| 1. |
- Bitsi, Konstantina, et al.
(författare)
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A Case Study of Pole-Phase Changing Induction Machine Performance
- 2022
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Ingår i: 2022 24Th European Conference On Power Electronics And Applications (EPE'22 ECCE EUROPE). - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- Pole-phase changing (PPC) induction machines (IMs) can achieve improved efficiency as well as wider torque-speed range compared to their fixed pole-phase counterparts. In this paper, a 4-pole IM is designed and evaluated in terms of its pole-phase changing performance.
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| 2. |
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| 3. |
- Bitsi, Konstantina, et al.
(författare)
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An Induction Machine with Wound Independently-Controlled Stator Coils
- 2019
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Ingår i: Proceedings of the 22nd International Conference on Electrical Machines and Systems (ICEMS). - : IEEE.
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Konferensbidrag (refereegranskat)abstract
- In this paper, a novel induction machine topology with wound, independently-controlled stator coils is presented. The introduced configuration of the stator-winding enables the individual energization and control of the coils in each stator slot. Therefore, the possibility of changing the number of poles and active phases in the stator winding during operation is explored in this study.
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| 4. |
- Bitsi, Konstantina, et al.
(författare)
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Design Aspects and Performance Evaluation of Pole-Phase Changing Induction Machines
- 2022
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 15:19, s. 7012-7012
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Tidskriftsartikel (refereegranskat)abstract
- Pole-phase changing induction machines (IMs) offer the capability to extend the torque-speed envelope compared to their fixed pole-phase counterparts. Dynamic pole-changing can achieve higher torque levels at lower speeds, utilizing higher pole numbers, and extended flux-weakening range with lower pole-number operations. This paper investigates the design impact on the optimum pole-phase changing behavior and respective split of the operating region to different pole-phase operations. Additionally, the improvement in terms of the overall torque per ampere capability and efficiency is illustrated. For the purposes of the analysis, two different IMs with wound independently-controlled stator coils (WICSC) and different original pole numbers are evaluated in an effort to quantify the extent of the benefits of pole-phase changing. These geometries correspond to machines that were originally designed with 2- and 6 magnetic poles, respectively. It is shown that, in the case of the original 2-pole WICSC machine, shifting to a higher pole number is notably beneficial in terms of efficiency in a significant part of the operating region, whereas in the original 6-pole, both higher and lower pole numbers significantly enhance the overall torque capability and efficiency. The results highlight the notable benefits of pole-phase changing IMs and offer deep insight towards the derivation of standard design guidelines for these machines.
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| 5. |
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| 6. |
- Bitsi, Konstantina, et al.
(författare)
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Many-objective Optimization of IPM and Induction Motors for Automotive Application
- 2019
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Konferensbidrag (refereegranskat)abstract
- This paper presents a Pareto-optimality-based optimization methodology suitable for the design of electrical motors in automotive applications. The proposed many-objective evolutionary algorithm is utilized in this study case for the optimization of an interior permanent-magnet (IPM) synchronous motor and an induction motor (IM), considering as criteria the motors' torque capability, efficiency as well as torque density. Finite-element (FE) models of the investigated motor topologies are developed and incorporated in the optimization process in order to ensure an accurate estimation of their electromagnetic performance. The attainment of the targeted specifications by the final optimal designs validates the efficacy of the implemented optimization algorithm.
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| 7. |
- Bitsi, Konstantina
(författare)
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On Electrical Machine Topologies for Electric Vehicle Applications
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The deployment of electric vehicles is considered a viable solution towardsreducing the global greenhouse-gas emissions and fossil-fuel consumption. Inorder to produce highly efficient and economically feasible electrical drivesystems, the selection of suitable electric motor designs is a key step.The target of this work is to identify, analyze and compare suitable elec-trical machine topologies for automotive applications based on highly coupledand conflicting criteria. For this purpose, an evolutionary multi-objective op-timization is developed that can yield a set of Pareto-optimal solutions and,thus, offer different compromises among the considered design-objectives. Theefficacy of the algorithm is demonstrated, rendering it an important tool forthe subsequent analysis.In the first part of this thesis, the investigation of pole-phase changinginduction machines is presented. A special induction machine topology withwound, independently-controlled stator coils (WICSC) is introduced. Thestator-winding configuration in this machine permits the individual energiza-tion and current control of the toroidal coil in each stator slot, thus facilitatingthe real-time change of both phase and pole number. The 2D magnetic and3D thermal finite-element method (FEM) models of this machine are devel-oped, as well as an analytical transient model of the current dynamics. Adetailed investigation of the behavior of pole-phase changing induction ma-chines and the impact of their design on the selection of optimum pole-phaseoperations throughout the entire operating region is performed. Specifically,three WICSC machines that were originally designed with 2, 4 and 6 fixedmagnetic poles are evaluated as pole-phase changing machines with the aim ofdetermining the overall improvement in terms of torque per ampere capabilityand efficiency.The second part of this work is focused on the design and performance ofaxial-flux induction machines (AFIMs). An electromagnetic sizing algorithmfor the design of AFIMs is developed, which adopts a geometrical approachto the design problem, while minimizing the use of empirical factors. Theeffectiveness of this algorithm is experimentally validated, using a commercialdouble-stator AFIM utilized as an integrated starter generator in a hybridelectric vehicle application. Moreover, in order to assess the benefits of pole-changing in axial-flux structures, the optimization of an interior-permanentmagnet synchronous machine, a radial-flux WICSC machine and a double-rotor axial-flux WICSC machine is carried out for a heavy vehicle applicationand the comparison of their Pareto-optimal solutions is presented.
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| 8. |
- Bitsi, Konstantina, et al.
(författare)
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Preliminary Electromagnetic Sizing of Axial-Flux Induction Machines
- 2020
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Ingår i: Proceedings of the 2020 International Conference on Electrical Machines (ICEM). - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- This paper presents a preliminary electromagnetic sizing algorithm for double-rotor axial-flux induction machines (DR-AFIMs). The proposed algorithm is based on a geometrical approach and limits the use of empirical factors and past experience. The sizing equations for all the main geometrical and operational machine parameters are derived and a concise outline of the electromagnetic sizing algorithm is provided. The efficacy of the implemented algorithm is validated using finiteelement DR-AFIM models. The achievement of the targeted specifications in the preliminary DR-AFIM designs is proven and demonstrated.
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| 9. |
- Haq, Omer Ikram ul, et al.
(författare)
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Generalized Harmonic Injection Strategy for Multiphase Induction Machine Control
- 2024
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Ingår i: IEEE transactions on energy conversion. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8969 .- 1558-0059. ; 39:2, s. 1245-1254
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Tidskriftsartikel (refereegranskat)abstract
- A multiphase induction machine model using vector space decomposition provides insights into many space harmonics through decoupled reference frames. These decoupled reference frames host specific space vectors related to particular space harmonics. Based on the physical winding configuration, these vector spaces can be excited independently and simultaneously for the production of torque. However, this approach may result in beat oscillations due to interference between excited vector spaces if proper synchronization of vector spaces is not maintained. This paper describes this phenomenon through experimental tests. Furthermore, a solution eliminating the beat oscillations is proposed while optimizing the stator current or rotor flux linkage peaks. The effectiveness of the solution is experimentally verified on a 9-phase induction machine.
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| 10. |
- Ikram Ul Haq, Omer, et al.
(författare)
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Online Winding Reconfiguration of a Multiphase Stator
- 2023
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Ingår i: 2023 IEEE 14th International Conference on Power Electronics and Drive Systems (PEDS). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 07-10
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Konferensbidrag (refereegranskat)abstract
- A multiphase machine control implementing vector space decomposition or harmonic plane decomposition for modeling purposes can reconfigure the stator's current distribution to generate magnetomotive force waves with different pole pair numbers simultaneously. The pole pair numbers are an integer multiple of the pole pairs generated by the physical winding configuration. This property can be used for reconfiguring the pole-pair number in real time or increasing the system's torque density. This paper studies the modeling and the impact of symmetrical and asymmetrical winding configurations on the pole-pair number reconfiguration. Furthermore, pole number transition is experimentally verified on a proposed winding configuration.
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