MEMS Microphone for Acoustic Sensing on Overhead Power Lines: Analysis of Electric and Magnetic Field Interference.

The assessment of the acoustic emission from overhead power lines (OHL) has become an important task for OHL grid operators. However, measurements on high-voltage lines present a challenging task. Beside the high voltage, significant electric and magnetic field exposure has to be considered for the design of the measurement system. No autarkic measurement system for line based OHL sound emission measurements exists yet. In this work we investigate the feasibility for the application of MEMS based microphone technology for acoustic emission sensing on OHLs for a future OHL based measurement system. We study the IM69D130 MEMS microphone and analyse its properties with respect to strong electric and magnetic field exposure as it appears in OHL applications. The results indicate the feasibility of this microphone type. No susceptibility with respect to electric fields is found. For magnetic fields a minor susceptibility is found, which depends on the orientation of the microphone.