| 摘要 |
PROBLEM TO BE SOLVED: To allow pin-point fault location, and suppress equipment cost of a fault location system itself.SOLUTION: Plural slave stations 1 record a difference value between zero-phase current detection values at a current time point and a time point before predetermined time, with time information in zero-phase current difference value recording means 15 for every predetermined time, record an accumulation value of the difference values in a period in which positive or negative difference values are continuously recorded in the zero-phase current difference value recording means 15, and when the accumulation value becomes equal to or more than a positive predetermined value or equal to or less than a negative predetermined value, extract a specific inflection point in the period in which the accumulation value is acquired, transmit the detection value and time information at the specific inflection point as surge detection value information and surge arrival time information. At a master station, based on transmission information from the plural slave stations 1, two pieces of surge arrival time information used for fault location are selected, and a position of the fault is calculated. |
