Design Of Electric Vehicle Chip Based On Battery Protection And State Analysis In The Circuit

With it's advantages of performance, Lithium iron phosphate battery has become the most suitable energy storage device of electric vehicle. In the use of electric vehicles, in order to make the lithium iron phosphate battery more safe and reliable, and to extend the battery life, it needs to carry on state analysis and protection of the battery.Based on the research of the characteristics of the lithium iron phosphate battery and the protection of the chip, a chip which is suitable for the protection and state analysis of lithium iron phosphate battery is developed. At the same time, this paper focuses on the design of equalization circuit, SOC estimation circuit and protection module. The chip can not only on the battery of non normal state to make judgment and protection by controlling external circuit of the battery, but also realizing the balance of power between the battery, so that the service life of the battery to further extend. In this paper, we have two innovations: First, the chip has functions including the battery protection, power balanced and SOC estimation; second, under the control of the state of charge chip not only in preventing the battery charge but the external circuit can still work normally by changing the external circuit control. This method for system to a plurality of batteries in seriesThe chip was designed using CSMC 0.5um CMOS technology. The circuits have been simulated by Cadence software. The simulation results show that the chip can realize the accurate judgment of the battery state. At the same time, it can realize the protection of the battery, and the function of SOC estimation and power balance is in accordance with the design requirements.