Fuel cells and hydrogen for balancing renewable energy fluctuations: a control-oriented approach

This thesis focuses on developing a novel control algorithm, which is applied to balance power fluctuations of renewable energy sources using hydrogen as an energy vector. Power fluctuations are caused by intermittency of wind speed and solar irradiance, which is hard to forecast without a marginal error. Therefore, the uncertainty of prediction models of generation-side and demand-side is considered in the control algorithm. A Lab-scale microgrid is built including a generating-side emulator, a demand-side emulator, an electrolyser, a fuel cell, and a battery bank. A novel role of the battery is proposed in this thesis, whereby the battery power contributions are used for bringing the system in balanced conditions. The new role of the battery enables the energy balancing controller to perform the energy balance in a closed-loop control scheme and in real-time.

The proposed control algorithm is successfully applied to balance power fluctuations of the microgrid. The controller could balance power fluctuations if the system is provided with enough surplus energy that enables performing the balance over the designed operating time. Therefore, a successful energy balance should be incorporated with a good sizing of the renewables considering a planned load and meteorological data of a location.