George J Lang

US Patent:

54718805, Dec 5, 1995

Filed:

Apr 28, 1994

Appl. No.:

8/234192

Inventors:

George F. Lang - Lansdale PA
Robert L. Leon - Maple Glen PA

Assignee:

Electric Power Research Institute - Palo Alto CA

International Classification:

G01N 2912

US Classification:

73660

Abstract:

An improved method and apparatus for detecting and identifying one or more resonantly vibrating blades of a turbine through the use of acoustic sensors imbedded in the stationary casing of the turbine is disclosed. The acoustic sensor signals are processed to separate the characteristic Doppler waveform from the accompanying random noise and periodic noise. Improved signal processing techniques which involve the evaluation of both an information-bearing resonant signal and its Hilbert transform via direct synthesis are disclosed.

US Patent:

55214827, May 28, 1996

Filed:

Aug 22, 1994

Appl. No.:

8/293986

Inventors:

George F. Lang - Lansdale PA
David O. Heagerty - Glenn Mills PA
Glenn R. Kahley - Millville NJ

Assignee:

Liberty Technologies, Inc. - Conshohocken PA

International Classification:

H02P 900

US Classification:

318800

Abstract:

A method for determining electrical and mechanical performance of a polyphase electric motor system comprises sensing the instantaneous current signal and the instantaneous voltage signal as a function of time for at least one electrical phase of the motor. The sensed current signals and the sensed voltage signals are both processed to provide an instantaneous power factor of at least one electrical phase of the motor as a function of time. The resulting power factor is used to determine the tonal real and the total reactive power of the motor as a function of time. The total real power and the total reactive power signals are bandwidth limited and time-limited. The filtered and time-limited, total real power is then cross-plotted as a function of the filtered and time limited, total reactive power signal, generating a performance diagram. The mechanical performance characteristics of the motor are then extrapolated from the performance diagram.