Crane Nuclear, Inc.

Electric Power Research Institute Incorporated

Liberty Technologies, Inc.

George Fox Lang

Martin Joseph Dowling

Louis Ricciuti, Jr

Binish Praful Desai

Robert L Leon

Glenn R Kahley

David O Heagerty

A method of detecting broken rotor bars including sensing currents applied to the motor, converting the senses signals to digital data signals, and storing the digital data signals. A processor evaluates the digital data to provide a current signal spectrum at various selected sidebands. Sideband peaks having an amplitude within a predetermined value are identified, indicating potential motor problems or developing problems, including winding faults and broken rotor bars. Advanced signal processing techniques are used to further evaluate stored data and to provide trending information.

Motor condition and performance analyzer

A motor performance analyzer senses currents and voltages applied to the motor, converts the sensed signals to digital data signals, and stores the digital data signals. The analyzer includes a processor for evaluating and comparing the digital data signals to predetermined values for voltage and current of the motor to determine and check for the correct placement of the current and voltage probes along corresponding phases of the motor. The analyzer also includes &lsqb;and&rsqb; a display for alerting a user or technician to potential motor problems, or to developing problems, including winding faults and broken rotor bars. &lsqb;Advanced signal processing techniques are used to further evaluate stored data and to provide trending information.&rsqb;

Method of monitoring placement of voltage/current probes on motors

A motor performance analyzer senses currents and voltages applied to the motor, converts the sensed signals to digital data signals, and stores the digital data signals. The analyzer includes a processor for evaluating the digital data and a display for alerting a user or technician to potential motor problems, or to developing problems, including winding faults and broken rotor bars. Advanced signal processing techniques are used to further evaluate stored data and to provide trending information.

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.

Method and apparatus for determining mechanical performance of polyphase

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.

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Lansdale, PA, United States of America

George Fox Lang