Evaluation of an in situ QAM‐based Power Line Communication system for lithium‐ion batteries

Abstract

Power Line Communication (PLC) is used to transmit high-fidelity data on internal cell characteristics from within instrumented cells to an external Battery Management System (BMS). Using PLC is beneficial, as it avoids the need for a complex and heavyweight wiring harness within a battery. The use of advanced modulation, such as Quadrature Amplitude Modulation (QAM), is considered here. The existing experimental results of lithium-ion cell impedance characteristics for frequencies of 100 kHz-200 MHz are exploited in order to create a realistic battery model. This model is used to determine the effectiveness and optimal properties of PLC with QAM, as a means of in situ battery communication for Battery Electric Vehicles (BEVs) in combination with a real-world dynamic drive profile. Simulations reveal that the performance of the PLC system is heavily dependent on the selected carrier frequency due to the significant changes in reactance and internal resistance of the lithium-ion cells tested. Furthermore, cells placed in parallel display a decreased performance compared with cells in series. The results highlight that the optimal carrier frequency for in situ QAM-based PLC for a lithium-ion battery system is 30 MHz, and that additional signal conditioning is required for 4-QAM and higher modulation orders.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A Smart Cell Monitoring System Based on Power Line Communication—Optimization of Instrumentation and Acquisition for Smart Battery Management

“…In general, frequency spectrum data is used to understand cell performance, however impedance data is not routinely reported above 10 kHz (for example for use in EIS, Electrochemical Impedance Spectroscopy) [28]. Several studies have been performed analyzing frequencies for PLC, starting at the low MHz range [29][30][31][32]. The channels available to transmit data via vehicular bus bars were studied by Sabir et al [30].…”

Impact of Battery State of Charge on In-Situ Power Line Communication Within an Intelligent Electric Vehicle

“…We have reported previously that when multiple Li-ion cells are connected within a battery configuration, the performance of an in-situ PLC system also changes [15]. As such, the configuration of the battery must be taken into account in addition to the changes in performance due to SoC of the cells within the battery.…”

DC Power Line Communication (PLC) on 868 MHz and 2.4 GHz Wired RF Transceivers

“…The state-of-the-art BMS technology is concentrated on power line communication (PLC) [12][13][14], wireless monitoring [15,16], and hybrid techniques combining both methods [17]. Providing a stable communication link with a local management system located in close proximity to the cell may result in faster charging for current Li-ion technology [18,19] or, alternatively, a temperature-controlled environment is required by the new fast-charging cells [20].…”