Testing of a Lightweight SiC Power Module for Avionic Applications

Abstract

Functional and performance tests of a three-phase, two-level power module based on CREE 1.2kV SiC MOSFETs for avionic applications is presented in this paper. SiC devices have superior properties over conventional Si devices at high voltage operations and these properties make SiC devices attractive for avionic industry in order to reduce size of power electronic converters while maintaining high efficiency. This paper starts with a brief explanation of thermo-mechanical design approach of SiC power module. Thermo-mechanical design is followed by test setup and experimental results for different load and switching frequency conditions. The module is tested up to 540V DC link voltage, 6kW output power with 100kHz switching frequency. Experimental results show that the module can be successfully operated with high efficiency at high switching frequencies.

A Physical RC Network Model for Electrothermal Analysis of a Multichip SiC Power Module

“…The result is presented in Fig. 12(b), and compared with the experimental result which was reported in the previous publications [1,2]. The estimated efficiencies of 1.2% to 2.1% higher can be ascribed to the following two facts.…”

“…They are actually better than the swinging amplitude approximately of 7 C which was predicted for the 50 Hz fundamental frequency related short-term thermal behavior of a Si IGBT-based wind power converter with switching frequency of 1950 Hz in the existing literature [40]. This result, together with the 95% to 98% efficiencies of the same SiC power module under the different switching frequencies which were tested in the previous publication [1], indicate that even under higher switching frequencies, the presently designed and developed much more compact and lighter SiC power module can achieve the thermal performance better than or similar to the conventional Si IGBT power modules. …”

“…As described in the previous publications [1,2], the three-phase half bridge, two-level SiC power module was designed for an avionic system where the input DC link voltage is 540V, full load is 6 kW, and output phase-to-neutral root mean square (RMS) voltage is 115 V with fundamental frequency of 50 Hz. The LTspice model was hence constructed based on the test setup for the full load of 6 kW as detailed in the previous publications [1,2]. Here the SPICE model of the SiC MOSFET was adopted from the model C2M0080120D provided by CREE, where only the in-built 6 RC thermal networks in the 6 MOSFETs were replaced by the present RC network model.…”

“…The values of RIJ can hence be used to calculate the worst rises of the average junction temperatures. For example, the SiC power module were tested to have the following worst power loss: 95% efficiency for 6 kW output power at switching frequency of 100 kHz [1]. This corresponds to 50 W heat generation from each of the 6 SiC MOSFETs.…”

“…In the present work, a threephase half bridge, two-level SiC power module based on CREE CPMF-1200-S080B Z-FET TM MOSFETs has been designed and developed specifically for avionic applications, where high gravimetric and volumetric power density and efficiency are highly desirable. In the previous publications [1,2], the design, fabrication and electrical test of the assembled module were reported. This paper is concerned with the thermal models for electro-thermal analysis of the assembled module using the finite element (FE) method and a physical compact RC thermal network.…”