Characteristic of capacitive sensor for the air gap control system in the hydrogenerator

In this paper was proposed a capacitive sensor with coplanar parallel electrodes for measure the air gap between the stator and rotor in the hydrogenerators. The effects of influence of some technological errors on accuracy of measurement purposed capacitive air gap sensor has been analyzed. The design scheme and analytical dependences for the error identification because of inclination of sensor electrodes plane relatively to the pole surface of the rotor have been created. The additive error of measurement of air gap caused by the influence of curvature of the surface of the stator core bore has been calculated. Recommendations to minimize the influence of technological error on accuracy of measuring the air gap in the hydro generator have been developed.