Abstract: Methods and systems detect short circuits in an electrical system, such as a dynamic braking grid of a vehicle. The methods and system measure a characteristic of a current that is conducted through one or more resistive elements of an electrical system. The current is supplied to the electrical system from a power source as an applied voltage. A resistance change signal representative of a change in one or more electrical resistances of the one or more resistive elements is determined The resistance change signal can be based at least in part on a difference between the characteristic of the current that is measured and a low pass filtered value of one or more of the characteristic of the current that is measured or the applied voltage supplied by the power source. A short circuit event is identified based at least in part on the resistance change signal.

Abstract: Systems and methods are disclosed for on-line monitoring of the condition of the stator insulation of an AC motor or an electric generator. In certain embodiments, the system includes a transformer surrounding each pair of input and output cables associated with a given phase of power provided to the AC motor or generated by the electric generator. In another embodiment, a transformer surrounds the three input cables (for an AC motor) or the three output cables (for an electric generator) that correspond to phases of the AC motor or electric generator. In both embodiments, the transformers generate voltages that may be used to monitor leakage currents associated with the cables. A microcontroller monitors the voltages generated by the transformers and determines the condition of the stator insulation of the AC motor or the electric generator based on the voltages.

Abstract: The subject matter herein generally relates to electrical generators and motors, and more specifically, to electrical turbo-generators. In an embodiment, an electrical system includes a circuit. The circuit includes one or more rotating power delivery assemblies comprising a plurality of sliding surfaces that deliver power to a rotating load. The circuit also includes one or more radio frequency current transformers (RFCTs) that measure radio frequency (RF) signals corresponding to arcing events in the one or more rotating power delivery assemblies. The electrical system also includes a processor that receives the measurements from the one or more RFCTs and determines a health value of the circuit based, at least in part, on the received measurements.

Abstract: A collector monitoring system is disclosed. In one embodiment, the collector monitoring system includes: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of a dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

Abstract: A method of detecting faults in a wind turbine generator based on current signature analysis is disclosed herein. The method includes acquiring a set of electrical signals representative of an operating condition of a generator. Further, the electrical signals are processed to generate a normalized spectrum of electrical signals. A fault related to a gearbox or bearing or any other component associated with the generator is detected based on analyzing the current spectrum.

Abstract: A current transformer is provided. The current transformer comprises an inner magnetic core having a central opening, an outer sense core circumscribing the inner magnetic core, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the inner magnetic core, and one or more coils disposed on the inner magnetic core, the outer sense core, or both, in a magnetically balanced configuration relative to a magnetic neutral axis of the inner magnetic core.

Abstract: Systems and methods are disclosed for on-line monitoring of the condition of the stator insulation of an AC motor or an electric generator. In certain embodiments, the system includes a transformer surrounding each pair of input and output cables associated with a given phase of power provided to the AC motor or generated by the electric generator. In another embodiment, a transformer surrounds the three input cables (for an AC motor) or the three output cables (for an electric generator) that correspond to phases of the AC motor or electric generator. In both embodiments, the transformers generate voltages that may be used to monitor leakage currents associated with the cables. A microcontroller monitors the voltages generated by the transformers and determines the condition of the stator insulation of the AC motor or the electric generator based on the voltages.

Abstract: A current transformer is provided.

Abstract: A partial discharge analysis (PDA) coupling device is provided. In one embodiment, a device includes: a connector electrically connecting a first coupling capacitor and a second coupling capacitor; a first conductive rod for electrically connecting the first coupling capacitor to a high voltage input; a second conductive rod for electrically connecting the second coupling capacitor to ground; a current transformer substantially surrounding a portion of the second conductive rod, the current transformer configured to generate a pulse signal; and a reference signal generator adjacent to the current transformer configured to generate a reference signal in phase with the pulse signal.

Abstract: A current transformer assembly for use in an electrical monitoring system is described herein. The current transformer assembly includes a housing including a plurality of shielding members that at least partially define a cavity therein. The housing further includes an inner surface that defines an opening that extends therethough. A first current transformer is positioned within the housing. A second current transformer is positioned within the housing and is spaced a distance from the first current transformer to facilitate reducing electronic noise interference between the first and second current transformers.

Abstract: A collector monitoring system is disclosed. In one embodiment, the collector monitoring system includes: a sensor connected to an interior surface of a dynamoelectric machine housing, the sensor for sensing a condition of a collector during operation of a dynamoelectric machine; and a diagnostic system operably connected to the sensor, the diagnostic system configured to: obtain data about the condition of the collector from the sensor; compare the data about the condition of the collector with a predetermined condition threshold; and provide an indicator of a collector fault in response to the data about the condition of the collector exceeding the predetermined condition threshold.

Abstract: A method of monitoring a capacitor bank comprising a plurality of capacitor strings connected in parallel, each capacitor string comprising a plurality of capacitors connected in series is provided. The method includes energizing the capacitor bank. The method includes determining dissipation factors of each of the plurality of the capacitor strings. The method further includes comparing each of the determined dissipation factors with an expected dissipation factor and estimating a health state of the plurality of the capacitor strings based, at least in part, on the comparison of the determined and expected dissipation factors.

Abstract: A current transformer is provided. The current transformer comprises an inner magnetic core having a central opening, an outer sense core circumscribing the inner magnetic core, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the inner magnetic core, and one or more coils disposed on the inner magnetic core, the outer sense core, or both, in a magnetically balanced configuration relative to a magnetic neutral axis of the inner magnetic core.

Abstract: An electrostatic filter assembly configured to be installed in equipment for removing particulate matter entrained within a gas stream. The filter assembly functions in the removal and collection of the particulate matter from the gas stream. The equipment for removing particulate matter includes a high voltage discharge electrode for imparting an electric charge to the particulate matter whereby an electrical field is produced at the filter assembly. The filter assembly includes a filter element and a supporting structure for the filter element. The supporting structure is configured to establish at the filter assembly, under the operating conditions of the equipment for removing particulate matter, an electrical field having an intensity that produces no more than a selected amount of degradation at the filter element during operation of the equipment for removing particulate matter. Also a method of manufacturing such an electrostatic filter assembly.

Abstract: A current transformer assembly for use in an electrical monitoring system is described herein. The current transformer assembly includes a housing including a plurality of shielding members that at least partially define a cavity therein. The housing further includes an inner surface that defines an opening that extends therethough. A first current transformer is positioned within the housing. A second current transformer is positioned within the housing and is spaced a distance from the first current transformer to facilitate reducing electronic noise interference between the first and second current transformers.

Abstract: The subject matter herein generally relates to electrical generators and motors, and more specifically, to electrical turbo-generators. In an embodiment, an electrical system includes a circuit. The circuit includes one or more rotating power delivery assemblies comprising a plurality of sliding surfaces that deliver power to a rotating load. The circuit also includes one or more radio frequency current transformers (RFCTs) that measure radio frequency (RF) signals corresponding to arcing events in the one or more rotating power delivery assemblies. The electrical system also includes a processor that receives the measurements from the one or more RFCTs and determines a health value of the circuit based, at least in part, on the received measurements.

Abstract: A method of detecting faults in a wind turbine generator based on current signature analysis is disclosed herein. The method includes acquiring a set of electrical signals representative of an operating condition of a generator. Further, the electrical signals are processed to generate a normalized spectrum of electrical signals. A fault related to a gearbox or bearing or any other component associated with the generator is detected based on analyzing the current spectrum.

Abstract: A partial discharge analysis (PDA) coupling device is provided. In one embodiment, a device includes: a connector electrically connecting a first coupling capacitor and a second coupling capacitor; a first conductive rod for electrically connecting the first coupling capacitor to a high voltage input; a second conductive rod for electrically connecting the second coupling capacitor to ground; a current transformer substantially surrounding a portion of the second conductive rod, the current transformer configured to generate a pulse signal; and a reference signal generator adjacent to the current transformer configured to generate a reference signal in phase with the pulse signal.

Abstract: A current transformer is provided. The current transformer includes a magnetic core having a central opening, at least one pair of conductors extending through the central opening and positioned symmetrically with respect to a center point of the magnetic core, one or more coils disposed on the magnetic core along a magnetic neutral axis of the magnetic core and one or more coils disposed on the magnetic core along a reference axis, wherein the reference axis is substantially perpendicular to the magnetic neutral axis.

Abstract: An electrostatic filter assembly configured to be installed in equipment for removing particulate matter entrained within a gas stream. The filter assembly functions in the removal and collection of the particulate matter from the gas stream. The equipment for removing particulate matter includes a high voltage discharge electrode for imparting an electric charge to the particulate matter whereby an electrical field is produced at the filter assembly. The filter assembly includes a filter element and a supporting structure for the filter element. The supporting structure is configured to establish at the filter assembly, under the operating conditions of the equipment for removing particulate matter, an electrical field having an intensity that produces no more than a selected amount of degradation at the filter element during operation of the equipment for removing particulate matter. Also a method of manufacturing such an electrostatic filter assembly.