| 1. |
- Acquaviva, Alessandro, 1987, et al.
(författare)
-
Computationally Efficient Modeling of Electrical Machines With Cooling Jacket
- 2019
-
Ingår i: IEEE Transactions on Transportation Electrification. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 2332-7782. ; 5:3, s. 618-629
-
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.
|
|
| 2. |
- Andersson, Andreas, et al.
(författare)
-
Influence of Inverter Modulation Strategy on Electric Drive Efficiency and Perceived Sound Quality
- 2016
-
Ingår i: IEEE Transactions on Transportation Electrification. - : IEEE. - 2332-7782. ; 2:1, s. 24-35
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an evaluation of differentmodulation techniques and different levels of switching frequencyrandomization for a rear axle electrical drive unit used in auto-motive applications. Inverter and machine losses, and perceivedsound quality of high-frequency acoustic noise are investigated byfinite element calculations, experimental testing, and subjectivenoise assessment. Additionally, stator current harmonics, airgapflux density harmonics, and force density harmonics are comparedfor space vector modulation (SVM) and discontinuous pulsewidthmodulation through finite element modeling. The main conclusionis that, primarily in the field weakening region, significant energysavings can be achieved (up to 17% decrease in total inverter losseswith a switching frequency of 10 kHz). This is obtained withoutdeterioration of perceived sound quality by the use of discontinu-ous pulsewidth modulation with switching frequency randomiza-tion. Furthermore, randomization of the switching frequency doesnot improve the perceived sound quality of the acoustic noise whenusing SVM. However, for discontinuous pulsewidth modulation,improvements in perceived sound quality when randomizing theswitching frequency are observed, primarily below base speed.
|
|
| 3. |
- Andersson, A., et al.
(författare)
-
Motion sensorless IPMSM control using linear moving horizon estimation with luenberger observer state feedback
- 2018
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; 4:2, s. 464-473
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an investigation of motion sensorless control based on the frame work of moving horizon estimation (MHE), validated experimentally with a rear axle electrical drive unit used in automotive applications. Both steady-state performance and dynamic performance, including speed reversal, are investigated. In addition, a well-established active flux-based observer is implemented and referenced to objectively evaluate the proposed MHE. It is shown that the proposed solution is feasible, that the associated dynamic optimization problem can be solved in real time, while exploiting the attractiveness of the approach to obtain highly accurate estimates. Moreover, the absence of ${d}$-axis flux in the proposed solution is considered a significant strength. Conclusively, it turns the proposed solution into a universal solution for any synchronous motor, regardless of whether a PM, PM-assisted, or reluctance motor is used, nondependent on the presence of magnetic saliency.
|
|
| 4. |
- Bian, Xiaolei, et al.
(författare)
-
A two-step parameter optimization method for low-order model-based state of charge estimation
- 2020
-
Ingår i: IEEE Transactions on Transportation Electrification. - : Institute of Electrical and Electronics Engineers Inc.. - 2332-7782. ; , s. 1-1
-
Tidskriftsartikel (refereegranskat)abstract
- The state of charge (SOC) estimation is an enabling technique for the efficient management and control of lithium-ion batteries (LIBs). This paper proposes a novel method for online SOC estimation which manifest itself with both high accuracy and low complexity. Particularly, the particle swarm optimization (PSO) algorithm is exploited to optimize the model parameters to ensure a high modeling accuracy. Following this endeavor, the PSO algorithm is used to tune the error covariances of extended Kalman filter (EKF) leveraging the early-stage segmental data of LIB utilization. Within this PSO-based tuning framework, the searching boundary is derived by scrutinizing the error transition property of system. Experiments are performed to validate the proposed two-step PSO-optimized SOC estimation method. Results show that even by using a simple first-order model, the proposed method can give rise to a high SOC accuracy which is comparative to those using complex high-order models. The proposed method is validated to excavate fully the potential of model-based estimators so that the computationally expensive model upgrade can be avoided. IEEE
|
|
| 5. |
- Boscaglia, Luca, 1991, et al.
(författare)
-
Design and Verification of an Electrically Excited Synchronous Machine Rotor with Direct Oil Cooling for Truck Applications
- 2024
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- The rotor cooling in Electrically Excited Synchronous Machines (EESM) poses significant challenges due to the high power density resulting from active conductors necessary for generating the DC field, which in turn leads to substantial heat generation. Additionally, the rotor rotation further complicates the cooling system and contributes to mechanical losses. This paper presents the design of the rotor cooling system for a 200 kW EESM for truck applications. The system employs simultaneous direct cooling of the hollow shaft, rotor lamination, and rotor winding using mineral oil. The design is verified in simulations using Conjugate Heat Transfer (CHT) method by analyzing the oil flow and temperature distribution. Experimental tests are conducted on an 8-pole prototype rotor in stationary condition with a maximum coil heat loss of 4.7 kW, enabling 8x190 Aturns magneto-motive force per pole with 9.2 L/min oil flow rate. The results demonstrate the effectiveness of the cooling method in doubling the possible current density for continuous operation, from 5.05 A/mm2 to 10.1 A/mm2, keeping the Startup condition for more than 5 min and the maximum power for 20 minutes when the ventilation effect for the rotor rotation is included in simulation.
|
|
| 6. |
- Chen, Hao, et al.
(författare)
-
Electromagnetic Performance Investigation of A Brushless Electrically-Excited Synchronous Machine for Long-Distance Heavy-Duty Electric Vehicles
- 2024
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Long-distance heavy-duty electric vehicles, e.g., electric trucks, expect demanding requirements from the electric drive system, including high starting torque, high torque density, high power factor, high efficiency, etc. Permanent magnet synchronous machines (PMSMs) have been widely used for traction applications. However, the high cost and associated environmental issues due to the rare-earth permanent magnet material intensify researchers to explore new solutions. Accordingly, a brushless electrically-excited synchronous machine (EESM) is designed and investigated in this paper. The brushless EESM is also quantitatively compared with a PMSM candidate for the aforementioned application. Differing from conventional EESMs in which the brushes and slip rings are used for rotor field winding excitation, a contactless/brushless rotating transformer is adopted for the presented EESM to feed the rotor field winding. It is shown that the interior PMSM exhibits higher efficiency in low-speed region, but lower efficiency in high-speed region. By contrast, the brushless EESM exhibits lower efficiency in low-speed region, but much higher efficiency in high-speed region. Hence, the EESM is more suitable for long-distance heavy-duty electric vehicle applications where significant highspeed operations are required. Moreover, compared to the PMSM, the EESM is more cost-effective, sustainable, and environmentally friendly due to the absence of the rare-earth permanent magnet material. Both the PMSM and the EESM are prototyped and manufactured. Experimental results are provided to validate the effectiveness of the presented designs.
|
|
| 7. |
- Chen, Zhuo, et al.
(författare)
-
Reliability-Oriented Multi-Objective Optimization of Electrical Machines Considering Insulation Thermal Lifetime Prediction
- 2024
-
Ingår i: IEEE Transactions on Transportation Electrification. - : Institute of Electrical and Electronics Engineers (IEEE). - 2332-7782. ; 10:1, s. 2264-2276
-
Tidskriftsartikel (refereegranskat)abstract
- With the trend toward transportation electrification, the power density of electrical machines faces ever-increasing requirement owing to the stringent limit of weight, especially for aerospace applications. Conventionally, the reliability of electrical machines in such safety-critical application is guaranteed by considerable safety margins, i.e., the over-engineering approach, which prevents electrical machines from reaching higher power densities and leads to a design conflict. This paper proposes a reliability-oriented design approach for low-voltage electrical machines by integrating model-based lifetime prediction into a multi-objective optimization process. Accelerated thermal degradation tests are carried out on mainwall insulation and turn insulation, then the thermal degradation model is built to predict the lifetimes, accordingly. Thermal lifetime models are developed at several lifetime percentiles for both continuous duty and variable duty applications. Finally, a feasible reliability-oriented multi-objective optimization platform is established, based on which a study-case electrical machine for aerospace application is designed and optimized. The prototype is manufactured to verify the optimized performances.
|
|
| 8. |
- Dong, Haoxuan, et al.
(författare)
-
Flexible Eco-cruising Strategy for Connected and Automated Vehicles with Efficient Driving Lane Planning and Speed Optimization
- 2024
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; 10:1, s. 1530-1540
-
Tidskriftsartikel (refereegranskat)abstract
- Eco-cruising control of vehicles is a potential approach for improving vehicle energy efficiency and reducing travel time. However, many eco-cruising studies merely focused on vehicle longitudinal speed optimization but overlooked the lane change maneuvers, which may impair the benefits of eco-cruising when the vehicle encounters the slowly moving preceding vehicle. This study proposes a flexible eco-cruising strategy (FECS) with efficient driving lane planning and speed optimization capabilities simultaneously for connected and automated vehicles. The FECS is designed with a hierarchical control framework, where the first layer uses the Dijkstra algorithm to plan an efficient driving lane sequence considering the long-term effect of the preceding vehicles, then guides the second layer to optimize the vehicle’s speed for saving energy using trigonometric speed profile. The optimized driving trajectory is implemented in the third layer by regulating the speed and yaw angle for guaranteeing safe inter-vehicle distance when uncertainties are present. Finally, stochastic simulation with randomized traffic flows and typical case analysis based on real-world traffic data are conducted to demonstrate the performance of the FECS. The results manifest FECS’s capability of lowering driving costs in moderate-flow and free-flow traffic. However, we note that the benefits are less pronounced in congested-flow traffic.
|
|
| 9. |
- Geng, Zeyang, 1991, et al.
(författare)
-
A Time- and Cost-Effective Method for Entropic Coefficient Determination of a Large Commercial Battery Cell
- 2020
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; 6:1, s. 257-266
-
Tidskriftsartikel (refereegranskat)abstract
- The entropic coefficient of a lithium-ion battery cell is used to calculate the reversible heat of a battery during operation, which is a nonnegligible part of the battery thermal modeling. The contribution of this article is to propose a novel method to establish the entropic coefficient profile of a 26-Ah commercial pouch cell and compare the results with those obtained from the traditional potentiometric and calorimetric methods, and all are found to be in a good agreement. The originality of this article is to use a method, which consists of supplying a square pulse current waveform at a certain frequency, and thus, the resulting heat variation could be successfully linked to the input current using Fourier analysis. The current magnitudes used were 1 and 1.5 C, which are representative of the normal operation current in an electrified vehicle application. The method proposed is found to be cost efficient with a short experiment time and simple experiment setup. In fact, it can be used to characterize cells that are already mounted in a pack without access to a climate chamber or calorimeter.
|
|
| 10. |
- Geng, Zeyang, 1991, et al.
(författare)
-
Intermittent current interruption method for commercial lithium ion batteries aging characterization
- 2022
-
Ingår i: IEEE Transactions on Transportation Electrification. - 2332-7782. ; 8:2, s. 2985-2995
-
Tidskriftsartikel (refereegranskat)abstract
- In this article, a pioneering study is presented where the intermittent current interruption method is used to characterize the aging behaviour of commercial lithium ion batteries. With a very resource-efficient implementation, this method can track the battery resistive and diffusive behaviours over the entire state of charge range and be able to determine the aging throughout the life time of the batteries. In addition, the incremental capacity analysis can be carried out with the same data set. This method can provide measurement results with a high repeatability and produce equivalent information as the electrochemical impedance spectroscopy method. In this study, both the resistive and diffusive parameters increase with the battery capacity fading. This method does not require advanced test equipment and even with a 0.1 Hz sampling frequency, it is possible to extract usable parameters by prolonging the interruption length. Therefore, it has the potential to be easily implemented in the charging sequence in electric vehicles or stationary storage batteries for aging diagnostics.
|
|
