Improvement of an industrial rule-based EMS for a hybrid PEM fuel cell system considering degradation mechanisms Integration internship

Abstract

In the context of rising electricity demand, increasing reliance on renewable energy sources, and the need for resilient infrastructure, stationary energy systems are expected to become more decentralized and flexible. Proton exchange membrane fuel cells represent a promising technology for addressing these challenges, particularly when combined with energy storage devices. Their ability to deliver clean and controllable power makes them suitable candidates for backup applications in critical sectors. However, their widespread deployment remains limited by high operating costs and performance degradation over time.

This thesis investigates the techno-economic optimization of a hybrid energy system based on a proton exchange membrane fuel cell system and a hybrid ultracapacitor. The work is anchored in a real industrial use case, involving the design of a backup power solution for infrastructures requiring high reliability. The main objective was to develop a control strategy that accounts for both system efficiency and degradation mechanisms, in order to reduce the levelized cost of energy and extend operational lifetime.

A steady-state 0D model was developed to simulate the system, including the fuel cell stack, compressor, humidifier, and an optional turbine for energy recovery. Two configurations were analyzed: a base system and a turbocharged variant. The integration of the turbine led to efficiency gains of up to 7 % at full load, although the economic benefit remained modest under standard load conditions.

To estimate system lifetime under realistic conditions, an empirical degradation model was implemented and calibrated using manufacturer data. This model was then integrated into the energy management system, together with the fuel cell and balance of plant models, to account for the main performance and durability constraints. Several rule-based control strategies were developed to dynamically manage the power distribution between the fuel cell and the hybrid ultracapacitor. When applied to a representative case study, the most effective strategy achieved a 13 % reduction in the levelized cost of electricity compared to the baseline configuration.

The results confirm that incorporating degradation into the control logic significantly improves both durability and cost-efficiency. This work offers a practical and adaptable framework for the deployment of proton exchange membrane fuel cell systems in stationary applications.