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This paper presents a push-pull converter as a promising alternative to more complex and more costly isolated dc-dc converters for cost-sensitive, high-performance applications. The push-pull converter utilizes silicon carbide (SiC) power devices along with an active energy recovery clamp (AERC) circuit to extend the conventional operational limits of the topology. The SiC devices provide higher voltage blocking capability while maintaining low on-resistance as well as low switching energy. The AERC allows for nearly all of the energy stored in the leakage inductance of the transformer to be transferred back to the input capacitors without adding any control complexity to the system. The use of SiC devices along with the AERC allows for the push-pull converter to operate at a higher voltage, higher current, and higher switching frequency while maintaining high efficiency. In this work a prototype is developed to be operated with an input voltage of 400 V, a switching frequency of 200 kHz, and an output power greater than 5 kW. The performance of this prototype is compared to the same push-pull converter using an RCD clamp and significant improvements in efficiency are seen. The push-pull converter with AERC also shows higher efficiency across a wide range of output power conditions when compared to a soft-switching phase-shifted full-bridge (PSFB) converter with similar design specifications. Overall a maximum efficiency of 96.5% was measured at an output power of 3.7 kW for the push-pull converter with AERC.

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The complete design strategy (mechanical and electrical) of a three-phase 100 kW power converter utilizing silicon carbide (SiC) and silicon-on-insulator (SOI) electronics is presented. The design philosophy focuses on size reduction through high temperature operation (200+°C junction temperature). A low power, proof-of-concept prototype operating at 4 kW has been built and tested. The preliminary work renders the 100 kW module 75 % the size of comparable state-of-the art Si converters of the same voltage and power levels. The design approach makes use of the unique advantages of SiC devices while incorporating the necessary passive (capacitive and magnetic) technologies in order to complete a fully functional power module. High power density is obtained through high density integration of the control and power stages using multichip power module (MCPM) technology. The scaling of the low power module to the fully fledged three-phase 100 kW prototype SiC MCPM converter is analyzed in detail.

The demands of modern high-performance power electronics systems are rapidly surpassing the power density, efficiency, and reliability limitations defined by the intrinsic properties of silicon-based semiconductors. The advantages of silicon carbide (SiC) are well known, including high temperature operation, high voltage blocking capability, high speed switching, and high energy efficiency. In this discussion, APEI, Inc. presents two newly developed high performance SiC power modules for extreme environment systems and applications. These power modules are rated to 1200V, are operational at currents greater than 100A, can perform at temperatures in excess of 250 °C, and are designed to house various SiC devices, including MOSFETs, JFETs, or BJTs. One newly developed module is designed for high performance, ultra-high reliability systems such as aircraft and spacecraft, and features a hermetically sealed package with a ring seal technology capable of sustaining temperatures in excess of 400°C. The second module is designed for high performance commercial and industrial systems such as hybrid electric vehicles or renewable energy applications, implements a novel ultra-low parasitic packaging approach that enables high switching frequencies in excess of 100 kHz, and weighs in at just over 130 grams (offering ~5× mass reduction and ~3× size reduction in comparison with industry standard power brick packaging technology). It is configurable as either a half or full bridge converter. In this discussion, APEI, Inc. introduces these products and presents practical testing of each.