| Summary: | 碩士 === 國立勤益科技大學 === 電機工程系 === 99 === This thesis studied an advanced battery management system (BMS) applicable to higher number of LiFePO4 cells in serial connections. This thesis focused on some critical issues in BMS of high numbers of LiFePO4 cells in series. They are cell voltage measurements, cell balance circuit and prediction of state of charge for the battery pack with many cells in series. The advanced BMS composed of various cell protection mechanisms including of overcharge, discharge, over temperature, and short circuit. A global type active balance circuit was invented and developed in the current study. The developed active balance circuit can produce 3A~6A of continuous balance current. The current BMS used industrial RS-485 as main communication protocol to communicate with human machine interface platform. RS-232 or USB protocol were also possible communication choice. The developed BMS also provided comprehensive faults LED indicators or alarming. The faults alarming could provide audible alarming to remind users and also taking precautions before protection mechanism taking effects. This BMS was installed on a five-seated electrical vehicle (EV) to test its performance. An energy management system based on the BMS developed from the current study was developed and thoroughly tested in the current study. The EV field test of the current BMS showed good performance and reliable management. The EV range was increased two times comparing to original lead acid battery. The good results in the EV field test demonstrated the feasibility of the developed advanced LiFePO4 BMS.
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