1-day Workshop on ‘Health-conscious Fast Charging Strategies & Battery Management Systems For Electrified Autonomous Transportation’

Continuing with the belief that technical education shouldn’t be limited to classroom sessions, IEEE SB TKMCE Unit has conducted a talk on the topic – ‘Health-conscious Fast Charging Strategies and Battery Management Systems for Electrified Autonomous Transportation’ at TKM College of Engineering, Kollam on 5th of August 2019. It had been presented by Prof. Sheldon S. Williamson associated with the Ontario Tech University, Canada who holds the prestigious NSERC Canada Research Chair position in electric energy storage systems for transportation electrification. About 59 undergraduate students from various colleges took part in the workshop among which 10 of them were IAS members. The session began at 9:30 am and longed till 3:30 pm. The technical talk was split into 4 sessions as pre-planned by Prof. Sheldon. 

Session 1: Smart Power Electronics Based Active Battery Energy Management Systems for Electric Transportation

Enhancing the life of Lithium-ion (Li-ion) battery packs has been the topic of much interest in the e-transportation industry. In this session, the role of on-board cell voltage balancing (with temperature rise considerations) of Li-ion batteries had been highlighted. This is a very important design aspect, which directly affects cost, calendar life, state-of-charge, and state-of-health. The design and implementation of a novel, reduced-parts DC/DC converter for battery cell-voltage-equalization were discussed. It also introduced a closed-loop cell charge balancing technique that uses instantaneous cell voltage and/or temperature rise (ΔT) as a control parameter.

The starting module of the talk stood up as a great start as the mode of presentation was quite engaging. He was keen to share his knowledge and the students were equally eager to listen to him. 

Session 2: Novel Power Converters for DC Fast Charging

Presently available level 3 DC fast charging systems had been reviewed, followed by a brief description and evaluation of DC fast-charging infrastructure. Different power converter topologies and viable configurations were presented, compared, and evaluated. These topologies will be compared based on their power levels, efficiency, cost, and specifications. The possibility of employing a 3-phase, 3-switch (TPTS) converter as a single-stage charger for DC fast charging was introduced. A new modulation technique for controlling a TPTS converter was introduced further. Experimental verification and test results of the designed converter/charger prototype were presented.

Prof. Sheldon found himself facing a volley of questions from the students as everyone in the hall suddenly turned out to their inquisitive best. The calm and composed person he is, the doubts began to turn out as things of past!

Session 3: Integrated PV/Smart-grid Based Charging Applications

This session introduced both home and public charging interface designs from a power electronic intensive solution perspective. Several grid-connected as well as PV/grid interface topologies for EV charging were presented. The modeling, sizing, design, and implementation of a novel high-efficiency, single-stage PV/grid/EV charging infrastructure was also presented. The designed charging infrastructure supported both Levels 1 and 2 DC charging. The students identified it as a new concept for charging which is vital due to the inevitable need for harnessing renewable energy sources.

Session 4: High-Efficiency, Wireless Fast Charging Concepts and Methodologies

The concluding part of the talk focussed on introducing advanced power electronics solutions for rapid charging using wireless power transfer. Both inductive power transfer (IPT) and capacitive power transfer (CPT) were introduced. The major market for IPT-based wireless charging is the mass transit industry, such as electric trains, buses, and trams, in the range of 100-250 kW, while both IPT and CPT could be used for charging small utility-grade EVs (golf carts), in smaller sizes of 1.0 kW. Critical issues such as IPT coil design, CPT dielectric medium/transfer plate designs, and converter topologies were discussed. Detailed results of finite element analysis (FEA) designs for coils were presented. The design of charger topologies on the secondary side were also be discussed. The challenge as proclaimed by the presenter is to come up with 1-stage power conversion, including high-frequency (HF) AC/DC rectification and DC/DC charger functionalities, with conversion efficiencies of  98%.

The technical talk as a whole had been unanimously viewed as a fruitful one in invoking a scientific temper in one and all attending it.