Development and validation of an integrated analog control system for a 30W PEM fuel cell powered by a 100W H2 generator

Abstract

This study addresses the need for intelligent management in integrated hydrogen energy systems by designing and validating a cost-effective analog control system for a proton exchange membrane (PEM) fuel cell stack powered by a PEM electrolyzer. The work first characterizes a commercial GL-200 electrolyzer, establishing a baseline hydrogen production rate of 210 ml/min at 185 kPa with an efficiency of 33.7–42.7%. The evaluation of its standard timer-based controller reveals critical limitations: a lack of real-time monitoring and a fixed exhaust cycle that induces voltage fluctuations exceeding 7 V under dynamic load. To overcome these issues, a novel analog controller was developed. The core optimization goal of this controller is to ensure stable and safe operational control of the integrated PEM fuel cell stack under dynamic conditions, with a primary focus on preventing voltage instability through adaptive purge cycle management. This system employs dedicated sensors to continuously monitor stack voltage, temperature, and pressure. Its key innovation is a pressure-triggered exhaust valve activation (at 200 kPa), which replaces the inflexible fixed-timer logic to achieve this goal. This results in significantly more stable and safer operation, maintaining a consistent stack output voltage of 10.5 V. A major advantage is the dramatic reduction in unit cost; the prototype controller is fabricated for under MYR 200, representing an approximately 18-fold reduction compared to the commercial benchmark. While the current prototype requires an external low-voltage power source, this work demonstrates a pivotal step towards viable, intelligent control for small-scale, renewable hydrogen-based power systems.