Performance evaluation of power management systems in microbial fuel cell-based energy harvesting applications for driving small electronic devices

Power management system (PMS) is critical for driving electronic loads using energy harvested by microbial fuel cells (MFCs). Two promising MFC PMS designs, charge pump-capacitor-converter type and capacitor-transformer- converter type, are presented and compared in their performance in driving a wireless sensing system. It is found that the capacitor-transformer-converter type PMS can accommodate lower input voltages, but the charge pump-capacitor-converter type PMS has a slightly higher power efficiency. Furthermore, the charging speed of the capacitor-transformer-converter type PMS is not limited by the charge pump as in the charge pump-capacitor-converter type PMS, resulting in a shorter charging/discharging cycle. The findings suggest that for loads with large duty cycles comparable to the charging time, the charge pump-capacitor-converter type PMS is recommended for its higher power efficiency; on the other hand, for ultra-low MFC output and/or time-sensitive missions, the capacitor-transformer-converter type PMS is recommended for its wider input voltage range and shorter charging/discharging cycle. Highlights: Different power management systems (PMSs) for microbial fuel cells are evaluated. Charge pump-capacitor-converter type PMS has a higher power efficiency. Capacitor-transformer-converter type PMS has a shorter charging/discharging cycle.