Epoxy Resin Bushings: The Seismic Defense Line For Ultra-high Voltage Power Grids

When a strong earthquake strikes, what equipment in a substation is most worrisome? The fracture of a towering bushing often triggers a chain reaction of accidents. Brittle fracture of porcelain bushings under seismic wave impact is not uncommon. The emergence of epoxy bushing is rewriting this situation.

Shaking Table Test: Safety Margins Behind the Data

In simulated earthquake shaking table tests for seismic resistance and reinforcement of engineering projects, researchers fixed the epoxy resin bushing bushing to the table with a rigid support and input artificial waves to test its seismic performance. When the acceleration amplitude in the three orthogonal directions at the flange approached 1.0g, the maximum measured stress at the bushing root flange was locked at 32.84 MPa, and the minimum safety factor reached 2.44. What does this number mean? It far exceeds the design specifications, providing ample safety margin for the power grid.

Finite element analysis of 550 kV multi-outgoing bushings also confirms this. Modal analysis was used to calculate the natural frequency, and the response spectrum of the static terminal tension, self-weight, and equivalent wind load were superimposed. The data showed that the calculated safety factor of this type epoxy resin cast bushing fully meets the requirements of the AG5 earthquake level.