Live-Line Detection of Deteriorated Insulators on Overhead Transmission Lines Based on Electric Field Distribution

The presence of deteriorated insulators in power grids poses a significant threat to the safety of power transmission. The electric field detection method (EFDM) is considered an effective approach for detecting low or zero value insulators on high-voltage transmission lines. In this article, we analyzed the effects of the detection device, measurement angle, and insulator deterioration on the axial electric field value of insulator strings using both test values and simulation values. Our results indicated that the detection device had minimal impact on the normalized values of the axial electric field, whereas the measurement angle affected the values. However, the errors between the test values and the simulation values at the ends of the insulator strings were larger, indicating that the measurement device is better suited for measuring at nonends of the insulator strings. Based on our findings, we used the detection device to measure the electric field of insulator strings on a 220-kV transmission line. The results of the measurement showed that the electric field detector could accurately measure the axial electric field of the insulator string and detect deteriorated insulators, thereby providing a more effective measurement method. Our research thus confirms the feasibility of the EFDM in actual power transmission lines.