Abstract: The porcelain bushing above 2.5m is usually fired in sections, and the cross-section is mechanically treated to form a “V” shaped interface. Then, the upper, middle and lower single sections are integrally fired and connected with inorganic adhesive glaze at high temperature. The adhesive glaze and each section of the porcelain bushing melt and penetrate into each other to form a whole porcelain bushing. After the overall firing is completed, its mechanical and electromechanical properties shall be verified by visual inspection, dimensional inspection, ultrasonic flaw detection, high and low temperature cycle test, internal pressure load test and bending load test. This paper analyzes the reasons for the breaking (bursting) of the sectioned porcelain bushing of 500kV SF₆ circuit breaker, comprehensively analyzes and demonstrates various factors affecting the electromechanical performance of the porcelain bushing of SF₆ tank circuit breaker through the disassembly inspection and test detection of the porcelain bushing, and puts forward strategies and measures to improve the process quality of the porcelain bushing and ensure the performance of the porcelain bushing, which provides references for the scientific design and safe operation of SF₆ tank circuit breaker.

Key words: SF₆ gas insulation, circuit breaker, ceramic sleeve, mechanical strength, V-shaped interface

摘要： 2.5m以上的瓷套管通常分节烧制,经断面机械处理形成“V”形接口,再将上中下各单节采用无机粘接釉整体高温烧制连接,粘接釉与瓷套各分节互相熔融渗透,形成整支瓷套管。整体烧制完成后,应通过外观检查、尺寸检查、超声波探伤检查以及高低温循环试验、内压负荷试验和弯曲负荷试验等验证其机械及机电性能。文中分析了500kV SF₆断路器分节瓷套断(炸)裂原因,通过对瓷套管解体检查和试验检测,对影响SF₆罐式断路器瓷套管机电性能的各类因素进行全面分析论证,提出改善瓷套管工序质量、保证瓷套管性能的策略和措施,为SF₆罐式断路器科学设计和安全运行提供借鉴。

关键词: SF₆气体绝缘, 断路器, 瓷套管, 机械强度, “V”形接口