Non-Contact Voltage Measurement Using a Micro-Resonator

Abstract

A non-contact voltage sensor that realizes isolation from the main circuit of the power line is proposed. A high voltage generates an electrostatic force, and sensing is based on the nature of the electrostatic force. Applying the electrostatic force can be like adding a negative spring to a resonator in that the resonance frequency decreases with the voltage. A parallel plate electrode is used for sensing due to the strong gap dependency, and a comb electrode is used to excite the vibration of the resonator because it contributes very little to the gap dependence. The relationship between the shift of the resonance frequency and the applied voltage is well-explained by theory.