Trace Moisture Measurement in Hydrogen Cooled Generators Application Note Hydrogen-cooled electricity generators are widely used in power plants because hydrogen offers exceptional thermal conductivity and low density, enabling efficient cooling of large generators. However, trace moisture measurement within these systems is critical for safety and performance. This article explains why dew point monitoring matters, highlights common moisture-related issues, and references key standards. Dewpoint measurement is essential for ensuring air quality and protecting downstream equipment. Why Hydrogen? Hydrogen is the preferred cooling medium for large stationary electric generators due to its unique properties: High Thermal Conductivity Hydrogen transfers heat more efficiently than dry air, ensuring optimal cooling. Low Density Minimises windage losses, improving generator efficiency. Non-Corrosive and Non-Toxic When properly managed, hydrogen is safe and does not damage generator components. Typical Hydrogen Cooled Generator System

Moisture Problems in Hydrogen Cooled Generators Moisture ingress can lead to severe operational and safety issues: • Reduced insulation resistance Condensed water on windings lowers insulation, increasing electrical fault risk. Moisture accelerates metal degradation, causing premature component failure. • Hydrogen purity reduction Water vapour dilutes hydrogen, reducing cooling efficiency and increasing explosion risk. • Safety hazards Excess moisture can form explosive hydrogen-oxygen mixtures Continuous dewpoint monitoring is essential for maintaining generator safety and performance. • Online...