Method for sensing current in a conductor

Abstract

A sensor (11) comprises an inductor (18) for sensing an alternating current signal component of an observed signal. The inductor (18) comprises a substrate, conductive traces associated with different layers of the substrate, and one or more conductive vias for interconnecting the plurality of conductive traces. A magnetic field sensor (20) senses a direct current signal component of the observed signal. A first filtering circuit (26) has a high-pass filter response. The first filtering circuit (26) is coupled to the inductor (18) to provide a filtered alternating current signal component. A second filtering circuit (28) has a low-pass filter response. The second filtering circuit (28) coupled to the magnetic field sensor (20) to provide a filtered direct current signal component. A sensor fusion circuit (30) determines an aggregate sensed current based on the filtered alternating current signal component and the filtered direct current signal component.

Description

technical field [0001] The present disclosure relates to a method and sensor for sensing current in a conductor. Background technique [0002] Vehicles, equipment or machinery may use electric motors controlled by inverters or motor controllers. Prior art sensors can measure the current in one or more input conductors, such as wires or cables, that feed the electric motor from the inverter. More generally, prior art sensors can measure current flow in one or more conductors associated with any power electronics device using a power semiconductor, such as an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field Effect Transistor (MOSFET). [0003] Because some prior art sensors used to sense current in conductors associated with electric motors have poor resistance to thermal stress, the prior art sensors may fail prematurely. In some prior art sensors, self-heating of the ferromagnetic core from induced eddy currents and hysteresis losses can contr...

AI Technical Summary

Problems solved by technology

Other prior art sensors for sensing current in conductors can occupy a larger volume than desired because the maximum circuit density can be limited while efficiently handling thermal stress

But other prior art sensors may not respond adequately to rapid changes in current; thus, failing to respond to a sudden short circuit at the output of the inverter

Thus, there is a need for small sensors for sensing current that are resistant to reduced lifetime or failure associated with thermal stress or with inaccurate sensing of rapidly changing currents

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