#E/Earchitectures

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Understanding Battery Management System (BMS)

November 13, 2024

by dorleco

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eMOBILITY CONTROLS

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Introduction

The technology underlying electric cars (EVs) is developing quickly and increasing in popularity. The Battery Management System (BMS) is vital to any energy storage, renewable energy, or electric vehicle system. By keeping an eye on and controlling many facets of the battery’s condition and operation, a BMS guarantees the battery pack’s best performance, longevity, and safety. We will explore the fundamental ideas of BMS in this blog, including its operation, its main components, and the range of tasks it carries out.

What is a Battery Management System?

An electrical device called a Battery Management System (BMS) monitors and controls a rechargeable battery to ensure it runs within safe bounds. It is crucial for high-power applications, such as EVs, HEVs, renewable energy systems, and others, where battery life, safety, and efficiency are top concerns. In essence, the BMS serves as the battery pack’s brain, constantly monitoring its condition, preventing it from going beyond its safe bounds, and keeping it in top condition.

Why is BMS Crucial for EVs?

The battery functions as the primary power source in EVs. Because of its great importance, each cell in the pack needs to function at its best. A battery that is not properly maintained may overheat, lose its balance, degrade more quickly, or even provide safety risks such as thermal runaway. Consequently, the BMS of an EV is required to:

Increased Safety: Prevents issues like short circuits, overcharging, and over-discharging that could result in overheating or fires.

Extended Battery Life: Reduces battery deterioration by optimizing usage conditions.

Optimize Range: Assures that the battery operates at its maximum capacity, allowing the car to reach its ideal driving range.

Monitor Health: Keeps track of the battery’s condition and notifies users when maintenance or replacements are required.

How Does the Battery Management System Operate?

Fundamentally, a BMS gathers information from the battery pack, evaluates it, and then complies with the rules. Let’s overview in more detail:

Data Collection: Cell voltage, current, temperature, and occasionally other parameters like state of charge (SOC) and state of health (SOH) are all continuously monitored by the BMS.

Data Processing and Analysis: To ascertain the battery’s present state, the data is analyzed after it has been gathered. For example, the BMS can determine whether the battery is getting close to dangerous operating conditions by examining voltage and temperature information.

Making Decisions: To maintain a consistent condition, the BMS makes decisions based on its analysis about whether to modify current flows, activate cooling devices, or balance the battery pack’s cells.

Action: The BMS takes action, such as lowering power flow, activating heating/cooling systems, or notifying the user, if conditions deviate from safe bounds.

Essential Components of a Battery Management System

Generally speaking, a Battery Management System consists of several crucial parts, each with a distinct purpose. Let’s examine the primary components of a typical BMS in more detail:

1. Circuit for Cell Monitoring and Balancing

Cell Voltage Monitoring: Prevents overcharging or over-discharging by measuring the voltage of individual cells. Maintaining voltages within safe bounds is essential to extending battery life and avoiding thermal problems since batteries are sensitive to changes in voltage.

Cell Balancing Circuit: The cell balancing circuit makes sure that every cell in a battery pack has the same amount of charge. Because weaker cells deteriorate more quickly than others, imbalances can result in decreased battery life and performance. Balancing circuits distribute the charge among the cells to maintain equal charge levels in the battery pack.

2. Temperature Sensors:

Temperature monitoring is crucial since extremes in temperature can impair battery performance or potentially pose safety hazards. Thermistors or other temperature sensors are commonly used by a BMS to monitor battery pack temperatures and make sure cells are within ideal limits.

3. Current Sensors:

These sensors gauge how much current flows into and out of the battery pack. In addition to preventing overcurrent scenarios that could harm the battery or associated devices, this data is essential for determining SOC and SOH.

4. Microcontroller Unit (MCU)

The BMS’s central processing unit, the Microcontroller Unit (MCU), is in charge of executing algorithms, storing information, and making choices depending on the data that is monitored. It notifies the user, carries out directives such as cell balance, and interacts with other systems or vehicle controls.

5. Communication Interface:

The Battery Management System can communicate with other systems, including the vehicle control unit (VCU) in electric vehicles, by using a communication interface. CAN bus, I2C, and SPI are examples of common communication protocols that enable data exchange for smooth system integration.

6. Safety and Protection Circuitry:

Protection circuitry, which includes features like under-voltage, short-circuit, and overcurrent protection, makes sure the battery runs safely. As a final resort, these circuits guard against disastrous malfunctions.

Essential Features of a Battery Control System

A BMS performs several vital tasks to preserve the safety and health of batteries. Here is a detailed examination of each of these roles:

1. Estimation of State of Charge (SOC)

SOC estimate displays the battery’s current charge level as a percentage of its overall capacity. Understanding the SOC is crucial for both energy management and EV range prediction. Temperature and aging can make SOC calculation difficult, which is why BMS algorithms frequently use techniques like open-circuit voltage measurement or Coulomb counting to provide precise estimates.

2. State of Health (SOH) Monitoring:

SOH evaluates the general health and remaining lifespan of a battery. It considers things like capacity fading, degradation patterns, and cell resistance. SOH monitoring aids in long-term performance and cost savings by assisting users in determining when maintenance or replacements are required.

3. Cell balancing

As previously stated, cell balancing makes sure that every cell in a battery pack keeps the same amount of charge. Longer battery life and improved efficiency are made possible by this procedure, which stops weaker cells from affecting the performance of the entire pack.

4. Thermal Management:

Because batteries are temperature-sensitive, their lifespan and performance can be impacted by both high and low temperatures. By monitoring cell and pack temperatures and turning on heating or cooling equipment as necessary, a BMS manages thermal management. To maintain peak performance under a variety of circumstances, advanced BMS systems in EVs frequently incorporate temperature management.

5. Protection against Overcharge and Over-Discharge

If a battery cell is overcharged or over-discharged, it may cause irreparable harm, safety hazards, or decreased performance. Cell voltages are continuously monitored by the BMS, which will lower charging rates or cease charging completely if voltages rise above acceptable bounds.

6. Current Regulation:

To keep the battery’s current within acceptable bounds, the Battery Management System controls how much current enters and exits the battery. To avoid overcurrent situations, which can harm battery cells and other system components, this safeguard is crucial.

7. Diagnosis and Communication

A lot of Battery Management Systems have diagnostic features that allow them to log information like operational temperatures, charge cycles, and trends over time. Furthermore, the BMS can convey data and warnings to other systems via communication interfaces, facilitating remote diagnostics and monitoring.

Challenges in BMS Design and Development

Several obstacles must be balanced to create a dependable and effective BMS:

Variability in Battery Chemistry: Different chemistries have different tolerances for voltage, current, and temperature (e.g., lithium-ion, lithium-iron-phosphate). A BMS needs to be customized for the particular battery chemistry.

Environmental Considerations: Particularly in automotive applications, BMS systems must function in a range of temperature, humidity, and vibration situations.

Financial Restrictions: The price of integrating premium sensors, circuits, and processors into a BMS must be weighed against the battery pack’s total cost.

Accuracy in SOC/SOH prediction: Due to variables including temperature, cell aging, and usage patterns, it can be challenging to obtain accurate SOC and SOH readings, which are crucial for user confidence and range prediction in EVs.

Future Trends in BMS Technology

With advancements aimed at boosting efficiency, safety, and accuracy, BMS technology has a promising future. Among the major themes are:

Artificial Intelligence and Machine Learning: By learning from usage patterns, AI-powered BMS algorithms can enhance SOC and SOH estimations as well as predictive maintenance.

Solid-State Battery Compatibility: BMS technology will need to advance to accommodate various operating conditions as solid-state batteries proliferate.

Improved Connectivity and IoT: Real-time data sharing, remote diagnostics, and software updates are made possible by cloud connectivity and IoT integration, which can increase battery life and enhance user experience.

Conclusion

In applications like electric automobiles, battery management systems are essential for guaranteeing the performance, lifespan, and safety of contemporary battery packs. BMS technology will keep developing, providing more safety features, efficiency, and integration as battery technology advances and the need for energy storage solutions grows. BMS technology will become increasingly important in enabling a sustainable future as it advances in sophistication. The BMS is unquestionably the unsung hero behind the scenes, whether it is facilitating EVs’ increased range on a single charge or handling the intricate requirements of renewable energy storage.

Discover how electric vehicle performance will develop in the future with Dorleco’s top-tier automotive solutions! Our blog on Battery Management Systems (BMS) delves into the core of EV innovation, including information on battery longevity, safety, and efficiency — all of which are essential in the rapidly changing EV market of today. At Dorleco, we provide CAN Keypads, CAN Displays, and high-performance Vehicle Control Units (VCUs) for dependable and easy integration with your EV systems. We provide full solutions that maximize performance, minimize downtime, and improve the EV experience when combined with our extensive EV Software Services. Dorleco provides the technologies and know-how to assist you speed up your transition to the future of electric mobility, whether your goal is increasing battery efficiency or EV safety.

Visit us at Dorleco and learn how our cutting-edge solutions can power your next EV project.

[timestechnow]

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[dorleco]

Domain Controllers in Automotive Applications

November 5, 2024

by dorleco

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eMOBILITY CONTROLS

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Introduction

In automotive applications, Domain Controllers are a specialized computer that manages a set of vehicle functions within a specific area, or domain. Functional domains that typically need a domain controller require substantial computing power and are connected to numerous input/output (I/O) devices. Examples include active safety, user experience, and body and chassis functions.

Radars, cameras, and other sensors around the car provide inputs to an active safety domain controller, which then uses that data to build a model of the surroundings. Based on what the model indicates, software programs in the domain controller subsequently decide “policy and planning” what the vehicle should do. For instance, based on pre-set regulations, the software may use sensor-generated images to identify a pedestrian who will cross the road and trigger the car to either apply the brakes or warn the driver.

Types of Domain Controllers in Vehicles

According to their functional domain, domain controllers in the automotive sector usually fall into one of several major categories:

Powertrain Domain Controller: In charge of controlling the car’s engine, gearbox, and additional propulsion and power systems. These controllers are essential for maximizing performance, emissions, and fuel economy. Powertrain domain controllers regulate the motor, battery, and energy flow in electric cars.

Chassis and Body Domain Controller: These controllers regulate the vehicle’s body features like door locks, climate control, and lighting as well as its physical dynamics like steering, braking, and suspension. The vehicle’s comfort and safety are enhanced by chassis and body domain controllers.

Active Safety Domain Controller: Made to interpret information from radar, cameras, and sensors to make safety judgments in real-time. This domain controller is crucial for features like adaptive cruise control, automated emergency braking, and lane-keeping because it builds a model of the environment around the car.

Information entertainment and user experience Domain controllers are in charge of the infotainment system, instrument cluster, and other controls that interact with passengers, such as the navigation and climate systems. These controllers facilitate functions that improve the user’s engagement with the car, resulting in a smooth and joyful experience.

Why are Domain Controllers Essential?

Several factors are driving the growing use of domain controller in automobiles:

Complexity Reduction: As cars get more features, there are more electronic control units (ECUs), which makes the wiring system more complex. By combining many ECUs into a single, central controller, domain controllers simplify the wiring harness of the car and increase durability.

Increased Processing Capacity: As automobile technology has developed, cars now need a significant amount of processing power. The power required to manage complicated activities, such as processing radar data for active safety features or operating high-definition graphics for infotainment systems, is provided by domain controllers, which are tuned for certain functions.

Reduced Manufacturing Costs: Automakers can reduce costs related to components, wiring, and software development by reducing the number of ECUs by combining various functions into a single controller. Because fewer ECUs need to be integrated and deployed, domain controllers also expedite the production process.

Software Update Facilitation: Continuous enhancement of vehicle performance and features is made possible by over-the-air (OTA) software upgrades, which are made possible by a centralized controller configuration. As manufacturers remotely send out new features and safety improvements, OTA updates are becoming more and more valuable.

Domain Controllers and the Evolution of E/E Architecture

Because they enable further centralization and standardization of vehicle functions, domain controllers are fundamental to the development of automotive electrical/electronic (E/E) architecture. Conventional E/E designs are made up of dispersed ECUs that are each in charge of a certain task and are located throughout the car. But as car technology has developed, this model has grown unwieldy, necessitating a more efficient strategy.

Functions can be organized into discrete domains with domain controller, each of which is controlled by a strong controller. This is a big step toward a centralized computing model, in which almost all vehicle operations are managed by one or more powerful computers. It is anticipated that manufacturers will keep combining domain controller into a single computing platform in the future, which would streamline the design of the car, cut down on wire, and improve processing power.

Smart Vehicle ArchitectureTM (SVA), which aims to create a centralized E/E architecture based on domain controllers and central computer units, is a well-known illustration of this approach. Increased connection, enhanced energy efficiency, and scalable software-driven features — all crucial for electric and driverless cars — are made possible by this strategy.

Key Domains Controlled by Domain Controllers

1. Active Safety

Perhaps the most important component in modern automobiles, particularly those advancing toward greater degrees of autonomy, is the active safety domain controller. A variety of sensors located throughout the car, including as cameras, radars, and LiDAR, provide data to active safety controllers. The controller makes decisions about safety-related activities by using this data to build a model of the vehicle’s environment.

For example, the system may automatically apply the brakes or notify the driver if it detects a pedestrian in the route of the car. Features like adaptive cruise control, blind-spot identification, and lane departure warning depend on this domain controller.

2. User Experience

Domain controller oversee in-cabin amenities like the infotainment system, climate control, and digital instrument clusters in the context of user experience. To provide a seamless user experience, this domain controller works with a variety of input/output devices, including touchscreens, audio systems, and reconfigurable displays.

User experience domain controllers make it possible to seamlessly integrate cell phones, cloud services, and sophisticated voice and gesture controls with the trend toward linked and personalized automobiles. They enable automakers to provide a customized driving experience that can be adjusted to suit each customer’s tastes.

Chassis and body suspension, braking, steering, lighting, and door control are among the structural and motion-related operations managed by the body and chassis domain controller. Because it allows for precise control over the vehicle’s physical characteristics, this domain improves comfort and safety. For example, it can activate adaptive headlight systems that change according to steering angle and speed, or it can modify the suspension according to road conditions to improve ride quality.

The advantages of domain controllers

The following advantages of domain controller make them very appealing to automakers:

Better Performance: Automakers can enhance processing speed and performance by optimizing hardware and software for certain activities through the use of domain-specific controllers.

Cost-effectiveness: By lowering the number of separate ECUs, domain controllers contribute to lower production, wiring, and system integration expenses. Scalability: Due to its capacity to adapt to changing software requirements, domain controllers facilitate the addition of new features and upgrades.

Enhanced Security: As cars become more interconnected, safeguarding data and managing cyber security threats becomes more crucial. This is made possible by fewer, centralized computing nodes.

Challenges and Considerations

Although domain controllers have many benefits, there are drawbacks as well:

High Development Costs: A substantial investment is needed to create domain controllers with adequate processing power and resilience.

Complex Integration: In a vehicle with several systems, it can be difficult for domain controllers to connect across multiple domains with ease.

Heat Management: Domain controllers produce a lot of heat when they perform more computing duties, which calls for sophisticated thermal management solutions.

The Future of Domain Controllers

Domain controllers will play an increasingly important role as the automotive industry moves toward electrified and fully driverless vehicles.

Domain controller will likely be combined into centralized, high-performance computing systems that can handle several domains at once in the upcoming years.

By streamlining the architecture and enabling quicker development cycles, this approach will open the door for “vehicle computers” that manage almost all vehicle tasks. Advanced driving assistance systems (ADAS), AI-driven features, and connected automobile services will all be made possible by such centralized infrastructures.

Domain controllers are a crucial stage in the progression of the automotive industry toward complex E/E architectures. Domain controller contribute to the development of future automobiles by centralizing operations, increasing processing capacity, and facilitating a scalable platform.

Connect with us to learn more about domain controllers and explore our EV software services, including VCUs, CAN Keypads, CAN Displays, and more. For details, contact info@dorleco.com.