PROTECTING THE WIDEST RANGE OF HYDRO GENERATORS AND MOTORS

Sensonics, a leading supplier of Turbine Supervisory and High Integrity Protection Equipment industry with nearly 50 years of experience, have recently expanded their range of Capacitive Air Gap Sensors for use in high magnetic field applications.

Their CS probe / CSD driver combinations are now available in an increased measurement range, covering 15mm, 25mm, 30mm, 50mm or 70mm to ensure highly effective monitoring for the smallest, up to the largest hydro generators.

Developed for use on large electric motors as well as hydro turbine generators, the sensor provides a rotor to stator air gap measurement which can be used to monitor both the eccentricity of the rotor relative to the stator and individual pole to stator air gaps.

The CS sensors are designed as a non-contact dynamic position transducer utilising a capacitive technique to provide an accurate displacement measurement from the sensor face to a metal target.  The advantage of the capacitive technique in generator applications is the high immunity to magnetic fields; the CS series also provides high resolution and relative insensitivity to different (metal) target materials.  

The sensor is available in a robust strip-line mechanical arrangement, ideal for mounting on the stator wall. It features separate transmit and receive integral coaxial cables which are routed over the stator wall or through ventilation holes to the driver which provides the transmission signal for the strip line and receiver detection. 

Linearised opto-isolated outputs are provided in both voltage and current format which can be configured to represent various rotor pole measurements with respect to the stator. These include pole and rotor profile as well as an overall minimum gap output. 

More at: https://www.sensonics.co.uk/blog/capacitive-air-gap-sensors-how-used