A Highly-Integrated SiC Power Module for Fast Switching DC-DC Converters
Alexander Stippich, Tobias Kamp, Alexander Sewergin, Lukas Fraeger, Arne Hendrik Wienhausen, David Bündgen, and Rik W. De Doncker,
2019 IEEE Energy Conversion Congress and Exposition (ECCE)
This paper addresses design elements of highly-integrated silicon carbide power modules allowing fast switching transients and, consequently, elevated PWM frequencies for dc-dc converters with high power densities. However, a minimal stray inductance is crucial for applications at high PWM frequencies. It is realized in this work using two key features: an electrical layout is proposed that creates an optimized commutation loop with minimized self-inductance on the basis of direct-bonded copper substrates. Furthermore, the dc-link capacitor is integrated onto the substrate such that typical connection elements are eliminated. The electrical design is verified with double-pulse measurements. To realize a high power density, the power module is cooled by an integrated micro-channel cooling structure. The cooling structure enables heat dissipation that most state-of-the-art power converters achieve only with double-sided cooling techniques. The addressed design elements are combined with an optimized inductor resulting in a synchronous boost dc-dc converter operated at a switching frequency of 333 kHz. Experimental results show that a maximum efficiency of 98.12 % at a maximum output power of 23.4 kW is achieved. This results in a power density of 70.9 kW / dm 3 .