SYSTEM INTERCONNECTING DEVICE AND DECENTRALIZED POWER SUPPLY EQUIPPED WITH THE SAME AND HAVING INSTANTANEOUS VOLTAGE DROP PREVENTING FUNCTION

摘要

A system interconnecting device (21) is interposed between two power systems, such as a power receiving bus (22) for receiving electric power through a commercial power line (25) and a cogeneration bus (23) for receiving electric power from a private power generator (27). The device (21) is provided with thyristors (TH1 and TH2), diodes (D1 and D2), and a DC reactor (L). The thyristors (TH1 and TH2) are connected to the AC terminal (AC1), the diodes (D1 and D2) are connected to the AC terminals (AC2), the thyristor (TH1) and diode (D1) are connected to the DC terminal (DC1), and the thyristor (TH2) and the diode (D2) are connected to the DC terminal (DC2). The reactor (L) is connected between the DC terminals (DC1 and DC2). Therefore, when a fault occurs in a distribution line (26), the commercial power line (25), etc., power failure due to the overload of the power generator (27) can be prevented and instantaneous voltage drop in a distribution line (28) connected with an important load can be suppressed by the current limiting action of the reactor (L).