Measurement of Power Frequency Electric Fields from AC Power Lines

Abstract

In recent years, due to increase in power demand, the power system requires EHV / UHV AC and HVDC transmission for bulk power transfer. Design of such type of transmission line network requires estimation of electric field around and under them. The knowledge of electric field helps in designing the insulation system and it plays a crucial role in reliable operation of the power system. The electric field measurement, although quite essential, not easily measurable. It is rather feasible through equipotential line estimation. There could be better ways to establish the field intensity and is done through the electric field mills, field sensor etc., while taking due care of avoiding influence of stray field. There are standard techniques (IEEE-644-1998) are proposed to measure electric field at power frequency from AC transmission line from ground level. Similarly, field mills are employed for HVDC field measurement. The dissertation contains the details of development of similar field measuring approach as per IEEE standard and available literature. Using this measurement devices, the laboratory setup is used to establish field intensity. The same device is used for 11 kV line field measurement. The design, power circuitry and the results are presented.