| 1. |
- Danyang, Cui, et al.
(author)
-
Design of Spoke Type Traction Motor with Ferrite Material for EV Application
- 2022
-
In: 2022 International Conference on Electrical Machines (ICEM). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 315-320
-
Conference paper (peer-reviewed)abstract
- Motor design for electric vehicle application using non-rare-earth permanent magnetic materials has become a research hotspot due to cost reduction and environmental issues. Among different motor topologies, permanent magnet synchronous motor (PMSM) with spoke-type ferrite magnets has great potential because of its competitive performance. In this paper, a novel design of a spoke-type synchronous motor using ferrite Y40 and non-magnetic steel material is presented, with optimizations on the overall structure and considerations on the effects of pole numbers. The performance of the designed motor verified with magnetic simulations shows that it has a high probability to be a candidate for replacing the conventional PMSM with rare-earth materials in Electric Vehicles (EV) application. © 2022 IEEE.
|
|
| 2. |
- Ekergård, Boel, 1985-, et al.
(author)
-
Eddy Current Losses in Solid Pole Shoes in a Two-Pole Permanent Magnet Motor
- 2021
-
In: Engineering. - : SCIRP. - 1947-3931 .- 1947-394X. ; 13:10, s. 536-543
-
Journal article (other academic/artistic)abstract
- The aim of this paper is to present the eddy current losses in solid pole shoes in a permanent magnet two-pole electric motor. In the presented paper, the authors have chosen to work with three different analytical models, Carter’s theory, Gibb’s theory and Lawrenson’s theory, each with different degree of accuracy and simplifications. The results from the analytical models all present relatively low eddy current losses, giving the designer valuable arguments to utilize solid pole shoes, as a rotor with solid poles is from a construction point of view a more suitable choice, increasing the mechanical stability and reducing the production cost, compared to the laminated design.
|
|
| 3. |
- Chatzigiannakou, Maria Angeliki, et al.
(author)
-
Numerical analysis of an Uppsala University WEC deployment by a barge for different sea states
- 2020
-
In: Ocean Engineering. - : Elsevier BV. - 0029-8018 .- 1873-5258. ; 205
-
Journal article (peer-reviewed)abstract
- Wave energy converters (WECs) have been deployed onshore, nearshore, and offshore to convert ocean wave movement into electricity. The exploitation of renewable energy sources has restrictions; in the case of wave energy, high installation, maintenance, and decommissioning costs have limited their commercial use. Moreover, these offshore operations can be compromised by safety issues. This paper draws attention to offshore operation safety of a WEC developed by Uppsala University. Specifically, this paper investigates what sea states are suitable for the safe deployment of a WEC from a barge. This study follows recommendations in DNV-RP-H103 for analysis of offshore operations, namely lifting through the wave zone. ANSYS Aqwa is used to find hydrodynamic forces acting on a typical barge, using frequency domain analysis. Based on these hydrodynamic simulation results and methodology given in DNV-RP-H103, tables are created to show the sea states that would allow for the safe installation of a WEC using a typical barge. Considered sea states have significant wave heights varying between 0 m and 3 m and the wave zero crossing periods varying between 3 s and 13 s. The WEC submersions are considered between 0 m and 7 m, i.e. when the WEC is in the air until it is fully submerged. © 2020 Elsevier Ltd
|
|
| 4. |
- Ekergård, Boel, 1985-, et al.
(author)
-
Longitudinal end effects in a linear wave power generator
- 2020
-
In: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:2
-
Journal article (peer-reviewed)abstract
- Even though the magnetic circuit of a linear electric machine is very similar to a rotating electric machine, they diverge in one fundamental property. The linear generator is open in both ends, i.e., the magnetic circuit is non-symmetric. This paper investigates and discusses the drawbacks of this non-symmetric design in a linear permanent magnet generator, installed in a wave energy conversion system. A two-dimensional geometry has been utilized for the numerical calculations in a finite element method simulation tool. The results present an increased cogging force and significant core losses in the translator as consequences of the longitudinal ends in the machine.
|
|
| 5. |
- Temiz, Irina, 1981-, et al.
(author)
-
Economic aspects of latching control for a wave energy converter with a direct drive linear generator power take-off
- 2018
-
In: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 128:Part A, s. 57-67
-
Journal article (peer-reviewed)abstract
- A wave energy converter (WEC) should be controlled in order to increase the average output power. In this paper, economic aspects of latching applied to a point absorbing WEC with a linear generator power take-off (PTO) are discussed. The capacity utilisation factor (CUF) is suggested to be used along with average absorbed power for control optimisation. Optimum and suboptimum latching controls are assessed for the WEC and compared with a constant damping PTO force control. The WEC performance is simulated using monochromatic waves for the wave conditions of the Wave Hub test site, UK. The linear wave theory is used in a hydro-mechanical two-body simulation model. It is shown that the latching controls possess considerable practical challenges significantly increasing the return of investment time periods.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Ekström, Rickard, et al.
(author)
-
Electrical damping of linear generators for wave energy converters : A review
- 2015
-
In: Renewable & sustainable energy reviews. - : Elsevier BV. - 1364-0321 .- 1879-0690. ; 42, s. 116-128
-
Research review (peer-reviewed)abstract
- The electrical damping of point-absorber wave energy converters is crucial to optimize the power output. Many circuit topologies have been proposed, but the possible increase in power absorption must be weighed against parameters such as cost, reliability and control system complexity. In this paper, the known electrical damping circuits are categorized, described and compared. The hydrodynamic damping of the buoy is covered, and how a linear generator can be used as a power take-off unit to apply a damping force. A qualitative comparison of the circuits is presented in the end. A more complex and costly power electronics system may be viable for wave energy converters (WECs) of large-scale power rating. However, for farm operation with small-scale WECs, a simpler and passive damping may be more suitable.
|
|
| 9. |
- Dolguntseva, Irina, 1981-, et al.
(author)
-
Risk based estimation of failure in a steel wire used for the wave energy converter connection line
- 2014
-
Conference paper (peer-reviewed)abstract
- The wave energy converter being developed at Uppsala University is of a point absorber type utilizing heaving motion of waves with a direct driven linear generator power take off. The point absorber, a buoy, is placed on the sea surface and is connected to the translator by a connection line. The connection line service life is of large importance for the lifetime of the entire device. Steel wire used as the connection line should be chosen to withstand loadings with different amplitude and frequency. In the present study, the risk of failure in the connection line is estimated.
|
|
| 10. |
|
|
