Abstract: A power conversion device provided between a DC power supply and an AC electric path, including: a breaking device provided to at least one line of an output electric path in the power conversion device; a first voltage sensor provided on a primary side of the breaking device; a second voltage sensor provided on a secondary side of the breaking device; and a determination unit which calculates a primary-side voltage and a secondary-side voltage, and a primary-side phase and a secondary-side phase and determines that the breaking device is opened, by occurrence of an event in which an absolute value of a voltage difference between the primary-side voltage and the secondary-side voltage is greater than a voltage difference threshold value and an absolute value of a phase difference between the primary-side phase and the secondary-side phase is greater than a phase difference threshold value.

Abstract: A power conversion device provided between a DC power supply and an AC electric path, including: a breaking device provided to at least one line of an output electric path in the power conversion device; a first voltage sensor provided on a primary side of the breaking device; a second voltage sensor provided on a secondary side of the breaking device; and a determination unit which calculates a primary-side voltage and a secondary-side voltage, and a primary-side phase and a secondary-side phase and determines that the breaking device is opened, by occurrence of an event in which an absolute value of a voltage difference between the primary-side voltage and the secondary-side voltage is greater than a voltage difference threshold value and an absolute value of a phase difference between the primary-side phase and the secondary-side phase is greater than a phase difference threshold value

Abstract: This concentrator photovoltaic system includes: a concentrator photovoltaic panel; a driving device configured to cause the concentrator photovoltaic panel to perform periodical tracking operation with respect to the sun in two axes of azimuth and elevation; a measurement section configured to detect generated power or generated current as an amount of generated electricity of the concentrator photovoltaic panel; and a control section configured to obtain, when the driving device has caused the concentrator photovoltaic panel to perform tracking operation in either one of the two axes, a change in the amount of generated electricity of the concentrator photovoltaic panel before and after the tracking operation, the control section configured to determine presence/absence of tracking deviation that should be corrected, based on the change.