SiC Based Modular Power Electronics for Fail-Safe Drive Technology
Semiconductors based on silicon carbide (SiC) promise higher power density and an increased efficiency. However, they are currently only rarely used in automotive drive inverters. The main drawbacks are the higher costs of the semiconductors and a complex packaging for effective cooling of the components. In the project SiCmodul, the partners AixControl, Bosch, Continental, Daimler, Fraunhofer IZM, Schweizer Electronic, TLK Thermo and ISEA are developing a new module design using PCB integrated SiC semiconductors. The module enables peak temperatures of the semiconductors of up to 200 °C, which allows a significant increase in power density. Additionally, the integration of the semiconductors leads to a longer lifetime of the module due to reduced thermal stress.
In SiCmodul, ISEA is developing a high-temperature gate driver as well as a current, voltage and temperature sensor. The gate driver contains a fast overcurrent detection, which ensures a safe turn-off of the power module in case of a fault. Furthermore, the chosen gate-driver topology enables a variable gate resistance. Thus, it provides the possibility to influence the switching process, e.g., to reduce the voltage slope at the phase outputs to increase lifetime of the winding insulation of the connected electrical machine.
The validation of the module design is carried out by the construction of a six phase traction inverter with a power of 160 kW. The converter is integrated into an asynchronous machine. The six phase design offers particular advantages in terms of redundancy. In the event of failure of a single module, the converter enables limp-home operation with reduced power.
First characterizations of the power module already show the high potential of the design with PCB-integrated SiC-MOSFETs. The commutation inductance was measured to be 1.7 nH, which is significantly lower than the inductance of commercially available SiC modules.
01st January 2018 – 31th December 2020