Ensuring a reliable, efficient and safe battery management system with model-based design

The automotive industry faces major challenges in developing a battery management system (BMS) for electric vehicles (EVs), including battery safety, lifespan optimization and energy efficiency.

A BMS must enhance vehicle range, ensure battery cell balance and guarantee safe operation against hazards like overcharging and short circuits. Managing battery aging and thermal regulation are critical, requiring advanced state-of-x (SoX) estimations for accurate management. Integrating AUTomotive Open System ARchitecture (AUTOSAR) ensures standardized, modular BMS software development, facilitating easier updates and compliance. Leveraging model-based design (MBD) for a BMS offers improved design accuracy, collaboration, faster development, cost reduction and robust quality. Virtual testing with MBD allows early detection of issues, comprehensive and iterative testing and effective risk mitigation, leading to reliable and efficient BMS development.

Simcenter Engineering and Consulting services offer a complete service from our experts for implementing a comprehensive BMS software solution using industry best practices and MBD. Benefiting from Simcenter Simulation and Test solutions and other tools from the Siemens Xcelerator ecosystem, our consultants help you implement advanced BMS algorithms, integrate and implement AUTOSAR and deploy a methodology and framework to automate the verification testing of the BMS software.

BMS software architecture

BMS software architecture is a complex, multilayered framework, ensuring efficient and safe operation of battery packs in EVs. The key modules include:

• Data acquisition: collects real-time data from sensors monitoring voltage, current, temperature and other critical parameters
• SoX estimation: calculates the state of charger (SoC), state of health (SoH) and state of power (SoP) using advanced algorithms and machine learning (ML) techniques
• Cell balancing: Ensures uniform voltage across all battery cells to maximize efficiency and lifespan via passive or active balancing techniques
• Thermal management: Controls heating and cooling systems to maintain optimal temperature, preventing thermal runaway and ensuring consistent performance
• Safety management: Monitors for potential hazards like overcharging, deep discharging and short circuits, implementing fail-safe mechanisms to protect the battery and vehicle

Addressing BMS design challenges

Our engineers provide best practices for developing and implementing advanced algorithms to meet a BMS’ safety, reliability, state estimation, and thermal management needs.

Here are a few examples:

• Vehicle range and performance: automotive companies must optimize a BMS for vehicle range and enhance performance. This involves precise energy management and accurate SoC estimations to maximize battery capacity without over-discharge. Additionally, efficient algorithms are required to manage power distribution, reduce energy waste and adapt to driving conditions
• Battery cell balancing: it ensures uniform voltage across all cells, preventing reduced efficiency, diminished lifespan and safety hazards. Developing sophisticated balancing techniques (passive and active) is essential for optimal battery performance and longevity
• Safe operation: ensuring safe battery operation is crucial. A BMS must monitor for hazards such as overcharging, deep discharging, short circuits and thermal runaway. Advanced safety protocols and real-time diagnostics are essential for risk detection and mitigation, ensuring passenger and vehicle safety
• Battery aging: battery aging affects performance and reliability. BMS algorithms must predict and adapt to aging processes, managing capacity fade and internal resistance increase. Accurate aging models and adaptive management strategies maintain performance over the battery’s lifecycle, preventing premature failure
• Thermal management: effective thermal management prevents overheating and ensures optimal performance. A BMS must regulate temperatures using cooling and heating systems, especially under extreme conditions. Efficient thermal management extends battery life, improves safety and maintains performance by preventing thermal runaway and ensuring uniform temperature distribution
• SoX estimations: SoX estimations, including SoC, SoH and SoP, are vital for accurate battery management. Developing precise estimation models requires complex algorithms and real-time data analysis. Integrating advanced sensors and ML techniques ensures accurate SoX readings, efficient energy management and predictive maintenance

AUTOSAR integration

Integrating AUTOSAR provides a standardized platform for developing and integrating automotive software components, ensuring interoperability, scalability and reusability across BMS implementations. It defines a layered architecture, including basic software (BSW), runtime environment (RTE) and application layer hosting BMS-specific functionalities such as SoX estimation, cell balancing and thermal management. Leveraging AUTOSAR streamlines BMS development, ensures compliance with industry standards and facilitates integrating new features and technologies.

Using the Polarion portfolio, Simcenter Engineering and Consulting services streamline developing BMS software architecture to provide the necessary orchestration to provide full traceability between functional safety and performance requirements and their associated verification tests. Leveraging Polarion also provides the necessary traces to virtual models used for model-in-the-loop (MIL) and hardware-in-the-loop (HIL) testing, as well as traceability to the software implemented to meet the requirements.

Simcenter and Polarion are part of the Siemens Xcelerator business platform of software and hardware.

Leveraging model-based design (MBD) in BMS design

Leveraging MBD for BMS software design enhances efficiency, reliability and innovation. MBD uses mathematical and visual models to design, simulate and verify complex systems. MBD presents several benefits:

• Improved design accuracy and efficiency: using MBD allows engineers to create accurate mathematical models of the BMS and simulate its behavior under various conditions. This helps identify and resolve issues early, reducing the need for physical prototypes and extensive testing
• Enhanced collaboration: leveraging MBD provides a common framework for various teams (software, hardware and systems engineering) to collaborate seamlessly. Using unified models facilitates better communication and understanding among team members
• Accelerated development cycle: using MBD significantly shortens the development cycle. The ability to simulate and test the BMS design in a virtual environment accelerates validation and verification processes
• Reduced cost: using MBD reduces development costs by minimizing reliance on physical prototypes and extensive real-world testing. Early detection of design flaws and optimization using simulation prevents costly redesigns and iterations
• Improved quality and reliability: leveraging MBD enables thorough testing and validation of the BMS under a wide range of operating conditions, ensuring robust and reliable performance
• Advanced feature facilitation: with MBD, integrate advanced features such as ML algorithms for predictive maintenance, adaptive control strategies for energy management and real-time diagnostics
• Ensured regulatory compliance: using MBD helps ensure the BMS design complies with industry regulations and standards. The ability to simulate and document the design process provides clear evidence of compliance, simplifying the certification process

Verifying BMS software using 1D MBD simulations

Our experts use MBD to accelerate developing and verifying BMS software and battery pack design prior to the availability of physical software. Leveraging MBD allows companies to shift left and reduce cost and time-to-market. It also enhances virtual testing with simulation in BMS software development, creating detailed mathematical models to evaluate performance, safety and reliability under various conditions.

The Simcenter Engineering and Consulting services benefit from the multidomain models included into Simcenter Amesim, including battery cells, power electronic components and thermal management systems. To cope with real-time constraints, models can be simplified while preserving physical relevance, through a continuous process, streamlined by powerful model simplification tools.

Simcenter Amesim supports the classical control development process using MiL, software-in-the-loop (SiL) and HiL techniques.

• MiL: a model of the BMS control (usually in Matlab/Simulink) can be interfaced with a model of the battery and related subsystems, in a co-simulation model, to rapidly validate the control architecture
• SiL: when the C-code of the BMS exists, it can be coupled again with a multiphysics system model in co-simulation model, to start also the calibration process of the algorithm parameters
• HiL: here, the real BMS exists and is validated against a model of the battery running on real-time hardware (such as dSPACE, Speedgoat, Opal-rt…). Simcenter Amesim then proposes various simplification techniques, from simplified lumped parameter model to Reduced Order Model (Neural Network models) generation

Virtual testing with MBD has multiple benefits:

• Early issue detection: simulation allows for early identification of design flaws and potential issues
• Comprehensive testing: virtual testing facilitates extensive evaluation of the BMS
• Iterative design improvements: using MBD allows rapid iteration and optimization
• Cost and time efficiency: virtual testing with MBD reduces development costs and time
• Risk mitigation: simulating hazardous scenarios virtually ensures safety without exposing hardware and personnel to risks

Simcenter Engineering services offers a complete service for implementing a comprehensive BMS software solution using industry best practices and MBD. Our consultants help you implement advanced BMS algorithms, integrate and implement AUTOSAR and deploy a methodology and framework to automate the verification testing of the BMS software.

Our experts can also enhance your processes by incorporating an application lifecycle management (ALM) solution, such as Polarion, to ensure compliance with International Organization for Standardization (ISO) 26262 and an automotive simulation program with integrated circuit emphasis (ASPICE).

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