Analytical Field and Torque Analysis of a Reaction Sphere

Zhu, Linyu; Guo, Jian; Gill, Eberhard

doi:10.1109/tmag.2018.2871386

Cited by 9 publications

(8 citation statements)

References 20 publications

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“…Express the magnetic potential A θ written in complex form e jωt [27], where ω is the angular frequency of input currents, j is the imaginary unit. Then,…”

Section: − →mentioning

confidence: 99%

“…Based on the flux density distribution, the driving torque can be evaluated by Lorentz forces induced by eddy currents on the copper layer of the rotor. The electromagnetic torque arising from the rotor steel is negligible [27].…”

Section: − →mentioning

confidence: 99%

“…However, the analytical torque model (20) does not include these parameters. To authors' best knowledge, all the proposed analytical fields and torque models of inductive reaction spheres are developed based on the assumptions that the stator is slotless [27,[29][30][31]. Otherwise, the differential equation will be too complex to find an analytical solution.…”

Section: − →mentioning

confidence: 99%

“…The box constraints (22)-(26) are set to be consistent with the range of the sample spaces shown in Table 1. The linear inequality constraints are considered between coil turns, tooth thickness and tooth width: The coil turns and tooth thickness are limited by the tooth pitch (27); The coil turns and tooth width are limited by the fixed stator arc length (28). The parameters of the linear inequality constraints are validated by the lab possessed parts shown in Figure 9.…”

Section: Design Parameters Optimizationmentioning

confidence: 99%

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Design and Optimization of a Magnetically Levitated Inductive Reaction Sphere for Spacecraft Attitude Control

et al. 2019

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The inductive reaction sphere (RS) brings the benefit of simple, economical, and miniaturized design, and it is capable of multi-DOF torque generation. Thus, it is a suitable choice for the angular momentum exchange actuator in attitude control of micro-spacecrafts. To synthesize symmetric distribution of eddy currents and improve the speed and stability of rotation, a novel 4-pole winding design is proposed. However, the developed simplified analytical model shows that reduced pole number degrades the torque generation. To enhance the output torque of 4-pole RS, its curved cores and electromagnets are redesigned to enable the side teeth to be functional. As the analytical torque model for the RS with the slotted cores is not available, a constrained optimization problem is formulated, and the optimized parameters are calculated based on the prediction model from supported vector machine and finite element analysis. The lab prototypes are developed to validate the proposed design and test the speed performance. The experimental results show that the 4-pole RS prototype obtains a stable rotation over 700 rpm about X, Y and Z axis respectively with the angular momentum of 0.08 kg·m 2 /s, being superior to the 6-pole counterpart.

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“…Express the magnetic potential A θ written in complex form e jωt [27], where ω is the angular frequency of input currents, j is the imaginary unit. Then,…”

Section: − →mentioning

confidence: 99%

Section: − →mentioning

confidence: 99%

Section: − →mentioning

confidence: 99%

Section: Design Parameters Optimizationmentioning

confidence: 99%

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Design and Optimization of a Magnetically Levitated Inductive Reaction Sphere for Spacecraft Attitude Control

et al. 2019

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“…Region II and Region III are the copper layer and the steel core of the rotor, respectively. [16]. Assumptions employed in the field modeling are:…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis of Induction-Based Reaction Spheres

Zhu

Guo

Gill

2020

IEEE Trans. Ind. Electron.

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Induction-based reaction spheres have been presented in many references and their performances are normally investigated through experiments or numerical simulations which are time-consuming. Here, an analytical way is presented and it enables researchers to evaluate a new design quickly. The presented performance analysis is conducted through the classical equivalent circuit approach. Involved circuit parameters are determined through the magnetic flux density distribution which is a function of design variables. Based on this, the steady state torque-speed curve and the achievable maximum driving torque T * are identified. T * deviates from the maximum torque obtained from numerical simulations by only 3%. For validation, the presented performance analysis method is applied to an experimental case. Mean absolute percentage errors of predicted torque-speed curves are within 23% and mainly caused by end effects. The presented performance analysis method is generally applicable to induction-based spherical actuators, not only limited to reaction spheres. Additionally, since influences of design variables of the actuator have been formulated analytically through the determined circuit parameters, performance optimizations could be greatly facilitated.

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