Multi-air-gap magnetoresistance current sensor for alternating current and direct current, and current measuring method

A multi-air-gap magnetoresistance current sensor for alternating current-direct current, comprising:

• a magnetoelectric conversion unit, configured to:
• obtain a magnetic field signal of a target current-carrying wire with a to-be-measured current;
• and convert the magnetic field signal into a voltage signal and output the voltage signal to a signal processing unit, wherein the magnetoelectric conversion unit comprises an iron core and N new magnetoresistance elements connected in parallel, N air-gap openings are symmetrically arranged on the iron core, and the N new magnetoresistance elements are respectively located at centers of the N air-gap openings, N≥3 and N is a positive integer;
• the signal processing unit, configured to:
• amplify the voltage signal output by the magnetoelectric conversion unit, and output the amplified voltage signal to a feedback compensation unit;
• and
• the feedback compensation unit, configured to:
• adjust a feedback current based on the amplified voltage signal output by the signal processing unit to enable the new N magnetoresistance elements to operate at zero magnetic flux;
• measure a value of the feedback current;
• and obtain a value of the to-be-measured current based on the value of the feedback current, and output the value of the to-be-measured current.