Voltage divider assembly (1) for installation on a power conductor (100) inside a MV/HV switchgear in a power network of a national grid, operable to divide a voltage of the power conductor in a voltage-dividing sensor for sensing a voltage of the power conductor. The voltage divider assembly comprises a) conductive connecting means (180) for mechanically and electrically connecting the voltage divider assembly to the power conductor (100); and b) discrete impedance elements, electrically connected with the connecting means and in series with each other such as to be operable as a high-voltage side of the voltage-dividing sensor.

A capacitive voltage sensor for estimating voltage on a power line. The sensor includes a dielectric bushing surrounding the line, and an annular conductor formed in the bushing and being capacitively coupled to the line, where a first capacitance is defined between the line and the annular conductor and a second capacitance is defined between the annular conductor and ground. The sensor also includes a capacitance compensation circuit having an amplifier including a first terminal electrical coupled to the annular conductor, and first and second capacitance compensation capacitors electrically coupled to the terminals of the amplifier, where the compensation capacitors are made of different materials having different dielectric constants, and where the materials of the compensation capacitors are selected so as to compensate for changes in the first and second capacitances in response to temperature changes. Also, a thermistor is provided in a resistor compensation circuit to provide resistance compensation.

A capacitive voltage sensor for estimating voltage on a power line. The sensor includes a dielectric bushing surrounding the line, and an annular conductor formed in the bushing and being capacitively coupled to the line, where a first capacitance is defined between the line and the annular conductor and a second capacitance is defined between the annular conductor and ground. The sensor also includes a capacitance compensation circuit having an amplifier including a first terminal electrical coupled to the annular conductor, and first and second capacitance compensation capacitors electrically coupled to the terminals of the amplifier, where the compensation capacitors are made of different materials having different dielectric constants, and where the materials of the compensation capacitors are selected so as to compensate for changes in the first and second capacitances in response to temperature changes. Also, a thermistor is provided in a resistor compensation circuit to provide resistance compensation.

Improved power line management is provided by the systems and methods disclosed herein that accurately measures voltage in a power distribution system. In various embodiments, the system may include one or more sensor units, each coupled to the power lines using a capacitive or resistive voltage divider to yield a voltage at a sensor unit that is within a measurable range. In one aspect, this voltage may also be used to power the sensor unit and/or other devices coupled to it.

Improved power line management is provided by the systems and methods disclosed herein that accurately measures voltage in a power distribution system. In various embodiments, the system may include one or more sensor units, each coupled to the power lines using a capacitive or resistive voltage divider to yield a voltage at a sensor unit that is within a measurable range. In one aspect, this voltage may also be used to power the sensor unit and/or other devices coupled to it.

A high voltage capacitor for a voltage divider is described that is configured to sense an elevated voltage for medium and high voltage electrical distribution networks. The high voltage capacitor comprises a high voltage electrode, a measurement electrode, and an dielectric material disposed between the high voltage and measurement electrodes, wherein the dielectric material consists essentially of lanthanum oxide-zirconium oxide-titanium oxide (LZT) glass filler disposed in an insulating polymer matrix such that the capacitance of the dielectric material does not vary by more than +/−0.5% in the temperature range of −20° C. to 60° C.

A high voltage capacitor for a voltage divider is described that is configured to sense an elevated voltage for medium and high voltage electrical distribution networks. The high voltage capacitor comprises a high voltage electrode, a measurement electrode, and an dielectric material disposed between the high voltage and measurement electrodes, wherein the dielectric material consists essentially of lanthanum oxide-zirconium oxide-titanium oxide (LZT) glass filler disposed in an insulating polymer matrix such that the capacitance of the dielectric material does not vary by more than +/−0.5% in the temperature range of −20° C. to 60° C.

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.

Techniques, systems and articles are described for monitoring electrical equipment of a power grid and predicting likelihood failure events of such electrical equipment. In one example, a sensing device is configured to couple to an electrical power cable. The sensing device includes a plurality of concentric layers and a monitoring device. The plurality of concentric layers include a first layer, second layer, and third layer. The first layer is configured to concentrically surround a central conductor of the electrical cable and includes an insulating material. The second layer includes a conducting material. The third layer includes a resistive material configured to resist electrical flow between the second layer and a ground conductor exterior to the third layer. The monitoring device includes a sensor and communication unit configured to output data indicative of the sensor data.

A sensor device determines an alternating voltage between a conductor and a reference potential, particularly of a switch point drive. In order to reduce the installation cost and effort required to verify the absence of reaction, the sensor device has a sensor element, which is configured for capacitive coupling to the conductor, and a resistance element, which is provided for connection to the reference potential and is connected in series together with the sensor element. The sensor device further has a processing device, which is configured to determine a voltage drop via the resistance element.