AC/DC Fields Demodulation Methods of Resonant Electric Field Microsensor

J. Micromech. Microeng.

Chu

et al. 2021

Self Cite

Based on the resonant electric field microsensors with coplanar electrodes, a novel non-intrusive measurement scheme of DC power-line voltage suitable for actual product is presented in this paper. Compared with using microsensors directly without some protection, employing the proposed scheme can avoid the influence of humidity and electromagnetic disturbance on non-contact voltage measurement. A theoretical model is developed to analyze the influence of the structural parameters of the proposed measurement scheme on its sensitivity and to predict the voltage response. Furthermore, the theoretical analysis reveals that the proposed scheme obtains the DC power-line voltage non-intrusively by measuring the voltage of a floating electrode. A prototype of the non-intrusive measurement apparatus of DC power-line voltage has been developed, calibrated, and tested. The prototype shows a favorable linear response characteristic with a linearity of 0.86%. And the experimental results are in good agreement with the theoretical results. The maximum relative deviation noticed is −2.16% over a range of voltages from −1000 V to 1000 V.

Section: Sensitivity S Efm−d Of the Efmmentioning

confidence: 99%

Non-intrusive DC voltage measurement based on resonant electric field microsensors

J. Micromech. Microeng.

Chu

et al. 2021

Self Cite

“…The study on the resonant electric field microsensor began in the 1990s, to our knowledge. Since then, the electric field resolution is being improved, from 630 V/m to 20.4 V/m, by various innovative micro sense structures [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ], under the parallel plate calibration. The electric field microchips were mostly exposed to the external environment for test, historically.…”

Section: Introductionmentioning

confidence: 99%

Resolution-Enhancing Structure for the Electric Field Microsensor Chip

Zhang

et al. 2021

Micromachines

Self Cite

Electrostatic voltage is a vital parameter in industrial production lines, for reducing electrostatic discharge harms and improving yields. Due to such drawbacks as package shielding and low resolution, previously reported electric field microsensors are still not applicable for industrial static monitoring uses. In this paper, we introduce a newly designed microsensor package structure, which enhances the field strength inside the package cavity remarkably. This magnification effect was studied and optimized by both theoretical calculation and ANSYS simulation. By means of the digital synthesizer and digital coherent demodulation method, the compact signal processing circuit for the packaged microsensor was also developed. The meter prototype was calibrated above a charged metal plate, and the electric field resolution was 5 V/m, while the measuring error was less than 3 V, from −1 kV to 1 kV in a 2 cm distance. The meter was also installed into a production line and showed good consistency with, and better resolution than, a traditional vibratory capacitance sensor.

A non-intrusive voltage measurement scheme based on MEMS electric field sensors: Theoretical analysis and experimental verification of AC power lines

Review of Scientific Instruments

et al. 2021

A non-interference AC voltage measurement system based on a resonant electric field microsensor is proposed. The equivalent circuit of the proposed system is established, which shows that the frequency response function is only related to the capacitances of the system structure in the kHz low-frequency range. Furthermore, the sensitivity analysis and experiments demonstrate that the amplitude sensitivity is independent of the frequency of an unknown AC voltage. Therefore, this technique is very suitable for measuring arbitrary waveform voltage. A functional prototype was developed and tested to acquire AC power-line voltages. The prototype responded well to the transient waveform of the AC input signal, yet with a phase delay of 177.24°. The output of the system was linear in the range of 0–1000 Vrms at 50-Hz and the linearity was 0.54%, whereas the maximum relative deviation of the rms voltage measurements above 10 V was −0.83%. Finally, the shielding ability of the system against interference and noise was verified through the AC interference voltage measurement.