Abstract
Rods and plates at the connections in composite insulating material towers are commonly fixed to each other by metal bolts, which may cause electrical field distortion at the connections. So, the rod−plate connections are prone to partial discharge under polluted and wet conditions, and the resulting electric field and temperature changes can affect the mechanical and electrical performance of the whole tower. In this paper, an artificial pollution test synchronous observation platform with an infrared and visible light imager, leakage current, and voltage measurement was built to observe the dry band formation and partial discharge at the simplified rod−plate connections in the composite towers. Then, the electric field simulation of the rod−plate connection specimen showed the current density distribution. When combining the test and the simulation, it was concluded that the cause of the partial discharge was the distortion of the current density and, thus, measures to suppress the partial discharge at the rod−plate connections were proposed. Finally, it was verified that the measures can improve the current density distortion phenomenon, delay dry band formation, and effectively suppress the partial discharge at the rod−plate connections under the same test conditions.