Electrical measurement technology specialist LEM has launched a new SMU (single monitoring unit) family designed to work with all types of EV technologies – FHEVs, PHEVs and BEVs.
The new modular SMU meets the needs of designers of automotive battery management systems (BMS) with the aim to extend the range as far as possible. The SMU continuously monitors vehicle parameters such as battery performance and safety systems. It also identifies anomalies and support diagnostics, which improves vehicle efficiency and ensures compliance with regulations.
The high-performance sensor has been designed to accommodate the need for compact components that enable a reduction in the weight of EVs. The SMU measures just 29.1mm (H) x 35.5mm (W) x 49.9mm (L) while the busbar thickness is 2mm to 3mm compatible. The integrated busbar has been designed to accommodate a range of different busbar dimensions.
The key to optimal EV range is accurate state of charge (SOC) estimation – precisely determining the remaining battery capacity. Accurate SOC estimation helps optimize battery life and prevent unexpected power loss, while reducing range anxiety and delivering efficient energy management.
The SMU is a Hall effect technology sensor, open loop configuration using the latest LEM9 Application-Specific Integrated Circuit (ASIC). Designed by LEM to add intelligence at the Battery Disconnect Unit (BDU) level, the ASIC also considers environmental factors while ensuring accurate sensor performance.
The sensor features improved accuracy using software algorithms that can correct or adjust measurement data to account for distortions or errors.
Other features include digital calibration, improved offset/sensitivity calibration, and diagnostic warnings as under- or over-voltage. Additionally, malfunction can be avoided by a dedicated safe state mode and the sensor’s internal microcontroller includes a built-in algorithm to correct for any magnetic offset, ensuring more accurate readings.
LEM’s new SMU family is compliant with functional safety conditions. This means it satisfies the stringent Automotive Safety Integrity Level (ASIL) requirements built into the ISO 26262 standard for functional safety in vehicles. The first version to enter the market is ASIL B ready with the possibility to extend it to ASIL C.
Jérémie Piro, global product manager BMS at LEM, said, “It’s widely understood that the EV industry is continually looking to maximize driving range. BMS designers will welcome a new sensor that is not just compact but also ensures accurate SOC estimation, which are the two main factors. We are very excited that the new SMU family will bring previously unseen performance levels to the FHEV, PHEV and BEV sectors.”
