| 1. |
- Cui, Chao, et al.
(författare)
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A Full Power Range ZVS Control Technology for Bidirectional Inductive Power Transfer System
- 2020
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Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2577-1647 .- 2162-4704. ; 2020-October, s. 3861-3865
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Konferensbidrag (refereegranskat)abstract
- Inductive Power Transfer (IPT) technology has received extensive application research due to its safety and convenience. As a circuit topology with high efficiency and high controllability, dual active bridge (DAB) has been used in IPT system in recent years. In high-power applications, the EMI generated by the power device switch becomes more significant, which in turn negatively affects the efficiency and even the stability of the IPT system. There are several ways to reduce EMI. This article studies from the perspective of zero voltage switching (ZVS) of the DAB. When the duty cycle of the full bridge changes, the soft switching may not be maintained. This paper calculates and analyzes the ZVS operating range of the system under different situations. On this basis, a control method is proposed to achieve ZVS in the full power range of the system by adjusting the bilateral load angle. And the efficiency and stability of the system are improved. The correctness of the above theory and control method is verified through simulations.
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| 2. |
- Godaly, Gabriela, et al.
(författare)
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Urinary Tract Infection Molecular Mechanisms and Clinical Translation.
- 2016
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Ingår i: Pathogens. - : MDPI AG. - 2076-0817. ; 5:1
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Forskningsöversikt (refereegranskat)abstract
- Rapid developments in infection biology create new and exciting options for individualized diagnostics and therapy. Such new practices are needed to improve patient survival and reduce morbidity. Molecular determinants of host resistance to infection are being characterized, making it possible to identify susceptible individuals and to predict their risk for future morbidity. Immunotherapy is emerging as a new strategy to treat infections worldwide and controlled boosting of the host immune defense represents an important therapeutic alternative to antibiotics. In proof of concept studies, we have demonstrated that this approach is feasible. The long-term goal is not just to remove the pathogens but to also develop technologies that restore resistance to infection in disease-prone patients and devise personalized therapeutic interventions. Here, we discuss some approaches to reaching these goals, in patients with urinary tract infection (UTI). We describe critical host signaling pathways that define symptoms and pathology and the genetic control of innate immune responses that balance protection against tissue damage. For some of these genes, human relevance has been documented in clinical studies, identifying them as potential targets for immune-modulatory therapies, as a complement to antibiotics.
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| 3. |
- Huang, Xiaoliang, 1985, et al.
(författare)
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A Reconfigurable Battery Supercapacitor Hybrid Energy System with Active Balancing for Vehicle Applications
- 2021
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Ingår i: Proceedings - 2021 IEEE 19th International Power Electronics and Motion Control Conference, PEMC 2021. ; , s. 231-236
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Konferensbidrag (refereegranskat)abstract
- The concept of reconfigurable energy systems has become more and more popular in recent years for electric vehicle applications, which can largely enhance battery performance and extend battery lifetime. Active balancing is an advanced function realized by battery management systems (BMSs) to improve energy efficiencies and avoid potential over-charging risks. This paper proposed a reconfigurable hybrid energy system (HESS) that consists of one supercapacitor module, n lithium-ion modules, one DC/DC converter, and 3n switches, to enhance energy system performance with fast active balancing. The developed algorithms are to find out all possible configurations for a given lithium-ion module number and module section number, and the best configuration is selected based on the fastest balancing speed requirement. The proposed topology and algorithms are finally verified by simulations under standard vehicle driving cycles.
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| 4. |
- Huang, Xiaoliang, 1985, et al.
(författare)
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Experimental evaluation of conductor insulations used in e-mobility traction motors
- 2021
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Ingår i: Proceedings - 2021 IEEE Workshop on Electrical Machines Design, Control and Diagnosis, WEMDCD 2021. ; , s. 249-253
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Konferensbidrag (refereegranskat)abstract
- Application of high switching frequency converters providing signals with a high level of dv/dt has resulted in an increased stress on the traction motors insulation system. This paper presents an investigation done on the insulation materials developed for traction motors used in E-mobility applications and built using form or hairpin windings. Since the high dv/dt results in a high voltage difference between the conductors, focus in this paper is placed on the conductor insulation referred as 'primary insulation'. An experimental setup is developed and test samples using different insulation materials are made. A comparison between the life-time of the non-corona resistant and corona-resistant materials are made. Additionally, influence of the temperature, voltage and thickness on the insulation system life-time is evaluated. The test results show that corona resistant Kapton® ECRC materials with different thicknesses may be considered as proper candidates for traction motors designed and produced for electrification market fed by high switching frequency converters.
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| 5. |
- Jiang, Bowen, 1993, et al.
(författare)
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A New Battery Active Balancing Method with Supercapacitor Considering Regeneration Process
- 2020
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Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2577-1647 .- 2162-4704. ; 2020-October:18 October 2020, s. 2364-2369
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Konferensbidrag (refereegranskat)abstract
- Lithium-ion batteries have been widely used in new energy vehicles (NEV) as large energy storage systems (ESS). It is necessary to balance series-connected cells to avoid over-charging or over-discharging as well as to improve the amount of usable energy. This paper starts with a comprehensive review of the existing strategies and gives a battery balancing category. A new balancing topology with its control algorithms is then introduced. A supercapacitor is used in the balancing circuit which replaces the highest state of charge (SOC) cell and is charged during the vehicle regeneration process. The supercapacitor also transfers energy to the lowest SOC cell after it is fully charged. This new strategy can not only improve the balancing efficiency due to fewer times of energy conversion but also reduce the required balancing time compared to single capacitor balancing.
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| 6. |
- Jiang, Bowen, 1993, et al.
(författare)
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A Novel Approach of Electric Powertrain Co-Simulation with High Fidelity Vehicle Model
- 2022
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Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2577-1647 .- 2162-4704. ; 2022-October
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Konferensbidrag (refereegranskat)abstract
- This paper presents a co-simulation approach for an electric vehicle which combines dynamic models of electric machine, inverter, gearbox in PLECS with high fidelity models of driver, autobody, wheel, road and environment in CarMaker. Lumped parameter thermal networks to model heat dissipation in the electric machine and the inverter are also included. The aim is to demonstrate versatility of the co-simulation method in analyzing effects of driver behaviors on thermal performance of electric machine and inverter. Co-simulation results using two simulation tools are compared to those obtained entirely using a single tool. It is observed that performing co-simulation using low fidelity vehicle model results in underestimation of vehicle speed. Further, the impacts of three different driver models on the temperatures of electric machine windings and semiconductor junctions are analyzed. Differences of 30% and 25% in the maximum temperature are observed respectively between an aggressive and a defensive driver.
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| 7. |
- Jiang, Bowen, 1993, et al.
(författare)
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Accelerated destructive experiment design of motor stator winding insulation systems
- 2021
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Ingår i: Proceedings - 2021 IEEE Workshop on Electrical Machines Design, Control and Diagnosis, WEMDCD 2021. ; , s. 225-230
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Konferensbidrag (refereegranskat)abstract
- Electric motors, being as key components in battery electric vehicles (BEVs), need to provide high power and torque to meet people's expectations on vehicles' performance. However, since the electric motors used in vehicles shall be driven by pulse width modulated (PWM) inverters, the high alternating voltages and currents applied to stator windings usually give extremely big electrical stress to their insulation systems, which may bring reductions to motors' lifetimes. Factors, such as environmental temperatures, voltage derivatives (dv/dt), insulation materials, and cover overlap percentages all affect the winding aging speeds in different degrees. To have shorter experimental time, this paper proposed a new method to do accelerated destructive experiments on insulation systems of motor stator windings. This designed method has stable measurements as well as precise detections on insulation failures and can study multiple insulation influencers. The functionalities of this insulation testing system have been finally verified by experiments using stator windings covered with Kapton® FN films.
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| 8. |
- Jiang, Bowen, 1993, et al.
(författare)
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Real-Time FPGA/CPU-Based Simulation of a Full-Electric Vehicle Integrated with a High-Fidelity Electric Drive Model
- 2022
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 15:5
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Tidskriftsartikel (refereegranskat)abstract
- Real-time simulations refer to the simulations of a physical system where model equations for one time-step are solved within the same time period as in reality. An FPGA/CPU-based real-time simulation platform is presented in this paper, with a full-electric vehicle model implemented in a central processing unit (CPU) board and an electric drive model implemented in a field programmable gate arrays (FPGA) board. It has been a challenge to interface two models solved with two different processors. In this paper, one open-loop and three closed-loop interfaces are proposed. Real-time simulation results show that the best method is to transmit electric machine speed from the vehicle model to the electric derive model, with feedback electric machine torque calculated in FPGA. In addition, a virtual vehicle testing tool (CarMaker) is used when building the vehicle model, achieving more accurate modeling of vehicle subsystems. The presented platform can be used to verify advanced vehicle control functions during hardware-in-the-loop (HIL) testing. Vehicle anti-slip control is used as an example here. Finally, experiments were performed by connecting the real-time platform with a back-to-back electric machine test bench. Results of torque, rotor speed, and d&q axis currents are all in good agreement between simulations and experiments.
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| 9. |
- Mademlis, Georgios, 1992, et al.
(författare)
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Circulating Current Reduction in Common DC-Link Power-HIL for Drives using SVM with Zero-Sequence Compensation
- 2020
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Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2162-4704 .- 2577-1647. ; , s. 4673-4678
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Konferensbidrag (refereegranskat)abstract
- A new zero-sequence control technique is presented in this paper in order to eliminate the circulating current flowing in power hardware-in-the-loop test benches for electrical machine emulators. The machine emulator studied in this paper is made up of two three-phase inverters with an inductor connecting their ac-side. Both inverters share the same dc-link allowing circulating flow of the electric energy within this loop in order to emulate the operation of high power machine drives. Unfortunately, common-mode voltage is also freely developed within the loop and creates high circulating currents that act as a disturbance for the control of the inverters. Available control techniques have not managed to completely eliminate this current and common-mode filters are used additionally in order to solve the problem. The proposed zero-sequence control utilizes a modified version of the space vector modulation and reduces the circulating current amplitude up to 2.1% of the phase current, eliminating the need for hardware filters. Simulation results from Matlab/PLECS verify the effectiveness of the developed controller.
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| 10. |
- Pehrman, Daniel, 1988, et al.
(författare)
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Loss Reduction by Synchronous Rectification in a 50 kW SiC-based Inductive Power Transfer System
- 2020
-
Ingår i: IECON Proceedings (Industrial Electronics Conference). - 2577-1647 .- 2162-4704. ; 2020-October, s. 3907-3912
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Konferensbidrag (refereegranskat)abstract
- With development in wide band-gap semiconductors, such as silicon carbide (SiC), inductive power transfer (IPT) has become a promising technology for charging electric vehicles (EV). To meet fast charging demands by consumers, higher power levels in IPT is required. The power in IPT is usually limited by thermal stress due to losses at the vehicle side. Synchronous rectification is an efficient way to reduce losses compared to passive rectification. In this paper, the loss reduction accounted to synchronous rectification is quantitatively evaluated. The level of reductions varies depending on the load level, primary voltage, and constant current or constant voltage (CCCV) operation. The analytical results support the simulation results for various operating points. The loss profiles are studied for different dc-link voltages and duty cycles. An 800 V, 50 kW dual-active bridge test setup with series-series compensation is constructed and experiments are done for verification. The setup is arranged in a back-to-back configuration with a common dc-link. Experimental result shows that losses are reduced by up to 60 % on the receiving side with synchronous rectification. At rated operation the losses are reduced by 100 W in the secondary side inverter.
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