Electrical current transducer to measure the current flowing in a primary conductor, the transducer including an outer casing, a magnetic core comprising a magnetic circuit gap, a magnetic field detector comprising a sensing portion positioned in the magnetic circuit gap, an insulating core housing, a secondary coil formed from a wire wound around a coil support portion of the insulating core housing, and an electrostatic shield. The electrostatic shield is positioned between secondary coil and a radially inner wall portion of the outer casing, the radially inner wall portion defining a passage configured to receive said primary conductor therethrough. The electrostatic shield comprises a skirt portion formed by a plurality of flexible strips extending axially from an edge of the shield, the flexible strips configured to elastically bias against a base wall portion of the outer casing.

A current sampling system, the system including a magnetic component, that is an inductor or a transformer that has at least one winding, where the at least one winding has a first part and a second part, where a first terminal of the first part is connected to a first terminal of the second part, and where a second terminal of the first part is separated from a second terminal of the second part, and a current detection circuit, where the second terminal of the second part is connected to the current detection circuit, and where the current detection circuit is configured to sample a current flowing through the second part, and obtain a total current of the winding based on the sampled current flowing through the second part and a preset ratio.

An installation fixture for installing a device on a power line is disclosed. The fixture includes a lower cradle that may receive one part of the device, an upper cradle that may receive another part of the device, and a base. The installation fixture may be installed on a worker carrier for a boom truck or the like. The orientation of the lower cradle may be adjusted relative to the base to facilitate the installation on the power line. The upper cradle may be moved between an open position (where the parts may be loaded into the fixture) and a closed position (where the power line is captured between the two parts of the device) and at which time that parts can be secured together.

Electrical current transducer including a magnetic core comprising a magnetic circuit gap, a magnetic field detector comprising a sensing portion positioned in the magnetic circuit gap, an insulating support body comprising a coil support portion and a coil terminal connection portion, and a secondary coil formed from a wire wound around the coil support portion. The coil support portion has a generally U-shaped cross-sectional profile comprising a base wall, a radially inner wall extending from the base wall and a radially outer wall extending from the base wall, the radially inner and outer walls having a height configured such that open end edges thereof extend slightly beyond an axial thickness of the magnetic core including any manufacturing tolerances such that the open end edges are folded inwards around corners of the magnetic core by the coil wound around the magnetic core housing.

A current monitor for a transmission line having powered active components is provided. A current monitor includes: a housing configured to be coupled to a transmission line, an inductive current sensor in the housing configured to measure a value of the current on the transmission line to generate a sensor signal, a power source, and a sensor signal conversion circuit in the housing configured to receive power from the power source and to generate a current output signal based on the sensor signal, the current output signal having a natively useful form.

A signal is outputted via a transmission path with little attenuation while eliminating high-frequency noise. A current sensor includes: a coil wound around a magnetic core through whose interior a measured electrical path is inserted, is connected to ground at one end, and outputs a current with a current value in keeping with a current value of a measured current flowing on the measured electrical path; a constant impedance filter whose input terminal is connected to another end of the coil, limits a frequency range of the current inputted from the input terminal to a desired frequency range, and outputs the detection current from an output terminal; a transmission path that is directly connected at one end to the output terminal; and a terminating resistance that is connected between another end of the transmission path and ground and converts the current flowing via the transmission path to a detection voltage.

A current detector includes: a current detection unit including a plurality of cores made of magnetic material, in the plurality of penetration holes are penetrating through, respectively; a terminal block including a plurality of terminal connecting portions being arranged side by side in a direction perpendicular to an axial direction of the penetration holes, the terminal block being merged with the current detection unit; and a plurality of conductor bars, each having one end inserted into one of the penetration holes and another end connected to corresponding one of the terminal connecting portions.

A device and method for evaluating long-term operation of a transformer oil pump. An inlet of an oil pump is connected to an outlet of an oil tank through an oil pipe, and an outlet of the oil pump is connected to an inlet of the oil tank through an oil pipe. A pressure gauge is provided on the oil pipe to the inlet and the outlet of the oil pump, respectively. An ultra-high-frequency (UHF) sensor is provided on an inner wall of an oil pipe close to the oil pump. A pressure difference between the oil pipes to the inlet and to the outlet of the oil pump is monitored. A three-phase unbalanced current of a stator winding is monitored. The vibration of the oil pump is monitored. The rotor-to-stator rub is monitored. Based on the above inspection, a long-term health status of the oil pump is determined.

Accurate measurements of electrical power at various points of a power grid is becoming more important and, at the same time, is getting more difficult as the old power distribution model of a few, large power generating stations and a multitude of relatively linear loads is replaced by a newer model containing a multitude of smaller, and to some degree unpredictable power sources, as well as a multitude of not always linear and often smart (essentially also unpredictable) loads. Embodiments of the invention provide for management of AC current measurements in the presence of a DC current. Such current measurement management including at least alarms, feedback, and forward correction techniques exploiting magnetic field measurements from within the magnetic core or upon the surface of magnetic elements and/or shields within the current transducer.

This current detection device is configured from: an annular magnetic material core that forms a closed magnetic path around a pair of conducting wires in which conduction currents flow; an excitation coil wound on the magnetic material core; an oscillation circuit unit that applies a rectangular wave output voltage to the excitation coil; a power supply unit that supplies power to an operation amplifier that generates the rectangular wave output voltage in the oscillation circuit unit; and a difference current calculation unit, which detects a power supply current flowing from the power supply unit to the operation amplifier, and which calculates a difference current between the conduction currents flowing in the pair of conducting wires. Consequently, excellent noise resistance is achieved, and the configuration of the current detection device is simplified.