Gas Research Institute

Csi Technology, Inc.

James R Stevenson

Stewart V Bowers, Iii

William E Childress

James F Kirkpatrick, Jr

A method monitors an operational condition of an electric motor, and stores in a memory device general trend, prognostic, diagnostic, and hazardous event information indicative of the motor's operational condition. The method includes the steps of sensing characteristics indicative of the operational condition of the electric motor, such as vibration, temperature, magnetic flux, and the voltages applied to the motor's windings, and generating sensor signals related to the sensed characteristics. Upon the occurrence of a first circumstance, such when measurements of the motor's speed, winding temperature, and voltage, indicate that the motor is operating within its normal load profile, prognostic information is extracted from the sensor signals. The prognostic information provides a profile of the motor's operational condition over time without the influences of fluctuating loads, temperature, and voltage. Upon the occurrence of a second circumstance, such as when the motor's load factor is within a load factor range that is most common for the motor, diagnostic information is extracted from the sensor signals. The diagnostic information indicates the motor's operational condition when it is operating within its most common load zone. Upon occurrence of a third circumstance, such as an indication that the motor is operating abnormally, hazardous event information is extracted from the sensor signals and stored. The hazardous event information indicates the motor's condition at the time that a hazardous event, or fault, occurred. The general trend information is measured and stored at regular intervals to determine short- and long-term operational trends over time.

Integrated electric motor monitor

Methods and apparatus employing optical spectrometry techniques to measure metallic wear debris contamination in used motor oil, even in the presence of carbon particulates. Measurement results based on optical spectrometry as disclosed herein correlate closely with results of laboratory analysis based on atomic spectrometry. Variation in transmittance of a sample of oil as a function of wavelength within the approximate range of 300 nm (violet) to 1300 nm (near-infrared) is measured as an indicator of metallic wear debris contamination. Conveniently, measurements may be taken at just two wavelengths within the range, for example 565 nm (green) and 660 nm (red). The ratio of transmittance at the shorter of the two wavelengths to transmittance at the longer of the two wavelengths is determined as an indication of the amount of metallic wear debris contamination, decreases in the ratio from a ratio of unity indicating increasing levels of contamination. Oil degradation not necessarily accompanied by metallic wear debris contamination may also be measured.

Growing community of inventors

Oak Ridge, TN, United States of America

James R Stevenson