Design of Typical Insulation Structure for High-Voltage Converter Transformer Bushing

Abstract

This paper first analyzes the high-altitude operating environment of the ±500 kV converter transformer bushing, then based on this, further research is developed to quantitatively design the insulation structure inside the core of the converter sleeve. After experimental verification, the design scheme of the typical design of the ±500 kV converter transformer bushing is that the length of the zero-layer pole plate is 6762 mm, the diameter of the conductive rod is 100mm, the length of the N-layer pole plate is 1730 mm, and the diameter of the N-layer pole plate is 385 mm. A typical ±500 kV converter transformer has a carrying capacity of 3800 A on the central conductive rod of the bushing. Under a full wave lightning impulse voltage of 1950 kV, the maximum electric field strength of the SF6 gas atmosphere equalization device in the converter bushing is 9.92 kV/mm, and the maximum electric field strength on the surface of the equalization ball in the transformer oil is 1.48 kV/mm; at the rated operating voltage of 515 kV, the radial field strength of the converter bushing core is 5.8 kV/mm, and the axial field strength is 0.45 kV/mm, both of which satisfy the design requirements of the valve side converter bushing. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.