A High-Resolution Electric Current Sensor Employing a Piezoelectric Drum Transducer

Area of Science:

• Electrical Engineering
• Materials Science
• Sensor Technology

Background:

• Accurate current sensing is crucial for power grid monitoring and management.
• Existing sensors may lack the required sensitivity, resolution, or linearity for specific applications.
• Piezoelectric materials offer potential for sensitive electromechanical energy conversion.

Purpose of the Study:

• To propose and validate a high-resolution sensor for power frequency current sensing (50/60 Hz).
• To investigate the sensor's performance characteristics, including sensitivity, linearity, bandwidth, and resolution.
• To explore the potential for energy harvesting using the developed sensor.

Main Methods:

• Development of a sensor utilizing a piezoelectric drum transducer and a magnetic circuit.
• Experimental verification of the sensor's feasibility and performance.
• Analysis of sensitivity, linearity, bandwidth, resolution, and uncertainty.
• Evaluation of energy harvesting capabilities at different current levels.

Main Results:

• The sensor achieved a broad 3 dB bandwidth of 67.4 Hz.
• Average sensitivity was 31.34 mV/A with excellent linearity (0.49%).
• High resolution of 0.02 A was attained, surpassing previous piezoelectric devices.
• Demonstrated energy harvesting capability of 447.9 nW at 10A.

Conclusions:

• The proposed piezoelectric drum sensor offers a promising solution for high-resolution power frequency current measurement.
• Its high sensitivity, linearity, and resolution, coupled with low cost and ease of installation, make it suitable for power grid applications.
• The sensor's energy harvesting capability adds further value for self-powered monitoring systems.