71 / 2022-03-10 09:18:12

Test Method for Lightning Response of Real Transmission Lines

Lightning response,Test method,Transmission line

Lightning strike is one of the important factors that threaten the normal operation of transmission lines. Obtaining the lightning response characteristics can guide the lightning protect work of transmission lines, which is of great significance. The current research mainly analyzes related problems through equivalent circuit and numerical calculation of electromagnetic field. The results of theoretical analysis need to be verified by experiments. Existing experiments are mainly carried out on scaled models. However, the equivalence of scaled models requires further consideration. For the lightning response test of the real transmission line, there is no mature test method because of the high requirements of experimental conditions and the difficulty of operation. Therefore, a detailed study of the test method is required.

CDEGS is used to analyze the influence of the location selection of the refluxing electrode and voltage reference electrode on the test result. And the electromagnetic coupling between the various parts in the test loop is calculated. Based on the above results, this paper proposes a test method for the lightning strike response of a real transmission line, including the position selection of the refluxing electrode and voltage reference electrode, and the arrangement of the voltage wire and the current wire.

Combined with the calculation results and the operational feasibility of field test, the distance between the refluxing electrode and the measured tower is selected to be about 6 times the size of the tower grounding device. The voltage reference electrode is arranged on the other side of the tested tower, and the distance is also set to 6 times the size of the tower grounding device. The angle between the current wire and the tested transmission line is set to 90 degrees, while the angle between the voltage wire and the current wire is set to 180 degrees.

The proposed test method can effectively reduce the influence of the test loop on the test results. Using this method, the first lightning impulse test of 220kV transmission line in China was carried out. Ideal experimental results are obtained, which prove the feasibility of the proposed test method.