Power conversion device and method of determining operation state of interrupting unit

摘要

A power conversion device provided between a DC power supply and an AC electric path, the power conversion device including: a breaking device provided to at least one line of an output electric path in the power conversion device; a first voltage sensor configured to detect a voltage between lines of the output electric path, on a primary side of the breaking device; a second voltage sensor configured to detect a voltage between lines of the output electric path, on a secondary side of the breaking device; and a determination unit configured to calculate a primary-side voltage and a secondary-side voltage, and a primary-side phase and a secondary-side phase, on the basis of detection outputs from the first voltage sensor and the second voltage sensor, and determine 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.