High Speed Electronic Over Current Breaker for DC-Grids without Additional Sensing

An electronic over current breaker (OCB) for DC-grids without the need of additional sensing circuitry is presented. The OCB consists of standard Si-MOSFETs and is cascoded with SiC-JFETs for increased blocking capability. The over current detection threshold can be adjusted in a wide range. Due to the lack of additional sensing circuitry, the detection and clearing of a fault current is extremely fast and fail-safe compared to conventional OCBs at least with respect to the control.