The invention relates to a member (O1) for measuring a variable representative of a common mode voltage (Vres) in an electrical network (1) or in a device (E), the network (1) or the device (E) comprising at least a first power conductor (C1) and a second power conductor (C2), the measuring member (O1) comprising two capacitive elements (EC1, EC2) which are intended to be arranged in a bridge between the two power conductors (C1, C2) and have capacity values that are identical to each other, wherein the two capacitive elements (EC1, EC2) are connected at a midpoint (M). The measuring member (O1) also comprises a two-terminal measurement circuit (SH) connected on the one hand to the midpoint (M) and on the other hand to a connection terminal intended to be electrically connected to a common conductor (Cc) provided in the electrical network (1) or the device (E).

A partial discharge (PD) detection system includes a node including a sensor configured to capacitively couple to a shield layer of a cable of an electric power line. The sensor is configured to collect, from the cable, sensor data indicative of an alternating-current (AC) electrical signal in the cable. The system further includes a high-pass filter configured to filter out low-frequency signals from the sensor data, and processing circuitry configured to detect, based on the filtered sensor data, a PD event at a location on the cable that is local to the sensor.

A partial discharge (PD) detection system includes a node including a sensor configured to capacitively couple to a shield layer of a cable of an electric power line. The sensor is configured to collect, from the cable, sensor data indicative of an alternating-current (AC) electrical signal in the cable. The system further includes a high-pass filter configured to filter out low-frequency signals from the sensor data, and processing circuitry configured to detect, based on the filtered sensor data, a PD event at a location on the cable that is local to the sensor.

A voltage measurement device includes a probe module movably arranged around an alternating-current transmission line, and a measurement unit. A metal electrode is arranged on a surface of the probe module facing toward the alternating-current transmission line, electrically coupled with the alternating-current transmission line to form a coupling capacitor, and then forms an electrical circuit with an inductor element, a resistor element, and a reference signal source in the measurement unit. A processor controls the reference signal source to input reference voltage signals at different frequencies to the electrical circuit, determines a resonant frequency of the electrical circuit according to currents of the electrical circuit under the reference voltage signals at different frequencies, and determines a voltage of the alternating-current transmission line according to a first current component amplitude and the resonant frequency of the electrical circuit. A voltage measurement method and a storage medium are also disclosed.

A system and method for calibrating a capacitor voltage sensor that measures voltage on a power line coupled through a switch to a primary coil of a transformer. The method includes measuring a control voltage on a secondary coil of the transformer and measuring voltage on the capacitor sensor when the switch is known to be closed. The method identifies a calibration factor that when multiplied by the measured voltage on the capacitor sensor when the switch is closed makes the measured voltage on the capacitor sensor substantially equal to the control voltage. The method subsequently measures voltage on the capacitor sensor when the switch is open or closed during operation of the transformer, and multiplies the subsequently measured voltage on the capacitor sensor when the switch is open or closed by the calibration factor to obtain a measured voltage.

A system and method for calibrating a capacitor voltage sensor that measures voltage on a power line coupled through a switch to a primary coil of a transformer. The method includes measuring a control voltage on a secondary coil of the transformer and measuring voltage on the capacitor sensor when the switch is known to be closed. The method identifies a calibration factor that when multiplied by the measured voltage on the capacitor sensor when the switch is closed makes the measured voltage on the capacitor sensor substantially equal to the control voltage. The method subsequently measures voltage on the capacitor sensor when the switch is open or closed during operation of the transformer, and multiplies the subsequently measured voltage on the capacitor sensor when the switch is open or closed by the calibration factor to obtain a measured voltage.

A capacitive voltage sensor assembly includes a first electrode extending along a longitudinal axis, the first electrode including a first end and a second end opposite the first end, a second electrode surrounding the second end of the first electrode, the second electrode including a tubular portion having a first end and a second end opposite the first end, and a base portion coupled to the first end of the tubular portion, and a mass of dielectric insulating material at least partially encapsulating the first electrode and the second electrode. The tubular portion includes a plurality of cantilevered tabs interconnected at the first end of the second electrode. Each tab of the plurality of cantilevered tabs is circumferentially separated from an adjacent tab of the plurality of cantilevered tabs to define a gap therebetween at the second end of the second electrode.

A capacitive voltage sensor assembly includes a first electrode extending along a longitudinal axis, the first electrode including a first end and a second end opposite the first end, a second electrode surrounding the second end of the first electrode, the second electrode including a tubular portion having a first end and a second end opposite the first end, and a base portion coupled to the first end of the tubular portion, and a mass of dielectric insulating material at least partially encapsulating the first electrode and the second electrode. The tubular portion includes a plurality of cantilevered tabs interconnected at the first end of the second electrode. Each tab of the plurality of cantilevered tabs is circumferentially separated from an adjacent tab of the plurality of cantilevered tabs to define a gap therebetween at the second end of the second electrode.

A sensor for a separable connector includes a plug body, one or more high voltage capacitors, one or more low voltage capacitors, and a low voltage connection. The plug body includes an insulating resin. The plug body can be inserted into the separable connector to encase a high voltage conductor disposed in the separable connector. The one or more high voltage capacitors are encased by the insulating resin and can be electrically coupled to the separable connector at a first end portion when the plug body is inserted. The one or more low to voltage capacitors are electrically coupled in series to the one or more high voltage capacitors to form a capacitive voltage divider. The low voltage connection provides a low voltage signal corresponding to a high voltage signal present in the separable connector. Signal conditioning electronics or a memory may also be included.

A common-mode voltage measurement apparatus according to an embodiment includes a measurement electrode attached to a conductor capable of being brought into contact with a coated cable, a measurement circuit configured to measure a common-mode voltage generated in the cable, and a compensation circuit connected in series between the measurement electrode and the measurement circuit, the compensation circuit being configured to compensate for a parasitic capacitive component formed between the measurement electrode and the conductor.