<p>Hydrogen fuel cells are increasingly utilized in high-efficiency, environmentally friendly power systems, yet their low voltage and high current output require advanced power conversion techniques. Multi-phase interleaved boost converters (IBCs) are widely adopted in these applications for their ability to reduce input and output current ripple and distribute thermal stress among components. While the interleaved structure ensures a low RMS current for the input capacitor—thus guaranteeing its longevity—the output capacitor is subjected to significantly higher RMS current, which can lead to overheating, accelerated aging, and reduced system reliability. Minimizing the output capacitor’s RMS current is therefore critical for improving converter efficiency and extending component lifespan. This paper analyzes phase control strategies in N-phase interleaved boost converters for hydrogen fuel cell systems, focusing on reducing output capacitor RMS current. Theoretical analysis, simulation, and experimental results demonstrate that optimized phase control can significantly lower RMS current stress on the output capacitor, enabling the use of smaller, more reliable capacitors and enhancing overall system durability. The findings provide practical guidelines for designing robust and long-lasting power conditioning systems for hydrogen fuel cell applications.</p>