Patent ID: 7586770

Claim:
An interconnection inverter device that includes an inverter for converting direct-current power of a direct-current power supply to alternating-current power to be supplied to an alternating-current power system, the interconnection inverter device comprising: a pair of buses including a positive bus that connects a positive terminal of the direct-current power supply to a positive terminal of the inverter and a negative bus that connects a negative terminal of the direct-current power supply to a negative terminal of the inverter; a pair of capacitors connected in series between the positive bus and the negative bus; a switch unit connected to any one of the positive bus and the negative bus; a pair of voltage monitor units each of which detects a terminal voltage of a corresponding one of the capacitors in the pair of capacitors; and a controller that controls the switch unit based on a terminal voltage detected by at least one of the voltage monitor units.