An Online Early-Warning Method for Wind Swing Discharge of the Conductor Toward the Tangent Tower and Jumper Toward the Strain Tower

In recent years, accidents involving wind swing discharge occur on transmission lines frequently, and have affected the operational security and the power-supply reliability seriously. Since the preventive measures for wind swing discharge are expensive and difficult to implement and other factors, it is hard to avoid the trip-out accidents due to wind swing discharge. Therefore, an online early-warning method based on meteorological information for wind swing discharge is proposed from the perspective of operation. Starting with the side-phase conductor of the tangent tower and jumper of strain tower, which are common and prone to raise accidents of wind swing discharge and based on meteorological forecasting information, the wind swing angle of the suspension insulator string is calculated, then the minimum air gap between line and tower is determined through introducing a 2-D Descartes coordinate system into the tower model. At last, the comparison with designed minimum air gap is conducted to obtain warning results and release warning information. Moreover, considering the rainfall will reduce the discharge voltage of the air gap, a correction factor of rainfall is introduced to revise the designed minimum air gap to make the warning more accurate Finally, the feasibility and accuracy of the proposed method are verified by sample analysis.