| 1. |
- Lundmark, Sonja, 1966, et al.
(författare)
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Heat transfer coefficients in a coupled 3-D model of a liquid-cooled IPM traction motor compared with measurements
- 2019
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Ingår i: 2019 14th International Conference on Ecological Vehicles and Renewable Energies, EVER 2019. - 9781728137032
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Konferensbidrag (refereegranskat)abstract
- Modelling of electrical machines is constantly refined and it is now possible to couple numerical thermal models and electromagnetic models, thereby considering the thermal effects on motor materials. In this paper it is shown how a 3-D model of an interior permanent magnet (IPM) motor, including losses in the end windings and the effect of air and liquid cooling can be made where simulation results are compared with measurements. Further, it is shown how the coolant inlet temperature and volumetric flow rate affects the heat transfer coefficient of the cooling duct for some load points within the torquespeed range of the motor.
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| 2. |
- Acquaviva, Alessandro, 1987, et al.
(författare)
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Computationally Efficient Modeling of Electrical Machines With Cooling Jacket
- 2019
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Ingår i: IEEE Transactions on Transportation Electrification. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2332-7782. ; 5:3, s. 618-629
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Tidskriftsartikel (refereegranskat)abstract
- Modeling of electrical machines is a multiphysics problem. Depending on the phenomena of interest and the computational time constraint, this can be done at different levels of detail. In this article, the main approaches to model the thermal behavior of electrical machines with a liquid cooled casing around the stator (often referred to as cooling jacket) are analyzed and a novel approach is presented. The proposed method aims at creating computationally efficient 3-D multiphysics models of electrical machines with liquid cooled jacket. This model is based on the assumption of a fully developed flow in the cooling jacket which allows to scale the computational fluid dynamics (CFD) simulation to 1-D. The slot with a two layer concentrated winding and potting material is modeled using a composite material comprising of both the conductors and slot filler. Similarly, a unified material is used to model the end-windings. Experimental results on a traction machine for vehicle applications are presented showing good agreement with the simulations. Also, a comparison with a 3-D CFD is presented to verify the pressure drop in the pipe bend. Finally, the model is used to simulate a dynamic load cycle, which would be computationally extremely demanding with combined 3-D CFD and thermal FEA of the machine and its cooling.
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| 3. |
- Diana, Michela, 1987, et al.
(författare)
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High Voltage Direct Drive Generators with Multiphase Single Layer Fractional Slot Concentrated Windings
- 2020
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Ingår i: Proceedings - 2020 International Conference on Electrical Machines, ICEM 2020. - 9781728199450 ; , s. 1903-1909
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Konferensbidrag (refereegranskat)abstract
- This paper presents design considerations for a high voltage direct drive generator for an high voltage DC offshore wind park application. The paper investigates 3-phase and 6-phase fractional slot concentrated windings for high voltage surface mounted permanent magnet machines. The paper focuses on q=2 /5, 50 pole-pairs and q=4 /11, 55 pole-pairs machines in the single layer configuration with different number of phases. The analysis has been executed by both analytical and finite element analysis methods. The paper reports the results of the comparison in terms of torque performance, power factor and losses, aiming to demonstrate the advantages and limitations of the use of fractional slot concentrated windings single layer multiphase generators for high voltage wind turbines. It is found that single layer multiphase configurations can improve the performance of the generator in terms of torque density, torque ripple and efficiency, but the low power factor can be a limiting factor for the exploitation of this technology for high voltage high power generators for wind turbine applications. In this paper, a solution to improve the PF without sacrificing the efficiency is proposed.
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| 4. |
- Diana, Michela, 1987, et al.
(författare)
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High Voltage Direct Driven Wind Turbine Generator
- 2020
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Ingår i: ECCE 2020 - IEEE Energy Conversion Congress and Exposition. ; , s. 1787-1793
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Konferensbidrag (refereegranskat)abstract
- This paper reports the design consideration for a high voltage direct drive generator suitable for a HVDC offshore wind park application. The study considers both concentrated overlapping and non overlapping windings in different slot/pole combinations for the design of a 35kV , 20MW permanent magnet synchronous machine. The analysis has been executed by finite element analysis. Among different slot/pole number solutions, two has been identified as worth of attention: q = 1, 42 pole-pairs machine and q = 2/5, 50 pole-pairs machine. The paper reports the results of the comparison in terms torque performances, power factor, efficiency, and annual energy production and annual energy losses.
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| 5. |
- Dubar, Christian, 1984, et al.
(författare)
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An electric machine design procedure that includes multiple cost scenarios
- 2016
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Ingår i: 18th European Conference on Power Electronics and Applications, EPE 2016 ECCE Europe; Karlsruhe; Germany; 5 - 9 September 2016. - 2325-0313. - 9789075815245 ; , s. Art no 7695477-
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Konferensbidrag (refereegranskat)abstract
- This paper presents a procedure to include different cost scenarios of raw materials into the design of electric machines. The ratio between performance and material cost is visualized over a number of different cost scenarios. It is thereby possible to see not only if a specific design is competitive under the current market circumstances, but also to compare the sensitiveness for fluctuations in the material prices.
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| 6. |
- Dubar, Christian, 1984, et al.
(författare)
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Design of an online temperature monitoring system for an experimental IPMSM
- 2016
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Ingår i: Proceedings 22nd International Conference on Electrical Machines, ICEM 2016. Lausanne; Switzerland; 4-7 September 2016. - 9781509025381 ; , s. 1533-1538
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Konferensbidrag (refereegranskat)abstract
- The overall performance of an electric machine is closely linked to the thermal design of the machine and there is a trend to include more thermal analysis into the machine design procedure in academic literature. Thus, there is also a motivation to prototype experimental machines for accurate validations of the thermal analysis. One of the challenges is to measure rotor temperatures online while the machine is in operation. This paper presents some of the experience from designing an online temperature monitoring system for an experimental IPMSM. In total, 32 sensors was successfully placed inside the 3.4 liter volume of the small IPMSM and temperature data was transmitted from the rotor in the end of the shaft, using infrared light. It was found that the online temperature monitoring system was very reliable. Both the used analog and digital sensors exhibit equal results and EMI immunity, when placed inside the electromagnetically noisy environment inside the machine.
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| 7. |
- Grunditz, Emma, 1980, et al.
(författare)
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Thermal capability of electric vehicle PMSM with different slot areas via thermal network analysis
- 2021
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Ingår i: eTransportation. - : Elsevier BV. - 2590-1168. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the effect that a varied stator slot size has on the efficiency and thermal capability of a permanent magnet synchronous machine for an electric vehicle, is evaluated and quantified. A machine with four differently sized slot areas was electromagnetically evaluated with finite element analysis, and thermally with a lumped parameter network model. By decreasing the slot size while keeping other dimensions fixed, the core losses reduce due to the wider magnetic path, whereas the winding losses increase. Additionally, a higher maximum torque is reached due to reduced saturation. Results are compared in the machine's torque-speed operating area regarding machine-part and total losses, continuous torque and transient overload capability, as well as during 19 low, middle and high-speed drive cycles regarding energy losses and peak winding temperature. The largest slot showed the lowest winding losses and thus the highest thermally limited torque capability. In contrast, the energy losses with the largest slot were the highest in 13 of the drive cycles, and the lowest in 11 of them with the smallest slot due to its lower part load (i.e. core) losses. The smallest slot would also result in the lowest material cost since it has the least copper.
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| 8. |
- Grunditz, Emma, 1980, et al.
(författare)
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Three traction motors with different magnet materials — Influence on cost, losses, vehicle performance, energy use and environmental impact
- 2018
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Ingår i: 2018 Thirteenth International Conference on Ecological Vehicles and Renewable Energies (EVER). ; , s. 1-13
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Konferensbidrag (refereegranskat)abstract
- The aim of reducing both cost and environmental impact of automotive electric traction motors motivates the examination of motor performance when using magnets of varying strength and materials. Such investigations have attracted increasing interest in recent years. Given the same take-off torque capability, three motors are compared that have the same stator geometry but different magnet materials in the rotor; two PMSMs - one with Nd(Dy)FeB and one with SmCo magnets - and one PMaSynRM with strontium-ferrite magnets. To compensate the weaker magnets, their corresponding core stacks are prolonged. The resulting torque capability at high speed levels is lower for the SmCo PMSM and ferrite PMaSynRM compared to the Nd(Dy)FeB PMSM. The ferrite PMaSynRM has the poorest dynamic vehicle performance, but also the lowest energy losses over a wide range of drive cycles. In addition, the ferrite based motor option has the lowest environmental impact during manufacturing as well as the lowest material cost estimate. The SmCo motor has slightly lower losses than the Nd(Dy)FeB, but the highest material cost. Certainly, the result signals that further in-depth studies of the described PMaSynRM are of high relevance.
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| 9. |
- Josefsson, Oskar, 1985, et al.
(författare)
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Assessment of a Multilevel Converter for a PHEV charge and traction application
- 2010
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Ingår i: XIX International Conference on Electrical Machines (ICEM), 2010, Rome, 6-8 Sept. 2010. - 9781424441747
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Konferensbidrag (refereegranskat)abstract
- With the Plug in Hybrid Electric Vehicle (PHEV) the introduction of a charger has to be done. A standalone onboard charger will increase both weight and cost of the vehicle. A better option is the integration of the charging function into the already existing propulsion converter. The aim of this paper is to assess the multilevel converter as an integrated vehicle charge and propulsion converter. A comparison between conventional converter technology and multilevel converter technology is made both on component level and system level. The investigation, based on calculations, simulations and measurements, points to some features that can; increase the efficiency of the total system; increase the life time of the energy storage; and increase the utilization of the energy storage. However, the investigation also points to features that can increase the cost and complexity of the system and reduce efficiency in certain operation points.
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| 10. |
- Josefsson, Oskar, 1985, et al.
(författare)
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Evaluation and comparison of a two-level and a multilevel inverter for an EV using a modulized battery topology
- 2012
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Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2162-4704 .- 2577-1647. - 9781467324199 ; , s. 2949 - 2956
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Konferensbidrag (refereegranskat)abstract
- This paper analytically evaluates when it is suitable to use a multilevel inverter in an electrified vehicle. The multilevel inverter is compared to a classical two level inverter for different operation points and for different drive cycles.Reliable models of the components which build up the inverter are needed in order to be able to calculate the losses. Analytical models for the losses are developed to be able to compare the two inverters. Since the two inverters utilizes the battery in different ways the losses in the battery is also considered.It is shown that in certain operation points it is an advantage to use a multilevel inverter to achieve a higher efficiency for the inverter but is also shown that in some operation points the multilevel inverter increases the losses in the battery. However, it is worth mentioning that there is a controllability on where in the battery the losses should take place.The multilevel inverter can also be used as a two level inverter in these operation points to minimize the battery losses.
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