Development of a rotor-mounted scanner for hydrogenerators. Final report

Technical Report · Tue Jun 01 04:00:00 EDT 1993

OSTI ID:10178558

Churchill, T L ^[1]

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1. STI Optronics, Bellevue, WA (United States)

An in situ, on-line, diagnostic and monitoring system has been developed for salient-pole hydroelectric generators. The system employs a distributed sensor array between two poles of the rotor to scan at close range the stator bore for signs of operational distress and two poles of the rotor to scan at degradation. Sensing includes thermal, RFI, magnetic, acoustic, air gap spacing, and rotor vibration. The system includes sensor array, on-rotor power conditioner (for tapping field power), bidirectional telemetry (for full-duplex command and data communications on and off rotor), twin fiber-optic link (to control room), system controller, and one or more personal workstations. As many as eight scanners can be operated from one system controller. Scanner development progressed from start (1985), to first demonstration (1987), to prototyping (1989), to commercialization (1991). At this writing, there are seven units in the field in machines ranging in capacity from 22 MVA to 450 MVA; three are pumped-storage units. The first scanner allowed the host utility to defer a $lM rewind for five years. The scanners have revealed various problems in their hosts ranging from plugged ventilation ducts ore hot spots, loose coils, and intense to uneven air gaps to poor distribution of cooling air. Core hot spots, loose coils, and intense RFI have been found. Functional benefits are full-time condition monitoring, in-depth diagnosis, and mitigation guidance during developing situations. Economic benefits off-setting installed costs include decreased costs by way of decreased maintenance frequency, avoidance of unplanned costs (including catastrophic repairs, lost revenues, and replacement power) through outage prevention, deferred costs through life extension, decreased repair costs by early warning of impending failure permitting advantageous outage scheduling, and increased revenues by improving machine operating efficiencies.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); STI Optronics, Bellevue, WA (United States)
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 10178558
• Report Number(s): EPRI-TR--102516; ON: UN93018810
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
130700
COST
ELECTRIC GENERATORS
FAILURES
HYDROELECTRIC POWER
MAINTENANCE
MEASURING INSTRUMENTS
MONITORING
POWER-CONVERSION SYSTEMS
ROTORS
STATORS