Dynamic simulation and power control of a hybrid solar-wind-fuel cell residential microgrid

Abstract

Hydrogen-based hybrid renewable energy systems (HRES) are rapidly advancing since they use green technologies for power generators and for back-up-power generators to satisfy the increasing energy demand with minimal greenhouse gas emissions. Combining current renewable energy technologies with energy storage systems can promote energy security, decentralize the electrification process, and expand access to electricity in remote and/or localized areas. Unlike battery-based HRES, hydrogen-based HRESs are advantageous since they have faster energy response, and they do not require periodic charging and discharging.

The goal of this project was to explore and evaluate the ability of a hydrogen-based HRES consisting of a solar energy system, wind energy system, and a proton-exchange membrane fuel cell (PEMFC) stack to meet the local energy demand in Fukuoka, Japan under different weather conditions with and without the battery storage system. The feasibility of hydrogen storage was also studied for the PEMFC stack and battery back-up HRES. MATLAB and Simulink were used to model the performance of this HRES using the PEMFC stack as the back-up generator with and without the battery storage system. The system was evaluated using meteorological data from four different weather scenarios, each for a span of 72 hours, that occurred in Fukuoka, Japan: 1) Clear days, 2) High wind speed days, 3) Cloudy days, and 4) Raining days.

The results indicated that connecting the PEMFC stack to the HRES with the battery storage system could satisfy the load demand in all four weather scenarios with an added advantage of a consistent supply of output power from the PEMFC stack if the supply of hydrogen fuel to the stack was met. Additionally, the battery helped this configuration to reach a reference voltage of 12V, which is important for the HRES to function optimally. The PEMFC stack also positively impacted the SOC of the battery. These results imply that using a dual energy storage configuration consisting of a PEMFC stack and battery could potentially reduce the battery size due to reduced power requirements from the battery. Lastly, an HRES with just the PEMFC stack as back-up showed large fluctuations in the DC bus voltage that prevented the system from responding accurately to the various energy generation sources. In summary, real-time data validation helped to confirm if the use of PEMFC stack is a viable and reasonable back-up storage option for HRES.