水布垭电厂主变压器低压侧套管升高座法兰螺栓温度过热分析及处理

Analysis and Treatment of the Overheating of Flange Bolts in the Bushing Elevating Seat at Low Voltage Side of the Main Transformer in Shuibuya Hydropower Station

通过对水布垭电厂主变压器低压侧套管升高座法兰连接螺栓温度过热问题进行分析,提出在机组满发不停电状况下的临时处理方法及后续处理措施。先将法兰连接螺栓松动一部分,用大电流接地线将母线外壳与地短接。在原用的M12螺栓上穿套内径14 mm的黄腊管,采用制作的环氧绝缘垫片替换原有的金属垫片,将其中1颗螺栓连接上接地线,将升高座法兰与封闭母线外壳短接接地,从而消除悬浮电位,螺栓再未出现过热现象。待机组检修期间,将之前的临时措施拆除并恢复原设计方式,实践证明效果良好。

The abnormal overheating problem of flange connecting bolts in the bushing elevating seat at the low voltage side of the main transformer in Shuibuya Hydropower Station is analyzed. Temporary treatment measures for units under the full capacity operation condition and subsequent treatment measures are proposed. Firstly,partly loosening the flange connecting bolts and grounding the busbar case with large current grounding wires. Then,wearing PVC silicone fiberglass sleevings with 14 mm inner diameter on the original M12 bolts. Replacing the original metal spacers with the produced epoxy insulation spacers. Grounding the bushing elevating seat flange and the closed busbar case by connecting one of the bolts to the grounding wires. Thus,the suspension potentials are eliminated and the overheating problem of bolts is solved. During the unit maintenance,the temporary measures should be removed and the original designs be restored. Practice shows that the proposed treatment measures are effective.