Pockels high-voltage measurement system

The practical use of optical sensors to measure direct high voltages can be limited by their high sensitivity. A new optical high voltage measurement technique for applying to high voltage levels up to 400 kV in a wide bandwidth between dc to 30 MHz is developed. A prototype of the optical voltage transformer is assembled using Pockels crystals in multisegmented arrangement, a super luminescent diode (SLD) light source and a special optical fiber link. A good performance of linearity and accuracy is obtained for dc, ac, lightning impulse, and step voltage measurements. In addition, an excellent agreement is observed between the measured and predicted values.