Contribution of Xiao Yu

Topic: Design Considerations for Magnetic Coupling in Multi-phase Interleaved Boost Converter for Fuel Cell Application

Fuel cell systems as energy sources for vehicle drives require improvements in terms of their system costs, weight and volume in order to become attractive on the market. In particular, the reduction of volume and weight in the energy conversion chain from tank to drive represents a challenge, as these properties depend on the performance of the system. Innovative approaches are needed to solve this problem.

This study investigates different configurations for magnetic coupling in multiphase interleaved boost converters. Steady-state and Plec-based simulation models have been developed for different coupling configurations. The separation of AC and DC magnetic fluxes was considered to optimize the single components. Interactions between magnetic components and SiC MOSFETs were investigated. Methods were proposed to limit the design parameters and simplify system optimization. A scalable 40 kW two-phase boost converter with coupled inductors based on discrete SiC MOSFETs was built and tested

Contribution of Mahmoud Saeidi

Topic: Calibration and Thermal Characterization of Multi-Chip SiC Power Modules: Challenges and Approach

In many applications, compact design is highly favored but poses a significant challenge. This extends to semiconductor systems, aiming to reduce the size of power modules for both volume reduction and increased power density. However, compact sizing for power semiconductors leads to heightened power loss density and reduced heat dissipation capacity toward the cooling surface. Inadequate cooling measures, especially with reduced size, can result in escalated component temperatures. This work focuses on analyzing methods to dissipate losses from semiconductors and monitoring feasible temperature rises. The study specifically delves into the thermal properties of a power module. It is based on the NTC resistor RNTC mounted in the housing to estimate junction temperature, discusses pros and cons of employing the NTC resistor RNTC, conducts detailed RDS(on) measurements under various conditions and performs calibration of the voltage drop across the body diode for estimating junction temperature. The aim is to gain deeper insights into the thermal performance of the SiC multi-chip power module in a practical situation, involving a thermal simulation validated with practical results.

In addition, Dr. Siqi Lin presented his paper entitled: Design and Experimental Verification of an Oil-Cooled Medium-Frequency Transformer for a 250kW Half-Bridge Series Resonant Converter, which he wrote jointly with the University of Kassel and Fraunhofer IEE. Mr. Lin was supervised by Prof. Friebe during his time as a junior research group leader (Jun. Prof.) at Leibniz Universität Hannover, and he also completed his master's degree in electrical engineering in 2018 at the University of Kassel under Prof. Zacharias. We wish him much fun and success in his working life in the industry in his home country China.