Schweitzer Engineering Laboratories, Inc.

Travis C Mallett

Robert Lopez, Jr

Ben M Armstrong

Forrest A Rahrer

Edmund O Schweitzer, Iii

Bogdan Zdzislaw Kasztenny

Veselin Skendzic

The present disclosure pertains to systems and methods for monitoring a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. A first current transformer is disposed between the stack of capacitors and the first ground connection. The current transformer provides an electrical signal corresponding to a current associated with the CCVT. A second transformer is disposed to provide a second electrical signal related to the CCVT. The second signal may be a voltage signal or a current signal. An intelligent electronic device (IED) in electrical communication with the current measurement devices monitors a health factor comprising a ratio of magnitudes or a difference between phases from the transformers at a single frequency. The health factor is compared against an acceptable range and an alarm is generated when the range is exceeded.

Capacitance-coupled voltage transformer monitoring

The present disclosure relates to systems and methods using thermal vias to increase the current-carrying capacity of conductive traces on a multilayered printed circuit board (PCB). In various embodiments, parameters associated with vias may be selected to control various electrical and thermal properties of the conductive trace. Such parameters include the via diameter, a plating thickness, a number of vias, a placement of the vias, an amount of conductive material to be added or removed from the conductive trace, a change in the resistance of the conductive trace, a change in a fusing measurement of the conductive trace, and the like.

High-current PCB traces

The present disclosure pertains to systems and methods for monitoring a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. A first current transformer is disposed between the stack of capacitors and the first ground connection. The current transformer provides an electrical signal corresponding to a current associated with the CCVT. A second current transformer is disposed between a primary winding of a step-down transformer associated with the CCVT and a second ground connection. An intelligent electronic device (IED) in electrical communication with the current measurement devices monitors a ratio of magnitudes from the current transformers at a single frequency. The ratio is compared against an acceptable range. When the ratio exceeds the acceptable range, an alarm is generated.

The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. Electrical signals from accessible portions of the CCVT are used to detect traveling waves. Current and/or voltage signals may be used. In various embodiments, a single current may be used. The traveling waves may be used to detect a fault on the electric power delivery system.

High-fidelity voltage measurement using a capacitance-coupled voltage transformer

Disclosed are systems and methods for identifying and reporting failures of an analog-to-digital converter (ADC). Specifically, the systems and methods described herein evaluate quantization noise properties of ADCs, including delta-sigma ADCs and successive approximation register (SAR) ADCs, to verify functionality and/or identify failures. Quantization noise properties can be evaluated in the frequency domain by, for example, comparing RMS values, magnitudes, frequency spectrums, and the like, in various frequency bands to threshold values and/or to verify an expected noise shape. Quantization noise properties can additionally or alternatively be evaluated in the time domain by, for example, comparing counts of pulse widths, average pulse widths, and/or number of transitions within a sequence of pulses to threshold values and/or to similar identifiable characteristics in other pulse width bands.

Analog-to-digital converter verification using quantization noise properties

The present disclosure provides systems and methods for identifying failures in an analog to digital (A/D) converter. An intelligent electronic device (IED) may monitor a digital output of one or more A/D converters. The IED may determine a slope value limit associated with the A/D converter. The IED may determine an output slope value of the digital output based on a difference of a converter output value measured at a first time and a converter output value measured at a later time. If the determined output slope value exceeds the slope value limit, the IED may identify a failure of the A/D converter. An IED may determine that concurrent failures in multiple, parallel A/D converters are indicative of a problem upstream from the A/D converters.

Systems and methods for identifying a failure in an analog to digital converter

Systems and methods for identifying and reporting failures of an analog to digital (A/D) conversion system are presented. The systems and methods may detect and report a problem of input circuitry of an A/D converter and/or an A/D converter itself. For example, an identifiable characteristic can be introduced into the input signal provided to an A/D converter. The A/D converter may output a digital value that includes the identifiable characteristic of the A/D converter input. A monitoring system may determine and/or report a change in, or a failure of, the A/D converter or input circuitry thereto, based on the identification, non-existence of, or variation in the identifiable characteristic in the digital output.

Systems and methods for analog to digital converter failure identification

Disclosed are systems and methods for identifying and reporting failures of an analog to digital (A/D) conversion system. An A/D conversion system includes a test signal generator configured to generate a test signal including an identifiable characteristic, an A/D converter configured to convert an analog signal measured at an input of the A/D converter to a digital output, and signal injection circuitry configured to inject at least a portion of the test signal from the test signal generator as an injected signal into the analog signal using trace-to-trace crosstalk. A method includes determining whether the digital output generated by the A/D converter indicates the identifiable characteristic.

The present disclosure provides systems and methods for identifying and reporting failures of an analog to digital (A/D) conversion system. The systems and methods are configured to detect and report a failure of a preamplifier of the A/D conversion system and/or a failure of a A/D converter of the A/D conversion system. A high frequency component can be included in the input of an A/D converter. The A/D converter is configured to output a digital value to the A/D conversion system, wherein the digital value includes the high frequency component of the A/D converter input. The A/D conversion system is configured to determine an output status, including a frequency component and a corresponding amplitude, and to determine a failure of the A/D conversion system based on the determined output status. The A/D conversion system can report a change in, or a failure of, the A/D converter, and can operate or prevent operation of protection elements.

The present disclosure provides systems and methods for identifying changes in and failures of a reference voltage of an analog to digital (A/D) converter. A non-scalar function of the reference voltage of the A/D converter can be determined and output to the A/D converter. The A/D converter is configured to output a digital value to the A/D conversion system, wherein the digital value corresponds to the non-scalar function of the reference voltage. The A/D conversion system decodes the non-scalar function of the reference voltage with a corresponding inverse function, and may determine the drift factor associated with the reference voltage. The A/D conversion system can report a change in, or a failure of, the A/D converter or its reference voltage, and can operate or prevent operation of protection elements.

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Pullman, WA, United States of America

Travis C Mallett