Lithium ion batteries are essentially superior to conventional batteries due to their energy density and their small volume as well as due to their better cycle behaviour. In particular LiFePO4 cells of a new design with large capacity are very appropriate for the use in hybrid vehicles. For a reliable and efficient operation, the energy management of hybrid vehicles requires extensive and precise information about the battery status. The detection and the monitoring of status data on the basis of measured values is the main task of the battery management, apart from the communication with the energy management. The present article describes such a battery management system, regarding the fundamental difficulties in the registration and evaluation of lithium ion battery status data. The battery management system has a modular structure. The smallest module controls a maximum of 10 cells. It monitors the cell voltages, the module temperatures and some safety parameters. The modules are connected as 'slaves' to a 'master'. The master measures the battery current, calculates the battery parameters of loading, power and ageing status and communicates to the electronic system of the vehicle via a CAN interface. The conversion of a Toyota Prius II is shown as an exemplary application. This is using a modular battery management system in a plug-in hybrid with increased cruising range and the integration of the battery management system into the control device network of the Prius II. For this, the previous NiMH battery (201 V/6,5 Ah) was replaced by 63 LiFePO4 cells from the manufacturer Gaia Akkumulatorenwerke GmbH, having 33Ah each. They offer the five-fold energy with double volume and approximately the same voltage. This allows more than 50 km of purely electrical driving with a speed of up to 55 km/h (beyond this, the combustion engine is activated automatically). Charging is performed with the installed combustion/generator combination, or with an additionally installed charging device. Depending on the charging device, charging times of less than 2 h can be achieved with a mains power outlet.
Modular battery management system for lithium ion batteries for plug-in hybrid vehicles
Modulares Batteriemanagementsystem für Lithiumionenbatterien zum Einsatz in Plug-in-Hybridfahrzeugen
2008
26 Seiten, 13 Bilder, 1 Tabelle, 18 Quellen
Conference paper
English
Hybridfahrzeug , galvanische Batterie , Modulbauweise , Lithiumionenbatterie , Energiedichte , elektrolytische Zelle , Monitoring , Energiemanagement , Betriebszustand , elektrische Spannung , Interface (Schnittstelle) , Steuerungsgerät , Elektroantrieb , Fahrgeschwindigkeit , Batterieaufladung , NiMH-Batterie , Batteriemanagement
Modular battery management system for lithium in batteries for plug-in hybrid vehicles
Automotive engineering | 2008
|Modular battery management system for lithium ion batteries for plug-in hybrid vehicles
Automotive engineering | 2008
|