• • At 35 °C and 50% RH, the average friction coefficient is 0.1297, a 46.6% reduction from the maximum of 0.2427 at 25 °C and 55% RH. This translates to lower mechanical energy losses and reduced wear in hydroelectric generator brush systems, potentially extending maintenance intervals.
• • The minimum average contact resistance of 1.52 Ω occurs at 25 °C/50% RH and 40 °C/45% RH, a 49.3% decrease from the maximum of 2.27 Ω at 25 °C/40% RH. Lower contact resistance reduces Joule heating and improves electrical efficiency, critical for high-current applications.
• • Wear rate is minimized at 50% RH, with increased humidity reducing surface roughness and promoting water film formation that acts as a lubricant. This mitigates abrasive and adhesive wear, with adhesive wear lowest near 50% RH, enhancing brush longevity.
• • Contact temperature follows an 'N'-shaped trend with increasing temperature at constant humidity, and at 30 °C, friction coefficient, wear rate, and contact resistance all reach relatively low values. This non-monotonic behavior underscores the need for precise environmental control to avoid performance degradation.