Magnetic-field CMOS microsensor for low-energy electric discharge detection

Abstract

This paper addresses the development and characterization of a non-intrusive silicon-based microsensor, which can detect electric partial discharges in electrical insulation equipment. Early partial discharge detection prevents failures and can be used to optimize maintenance operations. Despite the potential that CMOS technology offers, miniaturized electric discharge detector has neither been investigated nor implemented, until now. The developed microsensor demonstrates its ability to record electric discharge emission thanks to the presence of a miniaturized planar inductor. The squared inductor of 50 turns with a side length of 1.5 mm used in our sensor has been fabricated on top of a silicon substrate in a CMOS technology. The total inductor wire length of loop antenna is 30 cm to achieve 100 MHz bandwidth. Using the microsensor at 1 cm from the discharge site, a damped sinusoidal induced voltage with an amplitude of 2 V has been measured at its output. We observed that the output signal spectrum is highly concentrated around a central resonance frequency, which remains constant. The main advantage of such design resides in its monolithic integration added to the high autonomy, which improves the microsensor efficiency.