The battery is a fundamental component of electric vehicles, which represent a step forward towards sustainable mobility. Lithium chemistry is now acknowledged as the technology of choice for energy storage in electric vehicles. However, several research points are still open. They include the best choice of the cell materials and the development of electronic circuits and algorithms for a more effective battery utilization. This paper initially reviews the most interesting modeling approaches for predicting the battery performance and discusses the demanding requirements and standards that apply to ICs and systems for battery management. Then, a general and flexible architecture for battery management implementation and the main techniques for state-of-charge estimation and charge balancing are reported. Finally, we describe the design and implementation of an innovative BMS, which incorporates an almost fully-integrated active charge equalizer.
We experimentally investigate the benefits of a new optical pulse coding technique for long-range, meter and submeter scale Raman-based distributed temperature sensing on standard single-mode optical fibers. The proposed scheme combines a low-repetition-rate quasi-periodic pulse coding technique with the use of standard high-power fiber lasers operating at , allowing for what we believe is the first long-range distributed temperature measurement over single-mode fibers (SMFs). We have achieved spatial resolution over of SMF, attaining temperature resolution within measurement time.
9 October 2012 in IEEE Transactions on Industrial Informatics
The charge stored in series-connected lithium batteries needs to be well equalized between the elements of the series. We present here an innovative lithium-battery cell-to-cell active equalizer capable of moving charge between series-connected cells using a super-capacitor as an energy tank. The system temporarily stores the charge drawn from a cell in the super-capacitor, then the charge is moved into another cell without wasting energy as it happens in passive equalization. The architecture of the system which employs a digitally-controlled switching converter is compared with the state of the art, then fully investigated, together with the methodology used in its design. The performance of the system is described by presenting and discussing the experimental results of laboratory tests. The most innovative and attractive aspect of the proposed system is its very high efficiency, which is over 90%.
21 August 2009 in IEEE Transactions on Industrial Electronics
This paper presents the design, implementation, and validation of a FlexRay transceiver and a SpaceWire (SpW) router and interface, which constitute the main hardware building blocks of the two in-vehicle communication standards. The FlexRay protocol features data rates up to 10 Mb/s and time- and event-triggered transmissions, along with scalable fault-tolerance support, and it is expected to become the standard network for X-by-wire and active safety automotive systems. However, collision avoidance and driver-assistance applications based on camera/radar sensors require data rates up to hundreds of megabits per second as well as fault tolerance, features that can hardly be covered by current or expected automotive standards. In this scenario, a promising technology seems to be the new SpW protocol, currently used in avionics and aerospace.
9 January 2014 in IEEE Transactions on Industrial Informatics
This paper presents a novel charge equalization technique seamlessly integrated into a modular Battery Management System (BMS) for lithium-ion (Li-ion) batteries. The charge equalizer is a crucial element for an effective use of a Li-ion battery consisting of many series-connected cells. We describe a fully distributed charge equalizer based on a circular balancing bus, which outperforms other recently published approaches. Its safety requirements have formally been verified using a model checker, showing that formal methods and, in particular, the Symbolic Analysis Laboratory environment, can be effective to verify the safety requirements of a BMS.