Abstract: Embodiments test MOV arresters. One embodiment comprises applying a plurality of voltages to a high voltage lead of the MOV arrester, the plurality of voltages being changed between an initial test voltage and final test voltage (corresponding to a point of conduction of a reference MOV arrester); determining a resistive current through the MOV arrester for each of the voltages; determining information corresponding to the resistive current when the applied test voltage corresponds to the point of conduction of the reference MOV arrester; comparing the determined information with information associated with the point of conduction of the reference MOV arrester; determining that the MOV arrester has passed the test when the determined information corresponds to the information associated with the reference MOV arrester; and determining that the MOV arrester has failed the test when the determined information does not correspond to the information associated with the reference MOV arrester.

Abstract: A system and method for testing polymer insulators is provided. One embodiment includes applying a voltage to a grading shield that is oriented about a top region of a polymer insulator and to a high voltage lead of the polymer insulator; detecting a leakage current across the polymer insulator; determining a resistive current component from the detected leakage current; comparing the resistive current component to a predefined criteria; determining that when the resistive current component is greater than the predefined criteria when the applied voltage is applied, the polymer insulator has failed the test; and determining that when the resistive current component is less than or equal to the predefined criteria when the applied voltage is applied, the polymer insulator has passed the test.

Abstract: The winding testing unit provides systems and methods for determining normal and/or abnormal characteristic signatures of same-voltage windings residing in a device, such as transformer, without the need for a comparison to past historical data. A plurality of characteristic signatures [H(f)'s] are determined for each of a plurality of windings. A plurality of differential characteristic signatures [H(f)'s] are then determined from a plurality of H(f) pairs selected from the plurality of H(f)'s. The differential H(f)'s are compared and at least one significant asymmetry is identified between the differential H(f)'s.

Abstract: The winding testing unit provides systems and methods for determining normal and/or abnormal characteristic signatures of same-voltage windings residing in a device, such as transformer, without the need for a comparison to past historical data. A plurality of characteristic signatures [H(f)'s] are determined for each of a plurality of windings. A plurality of differential characteristic signatures [H(f)'s] are then determined from a plurality of H(f) pairs selected from the plurality of H(f)'s. The differential H(f)'s are compared and at least one significant asymmetry is identified between the differential H(f)'s.

Abstract: The on-line winding test unit determines a characteristic signature of a monitored winding(s) in a transformer, generator, or the like. A sensor detects incoming pulses, originating elsewhere on the energy delivery system, applied to the winding. A sensor detects output pulses after each input pulse has propagated through the winding. Data corresponding to the input and output pulses are stored. A processor computes the spectral densities of the data records. The logic then computes the characteristic signature, H(f), for the winding such that H(f) equals the average of Gxy divided by the average of Gxx for the valid data. Coherence is used to determine a valid H(f). A comparison of the H(f)'s over elapsed time using an error function indicates winding deformation or displacement.

Abstract: The winding testing unit provides a system and method for determining a characteristic signature of a winding residing in a device, such as a transformer or generator. A pulse/signal generator applies a suitable number of non-precise and non-identical pulses to the winding. A sensor detects output pulses after each applied input pulse has propagated through the winding. Data corresponding to the applied input and the detected output pulses are stored as data pairs in a memory. The processor executes logic to compute the auto-spectral density (Gxx) and the cross-spectral density (Gxy) for the data pairs. The logic then computes the characteristic signature, H(f), for the winding such that H(f) equals the average of Gxy divided by the average of Gxx for the data pairs. Comparison of the characteristic signatures over a period of time indicates winding deformation or displacement during the time period.

Abstract: The on-line winding test unit determines a characteristic signature of a monitored winding(s) in a transformer, generator, or the like. A sensor detects incoming pulses, originating elsewhere on the energy delivery system, applied to the winding. A sensor detects output pulses after each input pulse has propagated through the winding. Data corresponding to the input and output pulses are stored. A processor computes the spectral densities of the data records. The logic then computes the characteristic signature, H(f), for the winding such that H(f) equals the average of Gxy divided by the average of Gxx for the valid data. Coherence is used to determine a valid H(f). A comparison of the H(f)'s over elapsed time using an error function indicates winding deformation or displacement.

Abstract: The winding testing unit provides a system and method for determining a characteristic signature of a winding residing in a device, such as a transformer or generator. A pulse/signal generator applies a suitable number of non-precise and non-identical pulses to the winding. A sensor detects output pulses after each applied input pulse has propagated through the winding. Data corresponding to the applied input and the detected output pulses are stored as data pairs in a memory. The processor executes logic to compute the auto-spectral density (Gxx) and the cross-spectral density (Gxy) for the data pairs. The logic then computes the characteristic signature, H(f), for the winding such that H(f) equals the average of Gxy divided by the average of Gxx for the data pairs. Comparison of the characteristic signatures over a period of time indicates winding deformation or displacement during the time period.