带双侧隔离开关的新型12 kV开关柜研制

Research and Manufacture of a Novel 12 k V Switchgear with Two-side Disconnectors

为了解决手车移开式开关柜电场不均、隔离手车可靠性不易提升等问题,提出了一种新型空气绝缘金属封闭开关设备的设计方案,该方案集中了移开柜和固定柜的优点,它的主要特点是从柜前看三相主回路后中前纵向布置,主回路主要采用圆形导体,真空灭弧室两侧设有直动式隔离开关。对该方案的设计实现思路进行了分析,采用有限元方法对电场进行了仿真,结果显示该方案电场分布明显优于通常采用矩形铜排的开关柜。制造了采用该方案的12 kV/1250 A产品样机,并通过了全套试验,该样机达到了柜宽仅500 m、主导电回路缩短从而节约大量有色金属、整机局部放电量<10 pC的效果,实现了中压空气绝缘开关柜兼具小型化、双隔离和优异绝缘性能的特点,促进了中压开关柜的多元化发展。

In order to solve the problem of uneven electric field and poor reliability of the withdrawable switchgear.The paper presents a novel design scheme of the air insulation metal-enclosed switchgear,which combines the advantages of removable and fixed switchgears.Its main features are as follows:the three-phase main circuits are longitudinal layout from back to front if looking from the front of the cabinet,and the main circuit is mainly composed of circular conductors,with a linear moving disconnecting switch on each side of the vacuum interrupter.The reasons for this design and the ways to achieve it are discussed.The model’s electrical field is calculations by finite element method,the results show that its electric field is obviously superior to the switchgears which usually adopt rectangular conductors.A typical 12 kV/1250 A product prototype of this design is manufactured and tested.Its width is only500 mm.The partial discharge of the whole switchgearis less than 10 pC,and the main conductive circuit is greatly shortened,so a lot of material is saved accordingly.It is achieved that the switchgear combines the characteristics of miniaturization,with two-side disconnectors and excellent insulation performance,which promotes the diversified development of medium voltage switchgear.