Short-Circuit Point Estimation Method Using Abnormal Detection Line of Distribution Line

Short-circuit accidents hinder the supply of electric power in distribution lines. If a short-circuit occurs, the power supply is interrupted and can be resumed only after the short-circuit point is repaired. Identifying the short-circuit point is time consuming because it is necessary to confirm whether the overcurrent passage indicator is operating and visually confirm the short-circuit point. Therefore, we propose a method of installing an abnormal detection line under the high-voltage line and identifying the short-circuit point based on the current ratio before and after the short-circuit flowing to the current-measuring devices installed at both ends of the abnormal detection line. Because the current flowing in a high-voltage distribution line at the time of the short-circuit depends on the short-circuit resistance value, the range of application of the short-circuit resistance value is also discussed. We show that the method using abnormal-detection lines can be applied to estimate the high-resistance ground faults and disconnection points, and the ability to estimate short-circuit points leads to the efficient use of the method using abnormal detection lines.