Fibre-optic voltage sensor using an optical lever

A new type of linear voltage sensor, able to measure constant and alternating voltage in a wide frequency and amplitude range, is presented. The sensor is based on a bending piezoelectric-motor element with an optical fibre attached to it. The deflection of the fibre is sensed by an optical lever and a linear position photosensor. The sensor has a dynamic range of over three decades (71 dB), linearity error less than 0.1% and variable upper amplitude and frequency range. The simple and flexible design allows the proposed sensor to have almost any desired response and sensitivity. It is used mainly for monitoring constant, low- and medium-frequency voltages in power-utility applications.