Abstract:
A clamp-on type electricity meter configured to measure current and/or voltage is disclosed, The electricity meter comprises at least one core assembly and a coil coiled around a structure of the corresponding core assembly, The coil is electrically connected to a printed circuit board (PCB), The core assembly is a split core comprising a first portion and a second portion attached to each other in a joint portion and the coil is an integrated part of the PCB.
Abstract:
The invention relates to a sensor (1) for measuring current in a conductor (19), the sensor (1) comprising a stack comprising at least one isolation layer (3) and at least two metallization layers (101, 102) stacked in a first direction (z), the sensor (1) comprising a first winding of conductive material and a second winding of conductive material, the first winding and the second winding each comprising a first part (5, 205, 305) formed in a metallization layer (101, 102) comprised in the stack and mainly extending in a second direction (y) and having a first centre of gravity (105, 210, 310) and a second part (7, 207, 307) formed in a metallization layer (101, 102) comprised in the stack and mainly extending in a direction opposite to the second direction (y) and having a second centre of gravity (106, 211, 311), the first centre of gravity (105) of the first winding and the second centre of gravity (106) of the first winding being comprised in a first plane, the second centre of gravity (210, 310) of the second winding and the second centre of gravity (211, 311 ) of the second winding being comprised in a second plane, wherein the first plane intersects with the second plane in a common intersection line in the second direction (y), wherein the first direction (z) and the second direction (y) are orthogonal directions and the sensor (1) further comprises measurement means (11) arranged to measure current through the first winding and current through the second winding.
Abstract:
An electricity meter for metering an amount of energy in accordance with a primary AC current and an AC supply voltage. The electricity meter comprises a current transformer comprising the primary conductor, a secondary winding, an auxiliary winding, and a magnetic core arranged to be magnetically coupled with the three windings. The electricity meter further comprises a circuit configured to provide the auxiliary winding with a test signal modulated in accordance with at least one of a first and a second modulation state. The test signal has the same frequency as the AC supply voltage. The electricity meter further comprises an electrical energy consumption measurement unit, coupled to the secondary winding, and being configured to provide a first test value as a function of a secondary current flowing through the secondary winding when the test signal is in a first modulation state, to provide a second test value as a function of a secondary current flowing through the secondary winding when the test signal is in a second modulation state, and to determine, on the basis of the first and second test values, whether a measurement fault warning signal is to be generated.
Abstract:
Characteristics of a line current of a power line in an electrical power system are measured using a current sensor having a core comprising an annular body receiving the power line therethrough and a secondary winding extending about a portion of the annular body in which the core has a high magnetic permeability and a low saturation level relative to the line current. While monitoring voltage induced in the secondary winding, a repeating peak magnitude of the induced voltage resulting from a reversal of magnetic flux in the core is identified and related to a primary alternating current in the power line. The ac current to be measured is thus not converted into another ac current, but instead the rate of change of flux is measured when the flux wave is crossing the zero.
Abstract:
Zum Feststellen von Wechselströmen höherer Frequenz in einem Gleichstromkreis (1) mit einer zwei Teilwicklungen (8, 9) aufweisenden strom kompensierten Drossel (10) werden Spannungen, die über den beiden Teilwicklungen (8, 9) abfallen, abgegriffen. Die abgegriffenen Spannungen werden derart überlagert, dass sich Anteile der Spannungen aufgrund von Gegentaktsignalen, die aufgrund eines Wechselstroms über den beiden Teilwicklungen (8, 9) abfallen, konstruktiv zu einer überlagerten Wechselspannung (16) aufaddieren, wobei sich Anteile der Spannungen, die aufgrund von Gleichtaktsignalen auftreten, destruktiv überlagern. Die überlagerte Wechselspannung (16) wird erfasst.
Abstract:
Verfahren und Einrichtung zur Messung elektrischer Differenzströme, die neben dem Wechsel auch einen Gleichstromanteil enthalten, mit Hilfe eines induktiven Differenzstromwandlers. Die bekannten Verfahren zur Messung gemischter Differenzströme erfordern spezielle Stromwandlerkonstruktionen in Bezug auf Spulenwicklung und Magnetkernmaterial und Kernanzahl. Das neue Verfahren kommt mit denselben Stromwandlern aus, die zur Messung reiner Differenzwechselströme üblich sind. Erfindungsgemäß wird dazu die Sekundärspule (3) des Stromwandlers derart angesteuert, dass der mit der Sekundärspule (3) verkettete Magnetfluss (Φ) im Kern unabhängig vom Differenzstrom konstant bleibt und der dafür nötige Sekundärstrom (Is) gemessen. Dazu wird einerseits der ohmsche Widerstand (Rcu) der Sekundärspule (3) im Sekundärstromkreis (4) durch einen elektronisch gebildeten, negativen Widerstand (Rz) kompensiert und andererseits ein definierter Magnetfluss zyklisch wiederhergestellt, indem der Sättigungsfluss (Φs) des Kerns als Referenzpunkt genutzt wird.
Abstract:
There is provided a voltage or current sensing device. An exemplary voltage or current sensing device includes a drive circuitry configured to deliver a drive current to a magnetic core operably coupled with a conductor, for driving the core to cyclical magnetic saturation. The device also includes sense circuitry configured to receive a voltage signal corresponding to an application current in the conductor. The device also includes signal processing circuitry configured to sample the voltage signal, wherein a first sample is in phase with the drive current and a second sample is out of phase with the drive current. The device also includes a feedback loop configured to deliver a compensation current to the magnetic core, wherein the compensation current is configured to balance the magnetic core and wherein the compensation current is based at least in part on the first sample in phase with the drive current.