Peter Surland

Content
Hydro Monitoring Technics
Potential failure modes
Sensor location overview
Generator potential failure modes
Physical measurements
Adaptive monitoring strategy
Profile monitoring
Wind turbine Monitoring
Remote Monitoring
Conclusion to small generator monitoring
Hydro Monitoring Strategy: Techniques Available
Potential Failure Modes: Generator
•
•
Electrical
Thermal/Mechanical
Potential Failure Modes: Electrical
• Stator winding faults
• Shorted turns in the rotor
• Over-excitation
• Over-voltage
• Loss of field
• Unbalanced currents
• Abnormal frequency
Monitoring techniques:
• Air gap
• Magnetic flux
• PDA
• Vibration, SBV, core, windings
• Temperature
• Voltage, current
Potential Failure Modes: Thermal/Mechanical
• Overheating
• Uneven thermal expansion
• Misalignment
• Unbalance
• Defective rotor rim
• Stator/rotor deformation
• Loose stator hold-down bolts
• Wedge loosening
Monitoring techniques:
• Air gap
• Vibration, displacement
• Temperature
Air Gap and Magnetic Flux Sensor mounting
Stator
Air gap
Magnetic flux
Vibration Monitoring: Sensor Configuration-typical
Relative Shaft
Vibration
Absolute Case
Vibration
Upper Generator
Bearing
Lower Generator
Bearing
Thrust Bearing
Turbine Bearing
Failure modes: What can be detected with a smaller system?
Adaptive monitoring strategy: Machine state detection
Transient machine
states
Automatic detection of machine states
Adaptive monitoring strategy: The right measurement in the background
Adapted
measurements
Different machine states demand different
measurements
Adaptive monitoring strategy: Profile monitoring
Scalar Value
Standard Monitoring (scalar vs. time)
Overall
Alert High
Overall
Alert Low
Reference
Measured
Signal
Time
No Alarms
Generated
Profile Monitoring (scalar vs. rpm)
Scalar Value
Profile
Alert High
Reference
Profile
Alert Low
Measured
Signal
RPM
Alarms
Generated
Scalar values during run up – Limits varies with speed
Adaptive monitoring strategy: Profile monitoring
Shaft centerline during run up – Alarm limits vary with speed
Wind turbine monitoring
•
•
•
•
Monitoring with Vibration signatures
– Absolute casing LF & HF vibrasion
Rotor with Main bearings
– Rolling element bearing failures
– Shaft failures
– Gearbox failures
Generator bearing vibration
– Bearing and shaft failures
– Electrical failures
Process parameters
– Power
– Windspeed
– Ambient temperature
– Bearing temperature
Absolute Case
Vibration
Wind turbine monitoring
A wind turbine has a complex vibration pattern due to:
Continuously changing operational parameters
Low rotational speeds
Complex structure of the gearbox
Not rigid fundament
Very high and changing dynamic forces
Therefore a dedicated well tested vibration monitoring system
for the actual wind turbine application is needed
vibration vs. time
vibration vs. power
0,12
0,12
RMS 1 low
RMS 1 high
0,1
0,1
0,08
g rm
g rms
0,08
0,06
0,06
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
p
0
p
0,02
0
p
0,02
p
0,04
m
0,04
Conclusion
Monitoring principle for small power generators:
1. Vibration signatures are the most importent
2. Process parameters are needed for operating conditions
3. Remote monitoring is needed when the expert knowledge
is missing - especially for wind turbines
Thank You