How does electric vehicle BMS help batteries operate efficiently and stably?

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How does electric vehicle BMS help batteries operate efficiently and stably? [Copy link]

The battery is a key element in determining the performance, safety and efficiency of electric vehicles and is the heart of these vehicles. The battery management system (BMS) is a complex technology that performs the complex operations of managing the battery.

What is a Battery Management System (BMS)?

A battery management system is an electronic system that controls and protects rechargeable batteries to ensure their optimal performance, lifespan, and safety. BMS tracks the condition of the battery, generates secondary data, and produces reports of key information. State of charge (SOC), state of health (SOH), and remaining capacity are three important metrics that BMS tracks and calculates. In addition, it monitors key variables such as current, voltage, and temperature. In addition, BMS actively protects the battery from risks such as deep discharge, overcharging, overheating, and overcurrent.

In addition to providing protection, the BMS also regulates the battery's environment by controlling the heating or cooling system to keep the battery operating within an ideal temperature range. Cell balancing is another important function of the BMS, which ensures that each cell in the battery pack is charged and discharged evenly, thereby improving the overall performance and durability of the battery. The reliability and safety of modern rechargeable batteries are maintained by the system's extensive monitoring, reporting and protection functions.

The BMS acts as the "brains" of the battery pack in many ways. It makes decisions based on the information it collects, and those choices affect the performance and life of the battery. Without a BMS, the battery could be overcharged or over-discharged, both of which have the potential to shorten battery life and cause battery failure.

The role of BMS in electric vehicles

A BMS is typically an embedded system and specially designed electronic regulator that monitors and controls various battery parameters such as temperature, voltage, and current to keep the battery cells within a safe operating range. Figure 1 depicts the overall structure of a BMS used in an electric vehicle. The input, data processing, and output signals used in a BMS can be used to depict the data flow according to the architectural design.

Figure 1: Internal architecture of an electric vehicle BMS

The BMS plays many key roles in electric vehicles, including monitoring, protection, balancing, and thermal management. These functions are described in more detail below.

monitor

The battery's voltage, current, temperature, and SOC are all continuously monitored by the BMS. This information is critical in order to assess the battery's performance and condition. For example, SOC measures the remaining charge in the battery, which has a direct impact on the mileage of an electric vehicle.

The BMS also tracks the battery’s SOH, an indicator of the battery’s overall health. SOH can provide early warning of potential battery problems, enabling preventive maintenance or replacement of failed batteries.

Protect

The BMS protects against problems that could damage the battery and, in turn, the car. These protections include over-current (OC), over-voltage (OV), under-voltage (UV), over-temperature (OT), and under-temperature (UT) conditions. The BMS ensures the life and safety of the battery by prohibiting it from operating outside of its safe operating area (SOA).

Overcurrent protection (OCP) prevents large currents exceeding the battery's allowed current rating, which can cause overheating and battery damage. To prevent the battery from charging or discharging beyond a safe range, which can result in a shortened battery life or even battery failure, overvoltage protection (OVP) and undervoltage protection (UVP) are used. Overtemperature protection (OTP) and undertemperature protection keep the battery operating within a safe temperature range, preventing damage from extreme heat or cold.

balance

Another important job of the BMS is cell balancing. Since an EV battery pack is made up of many individual cells, it is critical to keep all the cells charged evenly. The BMS achieves this through active or passive balancing, which improves the overall efficiency and durability of the battery pack.

During active balancing, charge is transferred from high-charge cells to low-charge cells to keep all cells at the same charge level. On the other hand, using shunt resistors in passive balancing causes the excess charge of high-charge cells to be dissipated as heat instead of being transferred between cells. By continuously charging without dissipating the charge, the low-charge cells can catch up using this technique. Over several charging cycles, passive balancing gradually improves the uniformity of the state of charge between cells by preventing any one cell from overcharging. Both techniques attempt to increase the capacity and life of a battery pack, but active balancing is more effective because it redistributes the charge instead of dissipating it as heat.

Thermal Management

The BMS is critical to controlling the temperature inside the battery pack. It helps prevent overheating, a condition that can lead to shortened battery life or even thermal runaway, by monitoring the temperature and deploying cooling technology as needed.

A dangerous condition called thermal runaway occurs when a sudden increase in temperature causes further temperature increases, which can result in an uncontrollable and destructive reaction. A BMS can prevent thermal runaway and ensure safe operation of the battery by monitoring the temperature of the battery cells and taking action as needed.

The future of BMS for electric vehicles

As electric vehicle technology advances, battery management systems (BMS) are becoming increasingly complex. Future BMS are expected to include cutting-edge features such as predictive analytics for greater performance optimization, enhanced safety protocols, and better integration with other vehicle systems.

Predictive analytics uses historical data and machine learning algorithms to predict the future. This may involve predicting past performance to predict the future state of charge (SOC) or overall health of a battery in a battery management system (BMS). This will make it possible to manage the battery more proactively, extending its life and improving the efficiency of electric vehicles.

Improved safety standards could include more advanced techniques for predicting and avoiding potential battery problems. This could require more complex algorithms to spot anomalies that could point to potential problems, as well as more comprehensive monitoring of battery conditions.

The BMS can communicate more directly with other EV systems, such as the motor controller or onboard computer, to improve integration with other vehicle systems. This could make the car run more smoothly, improving its efficiency, performance and user experience.

in conclusion

In summary, the battery management system (BMS) is an essential component of electric vehicles, used to manage, protect and monitor the battery. Understanding the nature and purpose of BMS will help us better understand the complex interaction of technologies that power current and future electric vehicles.

As we continue to advance and push the limits of what is feasible for electric vehicles, BMS will inevitably evolve and change. By keeping up with these improvements, we can ensure we are leveraging the full potential of this technology to create safer, more efficient, and more sustainable electric vehicles.

Whether you are an electric vehicle manufacturer, a BMS system manufacturer, or a enthusiast of the technology, it is important to understand the function and importance of BMS. As electric vehicles become more widely used, BMS will continue to be a key component of this innovative technology field.