Investigating and modeling the transmission channel of a prismatic lithium-ion cell and module for powerline communication

- Interaction between electrodes, poles and housing of a cell is verified for RF.
- Impedance of a battery depends on housing size and separation distance.
- High frequency model of a single cell strongly depends on mechanical structure.
- Scalable high frequency model for batteries is proposed.
- Parallel coupling method is better than serial method for PLC application in BMS.

Current lithium-ion battery management systems require a huge amount of connecting units for monitoring and controlling single cells. A sophisticated way of simplifying a complex wiring architecture is the use of a powerline communication system. By this approach the existing powerline is simultaneously used for data transmission. However, a thorough understanding of the channel characteristics in the high frequency range (1-110 MHz) is necessary to be able to design and implement such a system. This work deals with the characterization of the powerline channel of <10 Ah prismatic hard case Lithium-Ion cells and 10 cell modules with special respect to the interaction between single cells using impedance measurements. Based on the obtained knowledge, a circuit-based model of the transfer channel has been designed, allowing to estimate the behavior of larger battery systems. The model was also used to simulate different coupling methods to transmit and receive signals to the powerline.