A High-Precision Temperature Compensation Method for TMR Weak Current Sensors Based on FPGA

Area of Science:

• Electrical Engineering
• Materials Science
• Sensor Technology

Background:

• Tunnel Magnetoresistance (TMR) sensors offer high sensitivity for detecting weak currents, crucial for smart grids.
• Temperature fluctuations significantly degrade the accuracy of TMR sensors, limiting their real-world application.
• Existing compensation methods may not fully address the temperature-dependent errors in TMR sensors.

Purpose of the Study:

• To investigate the impact of temperature variations on the measurement accuracy of TMR sensors.
• To propose and validate a high-precision, software-based temperature compensation method for TMR sensors.
• To enhance the reliability of TMR sensors for weak current detection in smart grids under diverse thermal conditions.

Main Methods:

• Analysis of TMR sensor operating principles and temperature characteristics.
• Development of a compensation algorithm combining cubic spline interpolation, polynomial regression, and zero-point self-calibration.
• Implementation of a Field-Programmable Gate Array (FPGA)-based compensation circuit and experimental evaluation.

Main Results:

• The proposed compensation method significantly improves TMR sensor temperature stability.
• A marked reduction in the sensitivity temperature drift coefficient and improved zero-point drift stability were observed.
• The compensated TMR sensor demonstrated superior performance compared to other compensation techniques.

Conclusions:

• The developed software-based temperature compensation method effectively mitigates temperature-induced errors in TMR sensors.
• The enhanced TMR sensors exhibit improved accuracy and stability in complex temperature environments.
• This advancement enables more reliable weak current detection in smart grid applications across various conditions.