Devices, systems, and methods for measurement of parameters of electric power transmission lines can improve electric power usage, while wireless circuitry can provide communication from field-located devices. Connection to draw electrical power from the transmission line can be distinct from connection to sense line parameters.

A clamp-type AC voltage probe includes: a clamp portion that clamps a cable to be measured; an electrode disposed to be opposed to the cable clamped by the clamp portion; a parallel circuit in which a capacitor and a resistance are connected in parallel, and one end of which is connected to the electrode; a resistance one end of which is connected to the other end of the parallel circuit and the other end of which is connected to a circuit ground; a capacitor one end of which is connected to the other end of the parallel circuit and the other end of which is connected to the circuit ground; and an amplifier an input terminal of which is connected to the one end or the other end of the parallel circuit, and that amplifies and outputs a signal input into the input terminal.

A clamp-type AC voltage probe includes: a clamp portion that clamps a cable to be measured; an electrode disposed to be opposed to the cable clamped by the clamp portion; a parallel circuit in which a capacitor and a resistance are connected in parallel, and one end of which is connected to the electrode; a resistance one end of which is connected to the other end of the parallel circuit and the other end of which is connected to a circuit ground; a capacitor one end of which is connected to the other end of the parallel circuit and the other end of which is connected to the circuit ground; and an amplifier an input terminal of which is connected to the one end or the other end of the parallel circuit, and that amplifies and outputs a signal input into the input terminal.

A switching device for controlling power flow on a power line. The device includes a current sensor for measuring primary current on the line, a first voltage sensor for measuring primary voltage on the line at one side of the switching device, and a second voltage sensor for measuring primary voltage on the line at another side of the switching device. An ADC converts measurement signals from the current sensor and the voltage sensors to digital signals, and a PMU calculates magnitude and phase angle synchrophasor data using the current and voltage measurement digital signals and calibration data.

A switching device for controlling power flow on a power line. The device includes a current sensor for measuring primary current on the line, a first voltage sensor for measuring primary voltage on the line at one side of the switching device, and a second voltage sensor for measuring primary voltage on the line at another side of the switching device. An ADC converts measurement signals from the current sensor and the voltage sensors to digital signals, and a PMU calculates magnitude and phase angle synchrophasor data using the current and voltage measurement digital signals and calibration data.

A power harvesting device is provided that may supply low voltage power to operate devices in remote locations. The power harvesting device may be connected to a medium to high voltage power line. First and second capacitors divide the voltage to a lower voltage sufficient to power a device, such as a monitoring device. The power harvesting device and monitoring device may be connected to an electric tower with the power harvesting device being connected to a power line supported by the tower.

A power harvesting device is provided that may supply low voltage power to operate devices in remote locations. The power harvesting device may be connected to a medium to high voltage power line. First and second capacitors divide the voltage to a lower voltage sufficient to power a device, such as a monitoring device. The power harvesting device and monitoring device may be connected to an electric tower with the power harvesting device being connected to a power line supported by the tower.

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 module type sensor includes a casing including a casing upper surface, a first casing side surface which is bent downward from the casing upper surface and has a lower end upwardly separated from a path through which a transmission line passes, and a second casing side surface which is bent downward from the casing upper surface and has a fixing bracket extending by being outwardly bent; a body unit fixedly installed inside the casing, formed of an insulator, supported by the printed circuit board at a lower end, and having, at a center, an opening which is open toward the transmission line; and a sensing substrate unit fixedly installed on an upper portion of the body unit, and including a voltage sensing circuit which is capacitively coupled to the transmission line exposed through the opening and a current sensing circuit which is inductively coupled to the transmission line.

A sensored insulation plug for a separable connector in a MV/HV power distribution network of a national grid, operable to sense the MV/HV elevated voltage. The sensored insulation plug includes a plug body formed by a solidified insulating material, a contact piece, and a discrete coupling capacitor embedded in the insulating material and operable to harvest energy from the elevated voltage of the contact piece and optionally operable to superimpose a communication voltage signal over the elevated voltage. The sensored insulation plug further includes an integrated sensing capacitor, operable as a high-voltage capacitor in a sensing voltage divider for sensing the elevated voltage. The sensing capacitor comprises a high-voltage electrode comprising the coupling electrode and the contact piece, a tubular sensing electrode, and a dielectric comprising a portion of the insulating material.