Method for diagnosing state of capacitor in modular converter

Abstract

The present invention relates to a method for diagnosing the state of the capacitor in a modular converter. The method for diagnosing the state of the capacitor in a modular converter includes determining a FIT table depending on the input voltage and temperature of an internal capacitor for multiple sample modular converters; detecting, by an input voltage detection unit, the input voltage of the capacitor in a target modular converter, the state of the capacitor of which is to be diagnosed, during a preset period; detecting, by a temperature detection unit, the temperature of the capacitor of the target modular converter during the preset period; calculating the cumulative mean for the input voltage and the temperature, which are respectively detected by the input voltage detection unit and the temperature detection unit during the preset period; and selecting, by a control unit, a FIT value corresponding to the cumulative mean of the input voltage and the temperature, from the FIT table; and extracting the MTBF of the capacitor from the FIT table.

Dependencies are inferred from the claim text.