At first, BMS only had the functions of monitoring battery pack voltage, current, temperature, etc. The main purpose was to realize the monitoring of battery pack. With the development of technology, BMS not only can monitor the battery pack, but also can control and manage the battery pack according to the information of the battery pack. A good BMS can significantly improve the efficiency and service life of the battery pack, and greatly improve the practicability of the BMS. It has now become one of the core technologies of electric vehicles.
In the BMS market, at the initial stage of the new energy vehicle market, battery cell companies and vehicle companies began to reserve technology in the BMS field, and most of the early participants were professional third-party BMS companies. With the explosive growth of the new energy vehicle market, batteries and vehicles have gradually entered this field in order to master this core technology. In the short term, third-party BMS companies will remain mainstream in the market. In the long run, automakers and battery companies will gradually penetrate, the industry will have a wave of consolidation, and the market concentration will increase. In the future, the third-party BMS, the battery factory’s own BMS, and the vehicle factory’s own BMS enterprises will have a tripartite presence.
The future research focus of BMS will also focus on the following aspects:
(1) State estimation technology. Accurate estimation of SOC, SOH, SOP and other technologies will continue to be the focus of future research. Based on accurate battery modeling, combined with information management, big data, and adaptive learning algorithms, high-precision state estimation of the battery life cycle is achieved.
(2) Active balancing technology. It can improve the consistency of the battery pack, slow down the attenuation of the battery pack, and increase the service life of the battery pack. This is the direction of future research, especially with the development of the echelon utilization of power batteries, active balancing can greatly improve the efficiency of echelon batteries. In the future, the research focus of equalization technology will be on the equilibrium topology, equilibrium strategy and equilibrium stability and reliability, so as to realize the optimal control of equilibrium.
(3) Distributed battery management system. The distributed management system integrates the battery module and the battery acquisition unit to realize intelligent and standardized battery modules. The advantage of this structure is that the module assembly process can be simplified, the sampling harness is relatively easy to fix, the harness distance is uniform, and there is no problem of uneven voltage drop; it is easy to standardize and modularize the battery module, and is convenient for the use of batteries. This architecture solves the problem of complex wiring harnesses through the bus mode, and is relatively simple to install, efficient, and flexible, and is suitable for different battery pack sizes.
(4) Integrated design. With the development of integrated circuits, the functions and resources of the microcontroller MCU have been greatly enhanced, providing the possibility for the integration of the BMS main control and the vehicle controller. By simplifying the responsibilities of the BMS and making it more focused on the management of the battery itself, the integrated vehicle controller realizes a more reasonable control of the vehicle based on the vehicle information and battery information. The system reduces the intermediate links, improves the real-time, safety, and reliability of the vehicle system, reduces the main control components of the BMS, and greatly reduces the cost of the system.
(5) The full life cycle management of the battery. In order to save energy, protect the environment, and maximize the use value of batteries, the echelon utilization of power batteries after retiring has become a hot spot for the entire industry. The current research focus is on the management of the full life cycle of batteries through various means.
(6) Functional safety. ISO26262 provides a specific risk-based analysis method for automobiles to determine the automobile safety integrity level ASIL, and provides a safe life cycle of automobile products.
(7) Diagnostic technology of battery. It is a technology that has gradually been valued in recent years. It requires the battery management system to have a good understanding of the characteristics of the battery and be able to determine whether the battery has failed or is at risk of failure when the battery is working or idle. In addition, the advanced battery diagnosis technology also includes how to measure the consistency of the batteries in the battery pack, and functions such as battery pack self-activation and self-repair.
(8) Low-cost technology. With the large-scale development of electric vehicles, the cost of battery management systems has gradually become the focus of attention. How to realize the low-cost design of the battery management system on the basis of ensuring safety and reliability requires efforts in various aspects such as system architecture and chip design.