A monitoring system includes an array of optical sensors disposed within a transformer tank. Each optical sensor is configured to have an optical output that changes in response to a temperature within the transformer tank. An analyzer is coupled to the array of optical sensors. The analyzer is configured to determine a sensed temperature distribution based on the sensed temperature. The sensed temperature distribution is compared to an expected distribution. Exterior contamination of the transformer tank is detected based on the comparison.

A monitoring system includes an array of optical sensors disposed within a transformer tank. Each optical sensor is configured to have an optical output that changes in response to a temperature within the transformer tank. An analyzer is coupled to the array of optical sensors. The analyzer is configured to determine a sensed temperature distribution based on the sensed temperature. The sensed temperature distribution is compared to an expected distribution. Exterior contamination of the transformer tank is detected based on the comparison.

A method for measuring a dissipation factor of a voltage divider of a capacitor voltage transformer (CVT). The CVT includes a capacitor voltage divider (CVD), an intermediate voltage transformer (IVT), and a compensating reactor (CR). The CR is connected between the CVD and the IVT. The method includes measuring a grounded specimen test (GST) mode current that passes through a first capacitor of the CVD by coupling the current sensor in series with the first capacitor, measuring an ungrounded specimen test (UST) mode current that passes through a second capacitor of the CVD by coupling the current sensor in series with the second capacitor, and obtaining a dissipation factor of the CVD based on the GST mode current and the UST mode current.

A method for measuring a dissipation factor of a voltage divider of a capacitor voltage transformer (CVT). The CVT includes a capacitor voltage divider (CVD), an intermediate voltage transformer (IVT), and a compensating reactor (CR). The CR is connected between the CVD and the IVT. The method includes measuring a grounded specimen test (GST) mode current that passes through a first capacitor of the CVD by coupling the current sensor in series with the first capacitor, measuring an ungrounded specimen test (UST) mode current that passes through a second capacitor of the CVD by coupling the current sensor in series with the second capacitor, and obtaining a dissipation factor of the CVD based on the GST mode current and the UST mode current.

A current-measuring transducer device has a current transducer for measuring an electric current along a conduction path. The current transducer has a magnetic field-sensitive element for converting the magnetic field resulting from the current flow along the conduction path into at least one physical variable and a measuring device for measuring the physical variable. The current transducer device has a coil arrangement with at least one coil for simulating the magnetic field resulting from the current flow along the conduction path. There is also described a method for calibrating a corresponding current transducer and a computer program product for performing the calibration method.

A system and method for phase and gain calibration of a current sensor system. The system comprises a microcontroller configured to execute software in an energy measurement component and a calibration computer having a calibration application. The energy measurement component receives first and second digital signals representing current and voltage signals, respectively, received from a test source, and calculates active power and a power factor, and provides those values to the calibration computer. The power factor is converted to a converted phase angle. Based on the information received from the energy measurement component, the calibration application calculates parameters used to update components within the microcontroller to maximize the accuracy of the current sensor system.

A system and method for phase and gain calibration of a current sensor system. The system comprises a microcontroller configured to execute software in an energy measurement component and a calibration computer having a calibration application. The energy measurement component receives first and second digital signals representing current and voltage signals, respectively, received from a test source, and calculates active power and a power factor, and provides those values to the calibration computer. The power factor is converted to a converted phase angle. Based on the information received from the energy measurement component, the calibration application calculates parameters used to update components within the microcontroller to maximize the accuracy of the current sensor system.

Embodiments of the present disclosure include methods, apparatuses, systems, and computer program product for enabling multi-point shunt calibration of a sensor device. Multi-point shunt calibration provides at least a first, second, and third simulated calibration output, each simulated calibration output corresponding to an actual reading value and an expected reading value. The simulated calibration outputs are associated with a predefined output sequence, where each simulated calibration output is separated from an adjacent simulated calibration output by an output step size. Some embodiments are configured for automatically outputting each simulated calibration output for a particular period of time before outputting an adjacent simulated calibration output in the predefined output sequence. The various simulated calibration outputs, actual reading values, and/or expected values may be used in determining calibrated reading values for the sensor device.

Embodiments of the present disclosure include methods, apparatuses, systems, and computer program product for enabling multi-point shunt calibration of a sensor device. Multi-point shunt calibration provides at least a first, second, and third simulated calibration output, each simulated calibration output corresponding to an actual reading value and an expected reading value. The simulated calibration outputs are associated with a predefined output sequence, where each simulated calibration output is separated from an adjacent simulated calibration output by an output step size. Some embodiments are configured for automatically outputting each simulated calibration output for a particular period of time before outputting an adjacent simulated calibration output in the predefined output sequence. The various simulated calibration outputs, actual reading values, and/or expected values may be used in determining calibrated reading values for the sensor device.

A test system is provided. The system includes a first test apparatus and a second test apparatus. A device power supply of the first test apparatus (ATE) is electrically connected with a device under test (DUT) through a driving branch (F) and a detecting branch (S), the driving branch (F) being configured to provide an original driving current to the DUT b the device power supply during testing, and the detecting branch (S) being configured to detect an effective driving current reaching the DUT. The second test apparatus includes a first voltage drop branch, the first voltage drop branch is connected to the detecting branch (S), and a voltage drop detected by the driving branch (F) is used to determine an effectiveness of an electrical connection formed between the driving branch and the device under test, and an electrical connection formed between the detecting branch (S) and the DUT.