Stefan Zeltner

Smart Battery Cell Monitoring with Contactless Data Transmission

The market breakthrough of electric vehicles is mainly delayed by the still too high costs of the battery system. The smart battery cell monitoring presented in this article enables further cost reduction. It consists of battery cells integrating the monitoring electronics together with a data transfer interface for communicating in a bidirectional way with the battery management system. The data transfer interface presented in this paper is based on a differential contactless data transmission bus using galvanically isolated, capacitively coupled links to each single smart battery cell. Since neither galvanic contacts nor connectors are needed, the proposed concept provides simultaneously a very high level of reliability and robustness, and a highly cost-efficient manufacturing process, thus allowing a significant reduction of the final battery pack costs. This paper describes a possible implementation of such a differential contactless data transmission for monitoring and managing battery cells in electric vehicles.

A 22 kW On-board Charger for Automotive Applications Based on a Modular Design

In this paper a 22 kW on-board charger for electric or plug-in hybrid vehicles is proposed. To achieve high quantities of devices, a fully modular circuit and control structure is chosen. The circuit arrangement consists of three identical phase units (7.4 kW), which are comprised of two identical (3.7 kW) base units. The proposed charger is implemented and has a volume of 11.1 liters and a weight of 12 kg. The experimental result indicates an efficiency of more than 94 percent over the full battery voltage range at an input voltage of 230 Vac. The output voltage for full load and best efficiency varies from 315-395 V.

Power electronics for smart micro and nano grids controlled by a novel two-wire interface with integrated power and signal transfer

Power electronic systems comprising a high number of power converters on the load and energy supply side can be considered as smart micro or nano grids. Realizing such smart micro or nano grids means always the need of complex power electronics, consisting of electrically isolated and/or non-isolated, unidirectional and/or bidirectional AC/DC and/or DC/DC converters. Due to the requirement of different power converters a high number of active power switches, isolated gate drive supplies, isolated voltage and current measurements are necessary. In that case classic centralized control approaches are leading to very high efforts for wired connections. By using really intelligent power modules comprising novel two-wire interfaces with integrated power and signal transfer, control overhead by wired connections could be effectively reduced and safe galvanic isolation can be achieved.

A 3.7 kW on-board charger based on modular circuit design

In this paper a 3.7 kW On-board charger (OBC) for electric or plug-in hybrid vehicles is proposed. With regard to standardization, cost reduction and to increase the volume of produced devices, the OBC is derived from a fully modular circuit and control structure. The two-stage circuit arrangement consists of an isolated full bridge ZVS resonant converter and an interleaved boost converter for power factor correction (PFC). The proposed charger has a volume of less than 4 liters and a weight of 3 kg. The experimental result indicates an efficiency of more than 95 percent over the full battery voltage range at an input voltage of 230 Vac. The output voltage for full load and best efficiency varies from 315-395 V.

Methodisches Vorgehen zur integralen Auslegung von Produkt und Montage

Die Produktlebenszyklen werden durch den steigenden Wettbewerbsdruck stetig kurzer. Dies veranlasst Unternehmen, Produktinnovationen in immer geringeren Zeitabstanden auf den Markt zu bringen und Produktentwicklungszeiten zu verkurzen. Zusatzlich wirken sich erhohte Anforderungen bezuglich Produktzuverlassigkeit und -lebensdauer erschwerend aus. Um dieser Herausforderung zu begegnen ist eine enge Zusammenarbeit zwischen Entwicklung, Konstruktion, Fertigungsplanung und Prozessentwicklung unabdingbar, denn nur durch eine optimale Abstimmung von Konstruktion und Fertigungsprozess lassen sich die hohen Qualitatsanforderungen erfullen.