Research on a miniaturized wireless self-powered AC electric field sensor

With the transformation of smart grids toward informatization and intelligence, the long-term precise monitoring of electric fields a critical physical quantity reflecting grid operating states—is essential for equipment fault diagnosis and electromagnetic environment assessment. However, traditional electric field sensors face challenges such as large size, high power consumption, and reliance on battery replacement, making them unsuitable for distributed sensor network deployment. To address these issues, this study proposes a miniaturized self-powered AC electric field sensor integrating 2.4 GHz radio frequency (RF) energy harvesting and a differential dual-electrode structure, resolving the limitations of battery dependency and insufficient measurement accuracy in conventional sensors. The designed sensor measures only 22.8 mm × 19.0 mm, featuring a wide frequency response (10 Hz–100 kHz), high linearity at 50 Hz (R² > 0.99998), a minimum resolution of 165 V/m/Hz¹/², and low power consumption, meeting high-precision measurement requirements for sinusoidal, triangular, and lightning electric fields. Experimental results demonstrate that the integrated system achieves a cyclic operation of 9 minutes of active operation (25–50mW power consumption) and 5 minutes of low-power sleep within a 14-minute period when placed 15 cm from an 800mW RF source. This sensor fulfills the miniaturization, low-power, and high-precision demands for distributed monitoring in smart grids, providing a sustainable solution for high-voltage equipment condition diagnosis and electromagnetic environment evaluation.