Computational light junction temperature estimator for active thermal control

The junction temperature of power semiconductors in power converters must not exceed its maximum limits and it is of major importance for several failure mechanisms. But still, the junction temperature is hard to access. Direct measurement is not practical for industrial applications, indirect measurements require substantial effort and available junction temperature models have high calculation effort. This work develops a simple junction temperature estimator, which is applied for a maximum junction temperature limitation and the capability to be applied for further algorithm relying on the junction temperature, referring to active thermal control. It is experimentally shown, that a second order estimator is sufficient to achieve high bandwidth estimation.