694 / 2022-03-31 15:48:40

Development Tool Chain of Compact GIS Spacer Utilizing Novel Design and Fabrication Methods

Gas Insulated Switchgear,Solid Insulation,Optimization Design,3D Printing,Functionally Graded Material

Purpose/Aim

Gas insulated switchgear (GIS) are world-widely used in electrical power transmission systems due to its high reliability, small space consumption and low electromagnetic interference. To facilitate the reduction of SF6 gas usage, the material cost and space requirement, compact design of GIS devices is urgently required. Unfortunately, solid spacers in GIS devices suffers from largely lowered breakdown (flashover) voltage at the gas-solid interfacial area, which significantly restricts hinders the further miniaturization of GIS devices.

Experimental/Modeling methods

In this paper, a development tool chain for design, prototyping and end-use of compact GIS spacer is proposed, which contains numerical optimization methods for the design phase, rapid fabrication methods for the prototyping phase, and the batch fabrication method for the end-use phase. Firstly, the concept of geometrical optimization and functionally graded materials is combined to design compact GIS spacers with significantly improved surface electric field distribution. Then, hollow-structure 3D printing is integrated with vacuum infilling to build downsized (10:1) prototyping spacers with both optimized structure and permittivity gradients, whose improvement in surface flashover voltage is verified experimentally. Finally, the fabrication of end-use, actual-size compact GIS spacer is successfully conducted by a two-step method combining 3D printing and vacuum casting.

Results/discussion

As for the 10:1 prototype of compact 550kV GIS spacer, the surface insulation performance is improved by 13.6% under 0.2MPa SF6 gas. When 15% reduction in insulation distance is employed, the compact 550kV GIS spacer remains the same insulation strength, confirming the effectiveness of proposed development methods and can lead to >20% reduction of SF₆ gas.

Conclusions

This paper proposes a set of design and fabrication method for the compact GIS spacers, which covers the whole design-prototyping-production phases. We believe that the proposed tool chain can significantly facilitate the development of advanced solid insulation parts for GIS devices, promoting its further performance enhancement as well as geometrical downsizing.