Power Quality Assurance by using Integrated Power System

In recent years, new electricity supply systems have been constructed that benefit consumers and power supply enterprises, as the introduction of distributed power increases. This situation has led to new electric power network systems that supply multiple power quality levels to authorized consumers. As part of our research on demonstrating the supply of multiple power quality levels, we developed an integrated power system. We checked that the system can always supply high-quality electricity regardless of the condition of the AC upstream line and that it can assure the electricity quality of an AC upstream line when a distributed power supply is run independently. In addition, we built a DC distribution network and tried a DC 300 V distribution. DC distribution has conventionally been used for communication facilities at 48 V, but this voltage is too low to supply large-capacity electricity. Electric power can be distributed on a macro scale and distribution losses can be reduced by using a voltage of 300 V, but measures must be taken for safety. Therefore, we used a semiconductor switch in a protective device for DC 300 V distribution. We checked that it shorted the parallel circuit within about 1.0 mus of excess current being detected. We report the specifications and functions of the integrated power system and describe the DC protective device with a semiconductor switch