As offshore wind turbines grow larger, converter power modules face tougher thermal reliability requirements, making thermal-rise validation essential. Reliable testing requires stable long-duration loading and repeatable conditions, not just high current output. The IT7900 four-quadrant regenerative grid simulator provides stable power boundaries, protection and data logging to study hotspots and thermal equilibrium. This scalable platform delivers credible engineering evidence and improves test efficiency and data consistency for wind power thermal validation.