Modeling the Electrical Capacitance of Monitoring Sensors

A device is proposed for diagnostics of the rotor-shaft eccentricity in an electrical machine. Its sensitivity does not depend on the fluctuations of the grid parameters or the load of the electrical machine, since the rotor displacement is monitored by means of the capacitance of sensors placed uniformly around the circumference at each end of the shaft. The diagnostic results are assessed in terms of two criteria. The device determines not only the eccentricity of the rotor but also its direction of displacement.