Control and Power Management of a Stationary Fuel Cell Hybrid System

This thesis proposes robust control and power management strategy for a 6kW stationary fuel cell hybrid power system to improve system stability and efficiency and to reduce fuel consumptions.
The thesis deals with a 6kW stationary hybrid fuel cell system that was developed by a Taiwanese company M-Field. The 6kW system consist of two PEMFC modules, batteries and electrical components to form a parallel hybrid power system. The system was designed for telecom base stations to provide uninterruptible power during emergency power failures. First, the batteries were charged before the main power was shut down. In case of grid power failures, the batteries will start-up the balance-of-plant (BOP) of the PEMFC modules. Then power is continuously provided by the parallel hybrid power system. At low current load, the PEMFC modules provide steady power for the base station. At high current load, both the PEMFC modules and batteries provide electricity to the base station. we apply robust control and power management techniques to improve the stability and efficinency of the stationary system. The study was carried out by four steps: First, we apply robust control to the PEMFC modules to improve the system’s performance. Second, we replace the original lead-acid batteries with lithium-iron batteries, and compare their performance and efficiency. Third, we analyse the efficiency of the electrical components to estimate total energy loss. Lastly, we integrate the stationary fuel cell hybrid power system and verify system performance by experiments. Based on the results, the proposed robust control and power management are deemed effective in improving system stability and performance.