Effect of breaking high voltage direct current (HVDC) circuit on demonstrative project on power supply systems by service level in Sendai

A High Voltage Direct Current (HVDC) system (300 V) was used for a Demonstrative Project on Power Supply Systems by Service Level in Sendai, Japan, entrusted by The New Energy and Industrial Technology Development Organization (NEDO). In high-quality DC power systems, the existing DC protection devices, such as the fuse and the Molded Case Circuit Breaker (MCCB), cannot conduct quick and stable circuit breaking. Therefore, we developed a semiconductor switch that uses a Metal Oxide Semiconductor-Field Effect Transistor (MOS-FET) as a new DC protection device. However, although it is possible to quickly break a HVDC circuit using this semiconductor switch, the possibility of a malfunction still exists because the semiconductor switch is an active device. Therefore, we included a retry function that repeats the turn on and turn off of the MOS-FET at certain periods, thus devising a method of evading malfunctions. We present the characteristics for breaking a HVDC circuit when a semiconductor switch is used as the HVDC protective device in the Demonstrative Project on Power Supply Systems by Service Level.