真空开关选相操作特性在线检测消除电感性电流开断的操作过电压

On-line Detection of Phase Selection Operation Performance of Vacuum Switch for Switching Overvoltage with Elimination of Inductive Current Interruption

真空开关开断电感性负载时,电弧重燃是产生严重操作过电压的根本原因。真空开关选相操作可以消除电弧重燃,避免严重的操作过电压。选相真空开关的机械稳定性是保证可靠选相操作的关键,对选相真空开关的机械稳定性进行在线检测,可及时发现和避免选相失效。文中提出两种选相特性在线检测方法:在选相真空开关的操动机构上设置一个和主触头动作稳定同步的辅助接点,用于触头刚分时刻的信号传感,可实现选相特性的在线检测和选相操作的自适应控制,及时发现选相特性劣化,避免选相失效;通过检测真空开关开断过程中的空间电磁波,识别电弧重燃产生的电磁波脉冲,可以实现电弧重燃的在线检测,及时发现选相失效。

In case of interrupting inductive load by vacuum switch,re-ignition of arc is the root cause of generating serious switching over-voltage.Phase selection operation of vacuum switch can effectively eliminate the re-ignition of arc and avoid the serious switching over-voltage.The mechanical reliability of phase selection of vacuum switch is the key in assuring the reliable phase selection operation.On-line detection of mechanical stability of the phase selection of vacuum switch can find timely and avoid invalid phase selection.In this paper,two kinds of on-line detection methods of phase selection characteristic are proposed.One auxiliary contact with stable and simultaneous operation with the main contact is set on the operating mechanism of the phase selection vacuum switch for the signal sensing at the instant opening of the contact,which can achieve the on-line detection of phase selection characteristic and adaptive control of phase selection operation,find timely deterioration of phase selection characteristic and avoid invalid phase selection.The electromagnetic pulse due to re-ignition of arc is identified through detecting space electromagnetic wave of vacuum switch during the interruption period so to achieve on-line detection of re-ignition of arc and find timely invalid phase selection.