Design Of Digital Controller For Battery Management

With the continuous introduction of new energy policies,the rapid development of the global electric vehicle industry has led to the further expansion of the market size of lithium batteries.However,the chemical characteristics of lithium batteries are extremely lively,and it is prone to safety problems due to overvoltage and overtemperature during use.Therefore,a battery management chip is required to detect and protect the battery’s operating parameters during the operation of the lithium battery.As the core of the battery management chip,the digital controller is responsible for the communication between the battery management chip and the MCU to monitor,protect,and control the battery.Therefore,it is necessary to design the digital controller in the battery management chip.Based on the in-depth study of the working principles of battery management chips and digital controllers,three modules of monitoring,protection and control of digital controllers are designed.Among them,the monitoring module collects the battery voltage,temperature and current,adopts the time division multiplexing method to collect the voltage and temperature,design the balance enable register and the balance dedicated time to realize the balanced processing of the battery,the current sampling adopts the Coulomb integration method;For the protection module,in order to ensure the effectiveness of fault detection,a one-vote fault filtering algorithm is adopted to implement multiple hardware fault protection suc h as overvoltage and overcurrent,and the fault detection threshold and detection parameters can be configured;I2C communication,register and scheduling module are designed to realize the control function of the digital controller.I2 C communication is responsible for communicating with the MCU,writing data into the register,and controlling the chip with the time management of the scheduling module.Verilog hardware description language is used to describe each module of the digital controller.Using the analog circuit behavior level description and the I2 C host device verification model,a verification environment for a small battery management system is constructed to perform functional verification.The verification results show that the digital controller supports the standard 100 k Hz I2 C communication,which can realize the data interaction between the MCU and th e chip;it supports balanced processing,and can sample voltage and temperature in both normal and balanced working modes,and current sampling supports single sampling and continuous sampling;when various faults are triggered,the corresponding charge and discharge switches can be closed,and the fault is displayed in the status register,and various fault detection thresholds and detection parameter configurations can take effect.