Wide-range broadband current sensor base on tunnel magnetic resistance effect

Abstract

The invention provides a wide-range broadband current sensor base on a tunnel magnetic resistance effect, and belongs to the field of sensing measurement. The sensor comprises an open magnet ring, current sensing chips, a compensation coil, a sampling resistor, an instrument amplifier, a zeroing circuit, a current output module and a power supply module; the current sensing chips include a high-sensitivity TMR sensing chip and a low-sensitivity TMR sensing chip, and are provided with two current measuring output points; the open magnet ring sleeves a current carrying lead, so that the current carrying lead penetrates through an inner hole of the open magnet ring; the compensation coil is wound around the open magnet ring; the high-sensitivity TMR sensing chip is arranged in an open air gap position of the open magnet ring; the low-sensitivity TMR sensing chip is arranged outside the open magnet ring; the high-sensitivity TMR sensing chip with other composition parts forms a closed loop structure; and the low-sensitivity TMR sensing chip, the instrument amplifier and the zeroing circuit form an open loop structure. The current sensor has the advantages of being wide in measuring range, wide in frequency band, small in size, high in precision, low in cost, free of intrusion and convenient to install and maintain.

Description

Technical field [0001] The invention belongs to the technical field of sensing and measurement, and particularly relates to a wide-range and wide-band current sensor using two tunnel magnetoresistance (TMR) sensor chips with high sensitivity and low sensitivity, and the measurement range covers hundreds of microampere leakage current to several Thousand-ampere impulse current. Background technique [0002] The development of smart grids requires the support of various technologies. Among them, advanced sensing and measurement technologies are the basis for real-time monitoring and control of smart grids, which are of great significance to the realization of smart grids. In the current power system, the monitoring of the transmission and distribution system needs to be further improved. This is mainly due to the wide distribution of transmission lines in the transmission and distribution system, the huge number of electrical equipment, the wide range of voltage and current levels,...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem that current sensors cannot simultaneously measure leakage currents of hundreds of microamperes and impulse currents of kiloamperes, the present invention proposes a wide-range and wide-band current sensor based on the tunnel magnetoresistance effect

Images