Related Experiment Video
Updated: Jul 24, 2025

A Simple Approach to Perform TEER Measurements Using a Self-Made Volt-Amperemeter with Programmable Output Frequency
Published on: October 5, 2019
Design and Optimization of Multi-Stage TMR Sensors for Power Equipment AC/DC Leakage Current Detection
Xiaoxu Hu1, Xuetao Duan1, Wei Zhang1
1State Key Laboratory of Power Transmission Equipment and System Security, Chongqing University, Chongqing 400044, China.
Abstract:
Tunnel magnetoresistance (TMR) can measure weak magnetic fields and has significant advantages for use in alternating current/direct current (AC/DC) leakage current sensors for power equipment; however, TMR current sensors are easily perturbed by external magnetic fields, and their measurement accuracy and measurement stability are limited in complex engineering application environments. To enhance the TMR sensor measurement performance, this paper proposes a new multi-stage TMR weak AC/DC sensor structure with high measurement sensitivity and anti-magnetic interference capability. The front-end magnetic measurement characteristics and interference immunity of the multi-stage TMR sensor are found to be closely related to the multi-stage ring size design via finite element simulation. The optimal size of the multipole magnetic ring is determined using an improved non-dominated ranking genetic algorithm (ACGWO-BP-NSGA-II) to derive the optimal sensor structure. Experimental results demonstrate that the newly designed multi-stage TMR current sensor has a measurement range of 60 mA, a fitting nonlinearity error of less than 1%, a measurement bandwidth of 0-80 kHz, a minimum AC measurement value of 85 μA and a minimum DC measurement value of 50 μA, as well as a strong external electromagnetic interference. The TMR sensor can effectively enhance measurement precision and stability in the presence of intense external electromagnetic interference.
More Related Videos
06:45Design and Application of a Fault Detection Method Based on Adaptive Filters and Rotational Speed Estimation for an Electro-Hydrostatic Actuator
Published on: October 28, 2022
05:11High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition
Published on: June 27, 2025
Related Concept Videos
Three-Phase Short Circuit—Unloaded Synchronous Machine
This behavior occurs due to the magnetic flux produced by the short-circuit armature currents. Initially, these currents follow high-reluctance paths but eventually shift to...
Power System Three-Phase Short Circuits
Differential Relays
Series R—L Circuit Transients
Using Kirchhoff's Voltage Law (KVL) to analyze this circuit helps determine the total asymmetrical fault current, which consists...
Overcurrent Relays
Instantaneous overcurrent relays activate immediately when the input current exceeds a predetermined value, known as the pickup current, instantly energizing the circuit breaker trip coil. This rapid response is vital for addressing severe faults quickly.
Time-delay overcurrent relays, on the other...
Energy Losses in Transformers
There are four main reasons for energy losses in transformers.
The first cause can be the high resistance of the...