Analytical‐Numerical Hybrid Solution for Transient Thermal Analysis of the Outer Gate IGCT Considering Electrical‐Thermal Coupling

ABSTRACT The integrated‐gate commutated thyristor (IGCT), known for its low conduction losses and high reliability, is increasingly favoured in high‐voltage and high‐power applications. The junction temperature is a critical determinant of reliability, making the rapid and precise analysis of the transient temperature field indispensable. An analytical‐numerical hybrid solution for the transient thermal analysis of the outer gate IGCT considering electrical‐thermal coupling is proposed. Validation against FEA confirms the accuracy of the proposed analytical solution, while its computation time is reduced by 94.9%, which underscores its superiority in computational efficiency. Based on this, the proposed analytical‐numerical hybrid solution is integrated into the VSC‐HVDC simulation model, utilising the calculated maximum junction temperature feedback to optimise the switching frequency of VSC. Simulation results demonstrate that controlling the switching frequency based on the maximum temperature calculated can reduce the device's maximum junction temperature during VSC overload conditions, thereby enhancing the overload capacity of the converter. The analytical‐numerical hybrid solution proposed in this article can be used for system simulation and has the potential to be applied to active thermal management of converters.