Evaluation of Extra High Voltage (XHV) Power Module for Gen3 10 kV SiC MOSFETs in a Mobile Utility Support Equipment based Solid State Transformer (MUSE-SST)

MV solid state transformers enabled by SiC semi-conductor devices is a promising replacement to conventional low frequency transformers. However, when MV SiC devices are used in converter applications, they are exposed to a high peak stress (5 kV to 10 kV) and a very high dvldt (10 kV/mu s to 100 kV/mu s). Operating these semiconductor devices at these high peak stresses require careful designing from the packaging point of view, as well as designing the auxiliary systems such as the gate drivers and busbars, to handle the peak stress conditions. Recently, an extra high voltage (XHV) power module has been developed by Wolfspeed to package the 10 kV SiC MOSFETs for continuous and reliable operation. This paper aims at testing these modules in continuous operation for qualifying their operation in a MV solid state transformer. Reliable operation of these modules require the development of reliable auxiliary parts including gate drivers, bus bars and inductors. Design and development of the auxiliary system is also carried out. Successful tests demonstrating operation at MV levels are also shown. These tests serve as a qualification method for using these devices in a MV solid state transformer. It is envisaged that successful operation of these devices would accelerate the growth and deployment of MV SiC devices for field operation.