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

Abstract

A high-resolution sensor using a piezoelectric drum transducer is proposed for power frequency current sensing (50 Hz or 60 Hz). The utilization of the magnetic circuit helps to enhance the response to the electric currents in the power cords. The high sensitivity of the sensor originates from the superposition of the Ampere forces and the amplified piezoelectric effect of the drum transducer. The feasibility of the sensor was verified by experiments. The device exhibits a broad 3 dB bandwidth of 67.4 Hz without an additional magnetic field bias. The average sensitivity is 31.34 mV/A with a high linearity of 0.49%, and the resolution of the sensor attains 0.02 A. The resolution is much higher than that of the previous piezoelectric heterostructure for two-wire power-cords. Error analysis shows that the uncertainty reaches 0.01865 mV at the current of 2.5 A. Meanwhile, the device can generate a load power of 447.9 nW with an optimal load resistance of 55 KΩ at 10A (f = 50Hz) in energy harvesting experiments. The features of high sensitivity, excellent linearity, high resolution, low costs, and convenient installation demonstrate the application prospect of the proposed device for measuring power frequency currents in electric power grids.

Large bandwidth and dynamic range current sensor based on micro-PCB Rogowski coil

“…Resolution is the smallest change in current that the sensor can feel over the measuring range [17]. If the current varies slowly from a non-zero value, the output of the sensor does not change when the change does not exceed a certain value, that is, the sensor cannot distinguish the change in this input.…”

Editorial for the Special Issue on Piezoelectric Transducers: Materials, Devices and Applications, Volume II

“…This is the second volume of the Special Issue focused on piezoelectric transducers, covering a wide range of topics, including the design, fabrication, characterization, packaging, and system integration or final applications of mili/micro/nano-electro-mechanical systems-based transducers, featuring piezoelectric materials and devices. This new volume has compiled a total of 14 papers, with the latest advances in areas such as hysteresis compensation [1][2][3], cylindrical piezoelectric transducers [4], flextensional devices for underwater applications [5], electromechanical transformers [6], actuators for image stabilization [7], electric current sensing [8], rotary and linear ultrasonic motors [9,10], locomotion of miniature robots [11], displacement amplification structures [12] nanoparticles with piezoelectric properties [13], and a review paper on aerospace applications [14].…”