Monitoring of the Cooling System via Thermal Parameters

The cooling system, including the thermal grease, heatsinks, plays an important role in the power converters for its reliable operation. While in the long-term operation situation, the cooling system will degrade with different kinds of failure mechanism of the components and finally result in the damage to the power converters. In this paper, the method was proposed to monitor the thermal network parameters of the cooling system using the cooling curves of junction temperature. By establishing the relationship between the RC parameters of Cauer network and time constants of cooling curves, the thermal parameters about cooling system can be obtained. Experimental tests are performed to verify the accuracy of proposed method. Results indicate the degradation state of the cooling system can be evaluated by monitoring the variation of thermal network parameters of the cooling system.