Individual coils as well as two or more coils arranged one over the other or one coil in combination with a sensor, which can be integrated into planar semiconductor technology are described. A coil comprises a turn and two supply lines for supplying current to the coil. The turn and the supply lines are formed from a metal layer. One of the two supply lines is connected to a first end of the turn and the other of the two supply lines is connected to a second end of the turn.

The present disclosure is a system and method for measuring AC residual current and DC residual current using a singular type-B residual current monitoring device. The system includes a sensor comprising two or more cores that measure residual AC current and residual DC current from two or more current carrying conductors through the cores that carry AC current and DC current. The system includes a controller that sends both an AC excitation current to the cores, as well as a DC nulling current that cancels out the DC residual current, allowing the system to then accurately measure the AC residual current. The system also includes a self-test feature that injects known quantities of both AC current and DC current through the sensor to determine if the sensor is functioning properly.

The present disclosure is a system and method for measuring AC residual current and DC residual current using a singular type-B residual current monitoring device. The system includes a sensor comprising two or more cores that measure residual AC current and residual DC current from two or more current carrying conductors through the cores that carry AC current and DC current. The system includes a controller that sends both an AC excitation current to the cores, as well as a DC nulling current that cancels out the DC residual current, allowing the system to then accurately measure the AC residual current. The system also includes a self-test feature that injects known quantities of both AC current and DC current through the sensor to determine if the sensor is functioning properly.

The present disclosure relates to filters. Teachings thereof may be embodied in a filter assembly, e.g., a filter assembly for filtering output currents from a voltage converter. For example, a filter assembly may include: a current conductor with a curved profile; a first ferrite body; a second ferrite body; and a recess with a curved profile defined in at least one of the first ferrite body and the second ferrite body. The first ferrite body and the second ferrite body may combine to surround the current conductor and the current conductor may extend along the recess.

The present disclosure relates to filters. Teachings thereof may be embodied in a filter assembly, e.g., a filter assembly for filtering output currents from a voltage converter. For example, a filter assembly may include: a current conductor with a curved profile; a first ferrite body; a second ferrite body; and a recess with a curved profile defined in at least one of the first ferrite body and the second ferrite body. The first ferrite body and the second ferrite body may combine to surround the current conductor and the current conductor may extend along the recess.

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 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.

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.