inductance model (CSSIM). Suitable alternatives are missing as the CSSIM is favored for its inherent simplicity based on the ideally permeable iron core hypothesis. However, saturated armature slots can lead to high variations of the slot inductance, where the CSSIM cannot represent this precisely. An accurate prediction of the strand inductances is crucial when optimizing the transpositions of large Roebel bars to be competitive on efficiency and low measurement tolerances. This fact is crucial in under-roebeling, having less than a 360-degree transposition over the active part. In the end, the goal is to compensate the winding overhang parasitic field with the slot-parasitic field. This paper proposes a differential strand-slot inductance model (DSSIM) based on the concept of differential inductance (DI). It is compatible with a circuital lumped-element model (LEM) that considers the strand topology, geometrical dimensions, saturation level, and smallscale effects. Numerical simulations showcase the performance improvement of the DSSIM against known models. Finally, a 20strand prototype of a slot model with actual Robel bar strands corresponding to a simplified bar cross-section in a large AC machine's slot demonstrates the presented DSSIM's precision.

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Section: B Dssim Vs Cssimmentioning

confidence: 99%

Section: B Dssim Vs Cssimmentioning

confidence: 99%

See 1 more Smart Citation

A Differential Strand-Slot Inductance Model for Improved Compensation of Circulating Currents in the Core Part of Large AC Machines

Maurer

Nøland

2022

IEEE Trans. Energy Convers.

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Thermal Modeling and Experimental Validation in the Rotor Region of Hydrogenerator With Different Rotor Structures

et al. 2021

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Thermal management is often considered a bottleneck in the pursuit of the next generation hydrogenerator in the electric power system. Overheating of the complex rotor parts has become one of the main problems affecting safe and stable hydrogenerator operation. In this paper, a 250 MW hydrogenerator is analyzed. The transient electromagnetic field of the hydrogenerator is calculated and the losses of the rotor parts are obtained. The rotation of the hydrogenerator rotor is considered. Three-dimensional fluid and thermal mathematic and physical models of the hydrogenerator are established. The loss values from electromagnetic field calculations are applied to the rotor parts as heat sources in the temperature field. After solving the fluid and thermal equations of fluid-solid conjugated heat transfer, influence of the structures of rotor support plate, rotor pole body insulation, and rotor excitation winding on the fluid flow and temperature distribution in the rotor region of hydrogenerator is studied using the finite volume method. The calculated temperature result of rotor excitation winding is compared with the measured value. The calculated temperature result agrees well with the measured value. It provides an important reference for optimizing the rotor structure of the larger hydrogenerator.

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Torque Estimation in Rotating Electrical Machines

Ebrahimi

2023

2023 13th International Conference on Power, Energy and Electrical Engineering (CPEEE)

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Transient Roebel Bar Force Calculation in Large Salient-Pole Synchronous Machines

Cited by 3 publications

References 11 publications

A Differential Strand-Slot Inductance Model for Improved Compensation of Circulating Currents in the Core Part of Large AC Machines

A Differential Strand-Slot Inductance Model for Improved Compensation of Circulating Currents in the Core Part of Large AC Machines

Thermal Modeling and Experimental Validation in the Rotor Region of Hydrogenerator With Different Rotor Structures

Torque Estimation in Rotating Electrical Machines

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