Abstract: The apparatus can be used for detecting a liquid contaminant in a rotating cavity of an electric machine. The apparatus can have a magnetic field source mounted to a non-rotary base and transmitting a magnetic field across a gap between the base a housing of the cavity, an interrogation circuit having a coil magnetically coupled to the magnetic field source across the gap via the magnetic field, and a distal circuit portion having electrical contacts separated by a spacing fluidly communicating with the cavity; and a detection circuit mounted to the base and having a coil magnetically coupled to the magnetic field and a detector detecting a variation occurring in the detection circuit upon change of a permittivity of the liquid across the spacing, the variation being indicative of the liquid contaminant.

Abstract: The capacitive sensor can have a sensing body having two flat conductor elements positioned parallel to one another and held spaced apart from one another, and having a thickness normal to the flat conductor elements, the sensing body having at least one aperture formed across its thickness. The capacitive sensor can be used to measure an air gap between a stator and rotor of a rotary electric machine, and the presence of the apertures can facilitate ventilation and/or improve linearization process of capacitive sensor through redistribution of its current vs distance signal along the measuring range, thus potentially increasing signal to noise ratio where it is the challenging to do so.

Abstract: Partial discharges in a high voltage electric machine can be monitored by a partial discharge monitor connected to the high voltage electric machine successively via a capacitive coupler and a connection cable. The connection cable can have a conductive element designed to self-destruct in the presence of electric current amplitude significantly exceeding expected current amplitudes from said partial discharges, and having diameter designed to avoid creation of additional partial discharges within the cable itself. The connection cable can be light enough to avoid adding excessive weight to the stator windings.

Abstract: The capacitive sensor can have a sensing body having two flat conductor elements positioned parallel to one another and held spaced apart from one another, and having a thickness normal to the flat conductor elements, the sensing body having at least one aperture formed across its thickness. The capacitive sensor can be used to measure an air gap between a stator and rotor of a rotary electric machine, and the presence of the apertures can facilitate ventilation and/or improve linearization process of capacitive sensor through redistribution of its current vs distance signal along the measuring range, thus potentially increasing signal to noise ratio where it is the challenging to do so.

Abstract: Partial discharges in a high voltage electric machine can be monitored by a partial discharge monitor connected to the high voltage electric machine successively via a capacitive coupler and a connection cable. The connection cable can have a conductive element designed to self-destruct in the presence of electric current amplitude significantly exceeding expected current amplitudes from said partial discharges, and having diameter designed to avoid creation of additional partial discharges within the cable itself. The connection cable can be light enough to avoid adding excessive weight to the stator windings.

Abstract: The method includes receiving a real-time signal containing information pertaining to amplitude and frequency of vibrations of a machine component over a frequency spectrum including a first analysis bandwidth and a second analysis bandwidth, and using the real-time signal to determine values indicative of the severity of vibrations occurring at frequencies in the first analysis bandwidth in a first unit of one of displacement, velocity, and acceleration, and determine values indicative of the severity of vibrations occurring at frequencies in the second analysis bandwidth in a second unit of one of displacement, velocity and acceleration, the second unit being different from the first unit; and associating the determined values in a common unit representing comparable severity of vibrations in the first analysis bandwidth and the second analysis bandwidth.

Abstract: The method includes receiving a real-time signal containing information pertaining to amplitude and frequency of vibrations of a machine component over a frequency spectrum including a first analysis bandwidth and a second analysis bandwidth, and using the real-time signal to determine values indicative of the severity of vibrations occurring at frequencies in the first analysis bandwidth in a first unit of one of displacement, velocity, and acceleration, and determine values indicative of the severity of vibrations occurring at frequencies in the second analysis bandwidth in a second unit of one of displacement, velocity and acceleration, the second unit being different from the first unit; and associating the determined values in a common unit representing comparable severity of vibrations in the first analysis bandwidth and the second analysis bandwidth.

Abstract: A monitoring system for rotor or stator shape changes detection of a rotating machine which can be used with an electric rotating machine with salient pole rotor. The system comprising: at least one gap measuring sensor affixed on the stator and producing real time measurements of gap thickness for each passing rotor reference point and associating the real time measurements to a unique identifier for each rotor reference point; a memory for storing reference values of gap thickness for each rotor reference point and each sensor position; a comparator for comparing corresponding ones of the real time measurements and the references values and identifying a positive or negative variation in the gap thickness greater than a predetermined minimum percentage; and a warning signal generator for emitting at least one warning signal.

Abstract: A method for detecting shorted turns in the windings of salient rotor poles of an electric rotating machine, the method comprising: for each one of the salient rotor poles, measuring a radial magnetic flux between a stator of the electric rotating machine and the salient rotor pole, and measuring a thickness of an air-gap between the stator and the salient rotor pole; for each one of the salient rotor poles, determining an expected radial flux using the measured radial magnetic flux and the measured thickness of the air-gap; and identifying shorted turns by comparing, for each one of the salient rotor poles, the measured radial magnetic flux to the expected radial magnetic flux.

Abstract: A temperature sensor, capable of operating in electromagnetic and/or electric environments such as electrical generators, motors and transformers and/or in environments where vibratory conditions are frequent or continuous, contains at least one light emitting optic fiber and one light receiving optic fiber and an electrically non-conductive dilatable object which variably occults the emitted light as the object's temperature varies. The light receiving optic fiber transmits light intensity and light intensity changes to an electronic device that may include a photometer and light-to-temperature computing equipment.

Abstract: A wireless breakage indicator for a shear pin having an axial bore. The indicator (10) comprises a stem (20) having a head (22) and a foot (24) at opposite ends thereof; a sleeve (32) around a portion of the stem between a first (28) and second (30) axial positions, the stem (20) and sleeve (32) adapted to be broken by the shear pin (12) in the event of its breakage; a spring (26) compressed between the head (22) of the stem (20) and a first end (34) of the sleeve (32); the foot (24) of the stem (20) being retained to the second end (36) of the sleeve (32). The breakage of the stem (20) frees the head (22) to be displaced by the spring (26) and indicate breakage of the shear pin (12). The indication can be direct, by visual inspection of the displaced head, or indirect by the displacement of the head activating a transmitter.

Abstract: A method for non-intrusive determination of an internal temperature of a given area of an electrical machine stator, comprises obtaining a temperature gradient between an internal wall of the stator and an external wall of the stator, obtaining temperature measurements at locations on the external wall of the stator, and using the temperature gradient and the external temperature measurements to extrapolate corresponding internal temperatures of the stator.

Abstract: A temperature sensor, capable of operating in electromagnetic and/or electric environments such as electrical generators, motors and transformers and/or in environments where vibratory conditions are frequent or continuous, contains at least one light emitting optic fiber and one light receiving optic fiber and an electrically non-conductive dilatable object which variably occults the emitted light as the object's temperature varies. The light receiving optic fiber transmits light intensity and light intensity changes to an electronic device that may include a photometer and light-to-temperature computing equipment.

Abstract: A wireless breakage indicator for a shear pin having an axial bore. The indicator (10) comprises a stem (20) having a head (22) and a foot (24) at opposite ends thereof; a sleeve (32) around a portion of the stem between a first (28) and second (30) axial positions, the stem (20) and sleeve (32) adapted to be broken by the shear pin (12) in the event of its breakage; a spring (26) compressed between the head (22) of the stem (20) and a first end (34) of the sleeve (32); the foot (24) of the stem (20) being retained to the second end (36) of the sleeve (32). The breakage of the stem (20) frees the head (22) to be displaced by the spring (26) and indicate breakage of the shear pin (12). The indication can be direct, by visual inspection of the displaced head, or indirect by the displacement of the head activating a transmitter.

Abstract: A method for non-intrusive determination of an internal temperature of a given area of an electrical machine stator, comprises obtaining a temperature gradient between an internal wall of the stator and an external wall of the stator, obtaining temperature measurements at locations on the external wall of the stator, and using the temperature gradient and the external temperature measurements to extrapolate corresponding internal temperatures of the stator.

Abstract: An optical acceleration sensor includes a target having a reflective portion and a non-reflective portion. A conveyor causes light to be irradiated on the target. A receiver receives light from the target. An inertial mass is coupled to at least one of the conveyor and the receiver, wherein movement of the inertial mass relative to the target causes a change in intensity of an amount of light impinging on the portions to change an amount of light received at the receiver. The conveyor and the receiver may be optical fibers and may be disposed at least partially in an opaque conduit and held substantially parallel in a sensor head.

Abstract: A non intrusive method and system for the dynamic measurement of a distance, or the variations over time thereof, constituting the thickness, or the variations thereof, of a thin compressible dielectric material located between one or several other closely spaced solid dielectric layers of constant thickness and a conductive or semi-conductive surface. This is achieved by positioning a capacitive sensor on the external layer of the dielectric material, the sensor being composed of two parallel plates electrically insulated from one another, feeding the first plate with a high frequency signal, measuring the voltage and current value over time generated by the high frequency signal between the plate of the sensor which is closest to the surface of the outer layer of dielectric material, and deducting the above distance or variations thereof.

Abstract: A non intrusive method and system for the dynamic measurement of a distance, or the variations over time thereof, constituting the thickness, or the variations thereof, of a thin compressible dielectric material located between one or several other closely spaced solid dielectric layers of constant thickness and a conductive or semi-conductive surface. This is achieved by positioning a capacitive sensor on the external layer of the dielectric material, the sensor being composed of two parallel plates electrically insulated from one another, feeding the first plate with a high frequency signal, measuring the voltage and current value over time generated by the high frequency signal between the plate of the sensor which is closest to the surface of the outer layer of dielectric material, and deducting the above distance or variations thereof.

Abstract: A method for dynamic and non-contact measurement of the displacement of a conductive substance with respect to a capacitive sensor formed by two parallel conductive plates, superimposed, electrically insulated from one another, and fed by a high frequency signal having a predetermined voltage, the capacitive sensor being connected to a device for detecting a current value. Also disclosed is a method for dynamic and non-contact measurement of the permittivity of a dielectric substance between a conductive part and a capacitive sensor of the above-mentioned type.

Abstract: A method for dynamic and non-contact measurement of the displacement of a conductive substance with respect to a capacitive sensor formed by two parallel conductive plates, superimposed, electrically insulated from one another, and fed by a high frequency signal having a predetermined voltage, the capacitive sensor being connected to a device for detecting a current value. Also disclosed is a method for dynamic and non-contact measurement of the permittivity of a dielectric substance between a conductive part and a capacitive sensor of the above-mentioned type.