Development of Isolated Travel Sensor for High-voltage Switchgear

Because a contact travel can show a trend of operating condition of high voltage switchgears, it is utilized as an important parameter for not only monitoring or diagnostic system but also intelligent controls such as controlled switching systems to eliminate harmful switching transients. Potential meters or encoders are usually applied for this purpose, but it requires modification of moving parts that is not acceptable in some types of switchgears especially for retrofit work in fields.This paper describes a development of a compact and isolated type travel sensor, which can be easily installed in switchgear cabinets, and evaluation test results using prototype mounted in actual switchgear.