Lead-acid Battery Management System Hardware And Software Research

This paper proposes a battery management system, which includes battery state detection, equalizing charge/discharge management, temperature management and charge/discharge management. Battery state detection comprises estimation of SoC (State of Charge) and detection of SoH (State of Health). SoC describes the short-term behavior of the battery, and SoH depicts the long-term behavior of the battery. A novel method used for estimation of SoC is proposed, which is based on AH principle, Peukert equation, temperature correction and SoH. What's more, a new method used for detection of SoH is proposed, which can carry out on-line.A new switch module is proposed in this paper, which can save 40% of the whole swithes. The control of the switch module is realized by PLD, which contains hardware fault-tolerance. Thus the complexity of the system is reduced and the reliability of the system is enhanced. The swith module can also be used in voltage circulation detection system. The switch unit is replaced by AQ212, a PhotoMOS solid-state relay which is produced by Panasonic. As a result, the drive circuit can be simplified.And a novel battery charge circuit used for main charger of the battery management system is proposed in this paper too. The proposed charge circuit can significantly reduce the circumfluent loss appearing in the conventional phase-shifted full bridge. And it can achieve ZVS over almost the full load-range, which results in high efficiency. Even more, the requirements to the filter both at the input and the output can be also significantly reduced. Experimental results verify the analysis.Finally, designs of the other components of the battery management system are proposed, and pictures of the prototype are depicted too.