Integrated Electro-thermal Design Methodology in Distributed Power Systems (DPS)

Abstract

Although suitable CAD tools for thermal and electrical analyses in power electronic systems are available, traditional stand-alone simulation method seldom takes into consideration of the inter-dependency of semiconductor device power loss and junction temperature in an iterative process. However these dependencies are important, especially for applications where both cooling and power losses are driven by complex mechanisms.

For a power supply system, a dynamic design process is necessary to address both electrical and thermal issues. It is because the steady state temperatures of the system are obtained from loss-and-temperature iteration. Once a system solid body model is built, iterations between power loss and junction temperature calculations are performed to obtain the steady state temperature distribution. Since reliability and failure rate of components are directly related to temperatures, an accurate model is critical to provide proper thermal management, which achieves maximum power density. All cooling-related data such as placement of components, airflow rate, heat sink size, and device types are subjected to design changes in order to meet ultimately the temperature requirements.

The goal of this thesis is to demonstrate the benefits of integrated analysis and design tools applied in distributed power supply systems designs. First, it will significantly speed up the design process and eliminate the errors resulting from repeated manual data entry and information exchange. Second, the integrated electrical-thermal design tools encompass electrical, thermal, layout, and packaging design to obtain the optimal system design.