Design of a PIC Microprocessor-Based Energy Saving Charge Equalization System

• Main Authors: Jen Feng Li, 李任豐
• Other Authors: W. L. Chen
• Format: Others
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/00991872895226958212

碩士 === 長庚大學 === 電機工程學系 === 98 === Batteries with higher state of charge (SOC) in a series connected battery string suffered from higher charging power would reach full charge before the overall battery terminal voltage attains its nominal voltage. If constant charging current is ongoing, these batteries are charged into gassing and prone to dramatic reduction in life and potential damage. To equalize the state of charge for a series connected battery string, an energy saving charge equalization strategy is presented. Rather than traditional strategies redistribute the charge energy according to the dynamic battery voltage, the proposed strategy inserts a rest period between equalization cycles such that the battery open circuit voltage serving as a relative SOC indicator to the charge equalization control isdetectable. The rest period is also advantageous to convert the battery charge into chemical energy, so as to alleviate the undesired products like gas and heat.The proposed equalization strategy was realized by a peripheral interface controller (PIC)-based experimental setup in which a nondissipative buck-boost converter is used as charging current re-distributor and a push-pull converter is mandatory to fully charge the battery string. The experimental results confirm the performance of the proposed strategy.