Electromagnetic actuator with multiple windings

Abstract

An electromagnetic actuator for protecting circuits, comprising a plurality of windings surrounding a movable magnetic core, the movable magnetic core being able to move from a rest position to an actuated position under the action of a magnetic field generated by the windings, and the movable magnetic core is The plurality of windings includes: - a differential winding (2), which generates a magnetic field in response to a differential type fault on the current line to be protected; - a magnetic winding (1), which is embedded with the differential winding (2) , and generates a magnetic field in response to a short-circuit type fault on the current line to be protected. The electromagnetic actuator is characterized in that it also includes a third winding (3), which is wound into a short circuit and embedded with the differential winding (2) and the magnetic winding (1). position to generate a magnetic field opposite to the magnetic field generated by the magnetic winding (1).

Description

technical field [0001] The present invention relates to an electromagnetic actuator having increased resistance to electrical shock. The invention relates in particular to electromagnetic actuators for use in connection with trigger locks for electrical equipment protecting lines, such as shut-off and / or differential equipment dependent on mains voltage. [0002] These devices should be triggered in very specific conditions, typically when an imbalance is created between the amount of current entering the line protected by the device in question and the amount of current coming out of that line, which corresponds to the differential "Differential" protection following a dynamic fault, or when the current strength is abnormally high, this corresponds to "magnetic" protection following a short-circuit fault. [0003] Actuators traditionally comprise windings around a movable magnetic core which is movable from a rest position to an actuated position under the action of a magnet...

AI Technical Summary

Problems solved by technology

This solution allows avoiding a breakdown in the case of a current wave of 8 / 20 μs, but has the disadvantage that during a voltage wave of 1.2 / 50 μs due to the very large current consumed by the two varistors in series (approx. 1000A), increasing the voltage at the terminals of the control element (about 1000V)

Therefore, it will consist of a 1200V thyristor or IGBT, a relatively expensive component

[0013] Adding a resistor upstream of the differential winding to limit the current through the varistor is feasible, but this brings back the compactness of the actuator into question and the control element in order to withstand both the 1.2 / 50µs voltage ripple and the 8 / 20µs The current wave will still choose from expensive components

[0014] Therefore the currently used solutions are relatively expensive

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