Method for detecting capacity leakage of capacitor in power conditioner, power conditioner performing the same, and photovoltaic power system provided with the same

A capacity leakage of a capacitor (18, 19) in a power conditioner (3) of a photovoltaic power system is detected to continue or stop running of the system according to a degree of the capacity leakage. A method according to an embodiment of the invention for detecting the capacity leakage of the capacitor is a method for detecting the capacity leakage of the capacitor in the power conditioner (3) that performs power conversion of an output of a photovoltaic cell (1) to output an output power to the system side. The method for detecting the capacity leakage of the capacitor includes the steps of: detecting that the capacity leakage exists based on a voltage deviation of a charge voltage between both ends of the capacitor of a detection target of the capacity leakage; suppressing the output power when the detected capacity leakage is a capacity leakage in which the running can be continued by the output power suppression: and stopping the running of the photovoltaic power system provided with the power conditioner when the capacity leakage is a capacity leakage in which the running of the system cannot be continued even if the output power is suppressed,