Summary
- LEM introduced a new SMU sensor range for accurate SOC estimation in electric and hybrid vehicles
- The SMU continuously monitors battery performance and safety systems, identifying anomalies and supporting diagnostics
- The compact unit is compatible with a range of busbar dimensions and uses the latest LEM9 ASIC for accurate measurements
- Features including digital calibration, E2E protection, and improved offset/sensitivity calibration are included
- The new SMU family is compliant with ASIL requirements in the ISO 26262 standard for functional safety in vehicles
Article
LEM, an electrical measurement technology company, has recently introduced a new single monitoring unit (SMU) sensor range aimed at providing accurate state of charge (SOC) estimation for electric and hybrid vehicle technologies. The SMU sensor continuously monitors vehicle parameters such as battery performance and safety systems, identifying anomalies and supporting diagnostics to enhance vehicle efficiency and compliance with regulations. The compact unit, measuring 29.1mm x 35.5 mm x 49.9 mm, is designed to accommodate a range of busbar dimensions with a thickness of 2 mm to 3 mm, improving accuracy.
Equipped with the latest LEM9 application-specific integrated circuit (ASIC), the SMU sensor is capable of measuring environmental factors and ensuring accurate sensor performance at the Battery Disconnect Unit (BDU) level. It features built-in software algorithms that can correct or adjust measurement data to eliminate distortions or errors caused by mechanical stresses, enabling accuracy up to 1% up to 1300 A and <1.7% up to 1500 A. Additional features include digital calibration, end-to-end (E2E) protection, improved offset/sensitivity calibration, and diagnostic warnings for under-voltage or overvoltage issues.
The SMU sensor incorporates a dedicated safe state mode to prevent malfunctions in case of sensitivity and offset drift, temperature measurement errors, or memory errors. Its internal microcontroller includes a built-in algorithm to correct magnetic offsets, ensuring more accurate and reliable sensor readings by eliminating errors related to residual magnetism. With high isolation levels capable of withstanding voltage differences exceeding 800 V, the sensor prevents electrical interference or damage, making it suitable for use in electric and hybrid vehicles.
This new SMU sensor family from LEM is compliant with the Automotive Safety Integrity Level (ASIL) requirements outlined in the ISO 26262 standard for functional safety in vehicles. By meeting these standards, the sensors are designed to provide reliable and accurate state of charge estimations for electric and hybrid vehicle technologies while ensuring compliance with safety regulations. The sensor range offers a compact design, advanced measurement capabilities, and built-in features such as digital calibration and diagnostic warnings, making it a valuable addition to the electric and hybrid vehicle industry.
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