Abstract:Currently, the launch vehicle provides one battery pack to each of them to supply power for the control system, measurement system, electromagnetic valve and explosive device load.Battery pack failure will lead to abnormal operation of the electrical system on the launch vehicle, and even lead to disastrous consequences such as mission failure in severe cases. Lithium battery pack is replacing traditional zinc-silver battery pack in launch vehicle fields, which has the advantages of high-energy storage density and long performance life. Aiming at the problem of no redundancy of battery power supply in launch vehicle field, the fault diagnosis of lithium battery is studied.According to the estimated result of SOC of lithium battery is used as the basis of battery fault diagnosis. The EKF algorithm is used to improve the estimation accuracy of SOC of lithium-ion battery; According to the fault diagnosis results, the intelligent switching of the failed single battery is completed through the topology reconfiguration of the battery pack, and the power supply redundant management system of launch vehicle is established.The simulation test meets the requirements of engineering application, and improves the reliability, safety and fault tolerance of the battery, which is of great significance for improving the reliability and safety of the launch vehicle.