Station auxiliary power source apparatus

A station auxiliary power source apparatus that converts power supplied from an overhead cable to power to be supplied to a load in a station, the station auxiliary power source apparatus comprising:

• a control device including:
• a first calculator to calculate a plurality of first average values of an overhead cable voltage, wherein each of the plurality of first average values of the overhead cable voltage is calculated over a first predetermined period of time,
• a second calculator to calculate, over a second predetermined period of time, a second average value being an average value of values, from the calculated plurality of first average values of the overhead cable voltage, that are larger than an average value of the calculated plurality of first average values, and
• a third calculator to to calculate a third average value being an average value of the overhead cable voltage per day;
• and
• a comparator to select any one of the second average value and the third average value, and set the selected value as a threshold value,
• wherein the station auxiliary power source apparatus converts the power supplied from the overhead cable to the power to be supplied to the load when the overhead cable voltage is higher than the selected threshold value.