A method to extract lumped thermal networks of capacitors for reliability oriented design

In this work we propose a procedure based on finite element simulations to compute a lumped-parameter thermal model of capacitors. The extracted Foster or Cauer network coupled to the electrical model can be useful to evaluate the temperature of capacitors in circuit simulators as SPICE or Simulink. In this way, it is possible to evaluate the expected maximum operative temperature of the capacitor embedded in a circuit before its real application, avoiding unexpected failures since the prototyping stage. Here, we describe the workflow of the method and, finally, the proposed approach will be used for designing snubber capacitors for medium power (60 kW) high frequency AC/AC converter.