Modern grid issues, old age and flex-ops has brought numerous new problems to the hydropower industry. One of these is generator rim float. Hydroelectric assemblies are rather stout and can run with minor float issues but as the problem worsens it can lead to an irregular air-gap, key fretting, accentuated magnetic forces between the rotor poles and the stator winding, fatigue, loss of rotor center, balance issues and further deterioration. Given the astronomical cost of unscheduled outages, plant operators need to know if they can keep running safely until the next scheduled outage.
Monitoring rim displacement relative to the spider is a great way to keep an eye on rim float as the problem progresses. Our new rim displacement sensor based on our strain and wireless power technology has the ability to detect displacement continuously with resolution down to 8nm. More than enough to detect changes in overall displacement that could be a sign of problems to come, giving operators the peace of mind they need to make it to the next scheduled outage.