Investigation of a fast high-repetitive 10-kV SiC-MOSFET switching module

We report on the development of a 10-kV SiC MOSFET-based switching module, which can be easily scaled-up because of the principle of a serial connection of the SiC MOSFETs. In detail, the switching module consists of two circuit boards, each one featuring five Wolfspeed 1200-V C2M0080120D SiC MOSFETs, that are getting stacked in order to minimize the area of the current loop between high voltage and ground connector and as a result the inductance of the structure. The gate control of each SiC MOSFET is connected to a separate high-speed gate driver circuit, which is being triggered optically. The DC voltage supply of the components of each of the gate driver circuit is battery powered. As an overvoltage protection for the SiC MOSFETs and the optical receivers, the switching module uses transient voltage suppression (TVS) diodes. The turn-on time was experimentally determined to t
_on
= 21 ns at a switching voltage of V
_SW
= 10 kV and an average drain current of I
_D
= 38.5 A. A first successful test in burst-mode with a burst of 10 cycles at a pulse repetition frequency of f
_rep
= 5 MHz was carried out. Planned usage of gate-boosting techniques for a further speeding-up of the turn-on behavior will be discussed.