In partnership with the Laboratory for Electrical Machines (LEME) of the Swiss Federal Institute of Technology (EPFL) in Lausanne, Switzerland, PE has developed an innovative monitoring system capable of directly measuring the net electromagnetic force, also known as unbalanced magnetic pull (UMP), occuring between a synchronous generator's rotor and stator while in steady state operation.
All other monitoring systems available on the market today simply measure an electrical machine’s air gap variation. However, due to non-linear electromagnetic coupling between the rotor and stator there is no constant of proportionality between air gap variation and UMP, which explains why published air gap variation acceptance tolerances are presented as only approximate limiting values. In contrast, PE’s monitoring system not only quantifies the non-linear UMP in terms of force, but also establishes limiting force values for a specific unit by analyzing it’s structural characteristics and correlating UMP data with operating point over time.
PE's monitoring system allows Operators to obeserve trends, including whether or not a sudden shift in UMP magnitude and/or direction has occured, and assess the elctro magnetic health of the generators online without having to acquire relative proxies by measuring rotor and stator profiles periodically.Abstract (2 Pages)
- Low Cost Sensors
- Insensitivity to External Conditions (Humidity, Temperature, Etc.)
- Measurement of Static & Dynamic Induced Pull
- Capability to Recognize Deformation of Any Shape
- Arbitrary Position & Number of Sensors
- Real-Time Assessment of Air-Gap Condtion
- No Influence of Cables on the Measurement
- No Need for Linearization