Electro-Thermal Average Modeling of a Boost Converter Considering Device Self-heating

Due to the ongoing pursuit of high power density power supplies, thermal management becomes one of the most critical aspects to consider during the design phase for their stable and efficient operation. There are some reported electro-thermal models (ETMs) of power semiconductors and passive components, which help to estimate their electrical performance and temperature simultaneously. However, with the increase of the switching frequency for higher power density design, the simulation time increases accordingly. This can be effectively solved by adopting an averaged model of the converter. As the conventional average model is neither frequency nor temperature dependent with which are the two key parameters in ETM, modification is needed. Therefore, a modified electro-thermal average model (ETAM) of a boost converter considering self-heating phenomenon of all devices is proposed in this paper. This is achieved by a) adding additional behavior models to calculate the device losses; b) replacing the fixed resistance of each component with a temperature dependent one; c) using variable inductor and capacitor instead of a fixed value counterpart to obtain an accurate electrical model and precise losses estimation, and d) forming electrical and temperature feedback loops for each component. The advantages of the proposed research work are fast simulation speed, fairly accurate temperature prediction, and ease of implementation. Both the simulation and experimental results are given and compared to verify the proposed solution