SCHEMATIC CAPTURE WITH CADENCE PSPICE - HERNITER

LINK
http://www.mediafire.com/file/k95lj4c628q53d9/HERNITER-PSPICE.pdf

A High Efficiency LLC Resonant Converter-based Li-ion Battery Charger with Adaptive Turn Ratio Variable Scheme Yeong-Jun Choi*, Hyeong-Gu Han-Dept. of Electrical and Biomedical Engineering, Hanyang University, Korea

A High Efficiency LLC Resonant Converter-based Li-ion Battery Charger with Adaptive Turn Ratio Variable Scheme Yeong-Jun Choi*, Hyeong-Gu Han*, See-Young Choi*, Sang-Il Kim* and Rae-Young Kim†

 Abstract – This paper proposes an LLC resonant converter based battery charger which utilizes an adaptive turn ratio scheme to achieve a wide output voltage range and high efficiency. The high frequency transformer of the LLC converter of the proposed strategy has an adaptively changed turn ratio through the auxiliary control circuit. As a result, an optimized converter design with high magnetizing inductance is possible, while minimizing conduction and turn-off losses and providing a regulated voltage gain to properly charge the lithium ion battery. For a step-by-step explanation, operational principle and optimal design considerations of the proposed converter are illustrated in detail. Finally, the effectiveness of the proposed strategy is verified through various experimental results and efficiency analysis based on prototype 300W Li-ion battery charger and battery pack. Keywords: LLC resonant converter, Battery charger, High efficiency, Adaptive turn ratio, Wide output voltage 1. Introduction Recently, various green transportations such as xEVs, E-bike, and E-scooter using batteries as a main power source, have expeditiously developed and penetrated the commercial marketplace. Generally, lithium-ion batteries are primarily used in such applications due to diverse reasons such as high energy densities, no memory effects and low self-discharge rates [1]. Meanwhile, the importance of the Li-ion battery charging system has also been increased to ensure safe and powerful use of the battery. Most charging systems employ a constant current-constant voltage (CC-CV) charging profile as displayed in Fig. 1 to prevent overcurrent and overcharge of the battery where the dashed line stands for a battery voltage Vbatt and the solid line stands for the battery charging current Ibatt [2]. As can be seen from the figure, the terminal voltage of the battery is widely varied from the cut-off voltage to the maximum charging voltage during the entire charging process; hence, Li-ion battery chargers should cover a wide output voltage range. LLC resonant converter is a promising high-efficiency battery charger candidate possessing several advantages [3-5]. The converter inherently achieves zero voltage switching (ZVS) of the primary side switches and soft commutation capability of semiconductor devices over the whole operational range. Therefore, the turn-on loss is small and the reverse recovery loss of the diode is reduced, so that a high switching frequency operation is possible and the power density of the entire system can be increased
Additionally the magnetic elements of the resonant tank can be integrated into a single transformer core, which isadvantageous in terms of cost.
However, the LLC resonant converter also possesses ahandicap as a battery charger: There is a trade-off in thedesign methodology to achieving high efficiency and meeting wide output voltage variations to cover wide variations in battery terminal voltage. To achieve a wide output voltage range, the LLC resonant converter need tooperate at a frequency lower than the resonant frequency.
However, such operation decreases efficiency due to the presence of a large circulating current. Moreover, a small magnetizing inductance of the resonant tank is usually required; therefore, efficiency became worse due to an excessive turn-off loss and magnetizing current. Hence, the optimal design of an LLC resonant is realized to be adelicate process [6].
To overcome this problem, several studies have been performed [7-15]. One solution is to develop a design method for resonant tanks to meet a given battery voltage and efficiency specification. [7-12]. However, these studiesonly reveal the inherent trade-off relationship limitation that cannot naturally be overcome. In the literature, a strategy of using auxiliary windings was proposed to realize a wide output voltage [13]. However, since this method was proposed for hold-up compensation, so there is no focus on maintaining the ZVS condition, and it is
difficult to apply it to a battery charger. Some other researches discussed solutions for high power applications such as 3.3kW or 6.6kW [14, 15]. The main concept of these studies is to integrate the many advantages of two or more DC-DC converters with topology modification.
However, it is impossible to apply results of theseresearches directly for low power applications below 500W.

LINK WEB
http://www.jeet.or.kr/LTKPSWeb/pub/pubfpfile.aspx?ppseq=1943

Compact DC-AC SiC Inverter for High Ambient Temperatures in Hybrid Electric Vehicles- ETH Zurich Power Electronic Systems Laboratory

Compact DC-AC SiC Inverter for High Ambient Temperatures in Hybrid Electric Vehicles
 Power electronic converters are key components of Hybrid Electric Vehicles, which are in the core focus of the Research and Development activities of the automotive industry. Today’s converters feature Silicon power semiconductors with a junction temperature limit between 150 °C and 175 °C and thus their operating ambient temperature range is limited to values typically well below 80 °C. This implies undesired restrictions regarding cooling circuit requirements or the placement of the converter due to the ambient air temperature level in case of air-cooled converters.Silicon Carbide (SiC) power semiconductor switches allow to increase the junction temperature beyond 175 °C and thus to overcome the above mentioned restrictions. In this research project, an ambient-air-cooled, high power density SiC inverter system for an ambient air temperature level of 120 °C is investigated. In order to be able to fully utilize the semiconductors, the converter is designed for an optimum junction temperature of 250 °C. A high switching frequency of 50 kHz keeps volume and weight of passive components low and covers a broad range of output frequencies suitable even for driving high-speed electrical machines. It is made sure that the individual devices are operated within their specified temperature ranges by carefully choosing the component placing taking needs from an electrical point of view into account and by active Peltier cooling of the components. Some components, such as high performance fans for the air-cooling system, are currently not available on the market in the required temperature range and thus are developed as an additional part of this project. All obtained results are experimentally validated on a test high speed test bench with a 10 kW permanent magnet synchronous machine and an induction machine rotating up to 30’000 rpm.
 Power Electronics Systems Laboratory DC-AC Converters
 Dr. Benjamin Wrzecionko  Contact ETH Zurich Power Electronic Systems Laboratory Physikstrasse 3 ETL H23 8092 Zurich Switzerland

LINK
https://www.ethz.ch/content/specialinterest/itet/power-electronic-systems-lab/en/research/research-and-thesis-projects/dc-ac-converters/DC-AC-Converters-1.html

WIRELESS CHARGING OF ELECTRIC VEHICLES Omer C. Onar, Steven Campbell, Larry Seiber, Cliff White Power Electronics and Electric Machinery Group (PEEM) Electrical and Electronics Systems Research Division (EESR)

Oak Ridge National Laboratory Wireless Charging of Electric Vehicles – CRADA Report WIRELESS CHARGING OF ELECTRIC VEHICLES 

Omer C. Onar, Steven Campbell, Larry Seiber, Cliff White, Madhu Chinthavali, Lixin Tang, Paul Chambon, and Burak Ozpineci Power Electronics and Electric Machinery Group (PEEM) Electrical and Electronics Systems Research Division (EESR)


1. Abstract Wireless power transfer (WPT) is a paradigm shift in electric-vehicle (EV) charging that offers the consumer an autonomous, safe, and convenient option to conductive charging and its attendant need for cables. With WPT, charging process can be fully automated due to the vehicle and grid side radio communication systems, and is non-contacting; therefore issues with leakage currents, ground faults, and touch potentials do not exist. It also eliminates the need for touching the heavy, bulky, dirty cables and plugs. It eliminates the fear of forgetting to plug-in and running out of charge the following day and eliminates the tripping hazards in public parking lots and in highly populated areas such as shopping malls, recreational areas, parking buildings, etc. Furthermore, the high-frequency magnetic fields employed in power transfer across a large air gap are focused and shielded, so that fringe fields (i.e., magnetic leakage/stray fields) attenuate rapidly over a transition region to levels well below limits set by international standards for the public zone (which starts at the perimeter of the vehicle and includes the passenger cabin). Oak Ridge National Laboratory’s approach to WPT charging places strong emphasis on radio communications in the power regulation feedback channel augmented with software control algorithms. The over-arching goal for WPT is minimization of vehicle on-board complexity by keeping the secondary side content confined to coil tuning, rectification, filtering, and interfacing to the regenerative energy-storage system (RESS). This report summarizes the CRADA work between the Oak Ridge National Laboratory and the Toyota Research Institute of North America, Toyota Motor Engineering and Manufacturing North America (TEMA) on the wireless charging of electric vehicles which was funded by Department of Energy under DE-FOA-000667. In this project, ORNL is the lead agency and Toyota TEMA is one of the major partners. Over the course of the project, ORNL and Toyota TEMA worked closely on the vehicle integration plans, compatibility, and the interoperability of the wireless charging technology developed by ORNL for the vehicles manufactured by Toyota. These vehicles include a Toyota Prius Plug-in Hybrid electric vehicle, a Scion iQ electric vehicle, and two Toyota RAV4 electric vehicles. 2. Statement of Objectives The main objective of this project is to coordinate multi-party team for the design, development, and fabrication of WPT grid side unit (GSU), coupling coils, and the vehicle side power conditioning units. The GSU includes the active front-end rectifier with power factor correction (PFC), high-frequency power inverter, and the high-frequency isolation transformer whereas vehicle side unit includes a resonant tuning capacitor, a bridge rectifier, a filter circuit, and the additional relays and contactors that are used to timely respond to the charging request or to comply with the charging protocols that a vehicle may have (CHAdeMO, J1772, or direct battery connection). The objective of this work is to demonstrate a fully automated charging process including the alignment, start charging, stop charging, and the emergency and orderly shutdown procedures while meeting at least 6.6kW power transfer over 160mm magnetic airgap while exceeding an overall (end-to-end) efficiency of 85%. After integrating ORNL developed WPT technology into demonstration vehicles, an additional objective was to validate the system operation in an independent testing laboratory (Idaho National Laboratory) for field testing of this technology which will assist in system improvements and standards development. In this project, Evatran was the commercialization partner and under ORNL guidance worked on cost and component optimization and fabrication of GSUs and also the primary and secondary coils. Evatran also worked on vehicle integrations in coordination with ORNL and other partners. Clemson University ICAR Center was the demonstration site for phase #2 deliverables of the project. Clemson University, in collaboration with Cisco Systems, also supported the radio communications developments and radio integrations to the vehicles and the WPT equipment on the vehicles. Finally, Toyota Motor Corporation is the vehicle OEM partner provided the vehicles and collaborated with ORNL on the vehicle integrations. One last objective of this project was to demonstrate in-motion wireless charging on Toyota RAV4 vehicles to prove feasibility and collect data.

LINK FULL PAPER
https://info.ornl.gov/sites/publications/files/Pub68349.pdf

SEMIKRON Innovation Award 2018 & Young Engineer Award 2018

Press release
SEMIKRON Foundation and ECPE honour Mr. Stefan Matlok with the Innovation Award 2018 and Mr. Diogo Varajão for his work with the Young Engineer Award
Stuttgart, Germany, March 22nd 2018
The jury has decided to give the SEMIKRON Innovation Award 2018 to Stefan Matlok from Fraunhofer IISB in Erlangen, Germany for his outstanding work on ‘Zero Overvoltage Switching "ZOS"’
Abstract:
In power electronics turning off an electrical path is causing trouble by parasitic inductance leading to oscillations and voltage overshoot. The novel Zero Overvoltage Switching (ZOS) method offers the possibility to unleash unlimited switching speed in real-world applications without overvoltage on the semiconductors. Moreover, in best case, it is even avoiding any subsequent parasitic oscillation. The idea is to use the intrinsic parasitic inductances and parasitic capacities to build up a resonant circuit. The turn off event excites the resonant circuit and the free-wheeling diode stops it automatically after half a period, e.g. after a view nanoseconds. These resonant parasitic elements are thereby utilized to switch off a fixed current in a nearly lossless, overvoltage- and EMI compliant way. By designing the circuit and parasitics properly, there is no extra component necessary as parasitic inductance is now functional part of the topology.
The SEMIKRON Young Engineer Award 2018 is given to Mr Diogo Varajão
from AddVolt AS in Porto, Portugal for his contributions on ‘ACDC CUBE: Single-stage Bidirectional and Isolated AC-DC Matrix Converter for Battery Energy Storage Systems’
Abstract:
The ACDC CUBE technology consists in a new modulation and control strategy for the high-frequency link matrix converter. The matrix converter is a key element of the system, since it performs a direct AC to AC conversion between the grid and the power transformer, dispensing the traditional DC-link capacitors. Hence, the circuit volume and weight are reduced and a longer service life is expected when compared with the existing technical solutions. The innovation was validated through a prototype tested in the laboratory. Experimental results demonstrate the capability to control the grid currents in the synchronous reference frame in order to provide services for the grid operator. Additionally, the battery current is well regulated with small ripple which makes this converter appropriate for battery charging of EVs and energy storage applications.
Photo: (f. l. to r.) Prof. Leo Lorenz (ECPE), Stefan Matlok, Diogo Varajão, Peter Beckedahl (SEMIKRON)
About the SEMIKRON Foundation:
The SEMIKRON Foundation was founded on December 4, 2010, by owners of the SEMIKRON Group. Equal founders are the daughters of Peter Martin, the SEMIKRON owner and managing director of many years, who passed away in 2008. With the founding act, the founders intended to live up to their responsibility being the owners of a family-owned medium industry business and to contribute to their company’s “Corporate Social Responsibility”.
The purpose of the SEMIKRON Foundation is to bundle and extend the charitable activities operated by the owners of the SEMIKRON Group. In particular, the humanitarian projects initiated by Mr. Peter Martin, and supported by the Mali Martin Care e.V. charity are to be continued. These projects support children and people in need all over the world. Over the past 10 years, Mali Martin Care e.V. has donated more than one million Euro to humanitarian projects for children and young adults, mostly in Brazil (projects “Centro Social” and “Lar do Menor”). In addition, the foundation supports research projects and innovations in the field of power electronics. For more information, please visit: www.semikron-stiftung.com.
Contact:
Board: Rechtsanwalt Dr. Felix Hechtel
SEMIKRON-Stiftung
Sigmundstraße 200
90431 Nürnberg
Tel: 0911/6559-0
E-Mail: felix.hechtel@semikron-stiftung.de
Press contact:
Werner Dorbath
SEMIKRON-Stiftung
Sigmundstr. 200
90431 Nürnberg
Tel: +49-(0) 911-6559-217
Mobile: 0049/(0) 176 30086217
werner.dorbath@semikron.com
Contact:
ECPE European Center for Power Electronics e.V.
Bayerischer Cluster Leistungselektronik
Dipl.-Phys. Thomas Harder, Geschäftsstellenleiter und Clustergeschäftsführer Landgrabenstraße 94, D-90443 Nürnberg Tel: 0911 / 81 02 88-11 Fax: 0911 / 81 02 88-28 E-Mail: thomas.harder@ecpe.org

LINK ORIGINAL:
https://www.semikron.com/about-semikron/news-press/detail/innovation-award-2018-young-engineer-award-2018.html