A Piezoelectric–Piezoresistive Coupled Electric Field Sensor for Large Dynamic Range Measurement From DC to 1.5 kHz

The electric field intensity is a critical parameter in electrical power systems, providing significant insights into the system’s condition. Electric field sensors (E-sensors) are essential for monitoring variations in electric field strength. The current challenge facing E-sensors is to achieve the detection of dc electric fields while ensuring a wide dynamic range of field strengths. This article proposes a novel E-sensor that combines piezoelectric-piezoresistive (PE-PR) elements in its sensitive structure. This article proposes a novel E-sensor that combines PE-PR elements in its sensitive structure. Shielding plates are positioned on both the upper and lower sides of the PE-PR sensitive element. The conductive states of the two shield plates are controlled through a switching circuit, enabling the modulation and testing of dc electric fields. This design overcomes the incompatibility between dc electric field testing and a wide dynamic range of electric field strengths in E-sensors. This passive sensor can perform electric field measurements within a dc–1.5-kHz bandwidth from 0 to 150 kV/m, with a linearity of less than 0.92%, a field resolution up to 50 V/m, sensitivity reaching 1.06 mV/kV/m (@ 1500 Hz), 128 mV/kV/m (@ dc), and hysteresis error less than 2%. The specifications can be customized according to requirements. Compared to existing research, this E-sensor meets basic measurement requirements and offers the advantages of a simplified fabrication process and smaller dimensions. The relatively small sensor allows for integration into most power electrical equipment.