Patent ID: 8751055

Claim:
A distributed power supply system comprising: a distributed power supply apparatus for supplying electric power to a customer load interactively with a commercial electric power utility; an internal load configured to be supplied with electric power from the commercial electric power utility; a current sensor for detecting a magnitude of a current and a direction of the current, the current being in a location closer to the commercial electric power utility than the internal load and the customer load; a controller; and a voltage detector for detecting a voltage of the electric power supplied from the commercial electric power supply utility to at least one of the internal load and the customer load, wherein: in a state where the distributed power supply apparatus is not generating the electric power, the controller: causes the internal load to actuate, performs determination control as to an installation state of the current sensor plural times based on a value detected by the current sensor, and performs the determination control in such a manner that at least one of plural intervals at which the determination control is performed is set to an interval other than an integral multiple of another interval of the plural intervals, in the determination control, the controller determines that the current sensor is abnormal when a deviation between an electric power value calculated from a value detected by the current sensor and a value detected by the voltage detector just before the internal load is actuated, and an electric power value calculated from a value detected by the current sensor and a value detected by the voltage detector just after the internal load is actuated, is not more than a first predetermined value which is a positive electric power value and is not less than a second predetermined value which is a negative electric power value, the controller determines that the current sensor is installed in an opposite direction when the electric power values are less than the second predetermined value, and the controller determines that the current sensor is installed in a correct direction when the electric power values are more than the first determined value.