Electric vehicles have always been concerned with clean and environmental protection. Coupled with the energy crisis and rising oil prices, electric vehicles are increasingly favored by users. The electric vehicle is generally powered by a lithium battery, and a plurality of single cells are connected in series to form a battery pack as a power source. However, since the characteristics of each series cell are not guaranteed to be completely uniform, the charging and discharging speeds will be different under the same current. If the balancing intervention is not performed, the battery life will be greatly shortened, so it is necessary to monitor the state and total voltage of each cell in real time. The total current, according to the state of the battery charge and discharge equalization, and the charge and discharge balance, the equilibrium state should also be detected in real time, so there is an electric vehicle battery energy management system (EMS). Practice has proved that EMS can effectively extend the battery life of electric vehicles and is an important management system in electric vehicles.
The EMS mainly includes an information collection module, a charge and discharge equalization module, an information centralized processing module, and a display module. Figure 1 is a structural diagram of the self-developed electric vehicle battery energy management system (EMS). The information acquisition module mainly completes the real-time collection of the battery pack and the voltage, temperature, current and other status of the single battery, and also monitors the battery in real time. Provides a basis for the opening and closing of the equalization module. The equalization module mainly compensates for the difference in battery characteristics, determines the state of the battery according to the information collected by the acquisition module, and performs charge and discharge equalization on a single battery to achieve consistent state characteristics. The information centralized processing module is responsible for processing, analyzing, and calculating the collected data (such as SOC, etc.), and monitoring the work of the equalization module, controlling it, and communicating with the display module, playing a role in the whole system. As the only human-computer interaction interface, the display module not only carries all the data and device status to the user in real time, but also allows the user to visually see the battery status and EMS work effect, and also provides the user with the EMS control communication. The interface allows the user to set parameters and change the working status of the EMS to achieve real-time supervision and control.
If there is no display module, people can't see the battery and EMS information. The alarm or prompt information of EMS can't be notified to the customer. Some alarm status can't be processed in time, which will cause battery damage, which will lead to the loss of control of the electric vehicle. Become a serious accident. Similarly, customers can't adjust and control EMS according to the situation, and they can't fully play the role of EMS. It can be seen that the human-computer interaction function of the display module is an indispensable component of the EMS. It is a good choice to see the touch screen from the functions required by the display module. However, if the touch screen on the market is purchased, not only the display content will be limited by the display function of the touch screen itself, but also the flexibility of the display design and the display quality are affected, and the price of the touch screen on the market is generally higher, which adds a large part to the product. Cost, which will undoubtedly greatly reduce the market competitiveness of products. Based on this situation, this paper proposes a design scheme of a relatively common LCD touch screen with STM32F103 microcontroller as the control core.
