Optimization of 550 kV GIL Spring Contact Finger Structure Based on Electro-thermal Coupling Analysis

In order to improve the structural performance of the GIL contact finger, this paper takes the 550 kV GIL spring contact finger as the research object, explores its temperature distribution law under the rated current of 5500 A, and combines the dung-beetle optimization algorithm with the optimization scheme of the spring contact finger structure. Through the electro-thermal coupling analysis, it is found that the contact temperature rise of the contact finger decreases proportionally with the increase of the spring wire diameter, the number of spring coils, and the inclination angle of the single-coil spring, and the spring mid-diameter is too large or too small, which will increase the temperature rise of the contact finger, and the angle of the contact seat V-groove has a small influence on the temperature rise. Optimization results demonstrate that the selected spring finger structure parameters include a spring wire diameter (d) of 2 mm, a spring mid-diameter (& Fcy;) of 133 mm, 147 coils (n) for the spring, a single-coil spring tilt angle (alpha) of 60 degrees, and a contact seat V-groove angle (beta) of 120 degrees, resulting in a temperature rise of the finger of 47.57 K, indicating effective optimization.