Research on current-sharing control method of energy storage device

Energy storage device is widely used in vehicle and ship, as the only or the backup DC power supply. For multiple energy storage devices operating in parallel, it´s necessary to adopt current-sharing control to improve the safety and the reliability of these devices. There are many current-sharing algorithms, such as the maximum current current-sharing method, the average current current-sharing method, the master-slave current-sharing method, etc. The advantages of the maximum current current-sharing method are that it has simple current-sharing circuit, good current-sharing effect and reliable operation; and its disadvantage is that it can just realize dynamic current-sharing. This disadvantage generates low frequency oscillation in the output current of DC power supply, and causes the phenomenon of overvoltage. The current-sharing circuit with double current-sharing buses can provides more feedback information and can achieve steady current-sharing control which can eliminate the phenomenon of low frequency oscillation and overvoltage at all.