Hybrid Circuit Breaker-based Fault Detection and Interruption in 380V DC Test-setup

AC technology has played a predominate role in electrical energy transmission and distribution. In future networks DC power could supply different applications like data centers, industry power etc. Hence, DC technology can introduce a key technology in order to fulfill the requirement of a reliable network in the future. However, different challenges in protection need to be faced. Especially the fault current rise time and amplitude in LVDC networks can reach critical conditions for the affected components. Furthermore, as future DC networks will contain distributed power generation a selective switch-off can be effective for a reliable operation of the network. For this reason, fast fault detection and selective fault clearing are recommended as serious component damages or network blackouts are possible. Thus, innovative developments for new DC switching devices as well as novel protection concepts are becoming increasingly important. In this research, a unit-based protection system was developed and implemented within a 380 V DC test-setup. Moreover, a self-established hybrid circuit breaker was used to interrupt the current. Here, the hybrid circuit breaker receives switching commands from the FPGA-based protection unit which continuously monitors the network. Current and voltage are measured at the hybrid circuit breaker and then commuted to digital signals via I/O-modules in order to be sent to the FPGA. This data will be processed by the protection algorithm. Based on that, specific protection criteria for fault detection, characterization, localization and selective fault clearing have been implemented here.