Electric Vehicles

Many EV subsystems are sensitive to the battery performance and behavior throughout the various modes of operation. The drivetrain, inverters, environmental and entertainment controls, ECM and many ECUs all interact with the battery. Subsystem behavior may be effected by the battery’s SoC estimation, SoH, drive cycles, imbalance, ageing, contactor control, alarms and diagnostic trouble codes. These behaviors are difficult, expensive, and often dangerous to replicate in a test lab or track using actual EV batteries.

In this presentation, some considerations with new EV programs are discussed followed by the top 5 (really 7) challenges with developing and testing the battery management system (BMS). A few product demonstration slides are included as well as several practical BMS test solutions.

Presented by Peter Blume and Grant Gothing at the Charged Virtual Conference on EV Engineering on September 1, 2020
 

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Hardware-In-the-Loop (HIL) testing is a powerful approach to validating many complex automotive ECUs, including the battery management system (BMS). In fact, BMS HIL testing can dramatically accelerate the battery and electrical systems development for new EV programs, while optimizing the safety, reliability, and performance. But what comprises a typical BMS HIL Test System, and how do they work?

Many EV suppliers utilize inefficient approaches for testing the vehicle’s electronic subsystems, including the battery management system (BMS), cell monitors, safety interlocks, and charging systems. For example, use of either live li-ion cells or conventional power supplies and loads produces unsatisfactory results. Limitations with these approaches include safety, repeatability, efficiency and test coverage. Use of traditional, vendor-defined test systems limit the flexibility and scalability of the system.

Battery management system (BMS) testing has different challenges at different phases of the development lifecycle, from hardware prototype, embedded software development, regression testing, validation, to PCBA manufacturing test. A common requirement is simulating the battery in a safe, efficient, and repeatable manner, including charging, discharging, cell balancing, SOx, as well as simulating common battery faults such as over-voltage, over-current, over-temperature, short-circuit, and open circuit.

Hardware-in-the-loop test is the standard approach to validating the design of xEV systems including the battery management system electronics and firmware. Explore an open systems architecture approach to HIL test system implementation including the overall benefits demonstrated by market-leading xEV companies like LG Chem and Jaguar Land Rover.

Presented by Steven Hoenig at NIWeek in Austin, TX on May 23, 2017

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Presented by Peter Blume at the Automotive Testing Expo 2016 in Novi, MI

Hardware-In-the-Loop (HIL) testing is an essential approach for validating the hardware and firmware of an automotive ECU, including the battery management system (BMS) electronics of hybrid and electric vehicles (xEVs). An HIL Simulator is used to simulate the xEV battery including cell chemistry, drive cycles, and numerous fault conditions; without the hazards of real batteries, or the cost of prototype vehicles and track time.