Development of an Integrative Rotary Test Instrument for AC/DC Hybrid Electric Field

An integrative rotary test instrumment for DC electric field,AC electric field and AC/DC hybrid electric field is developed.Firstly,the relations between the output current of the developed integrative rotary test instrumment and the DC electric field strength,the AC electric field strength and the AC/DC hybrid electric field strength are derived;on this basis,a subsequent processing circuit for the induced signal is designed by narrow band-pass filtering to separate the DC component from AC component in the induced signal.The developed electric field tester is calibrated and field performance tests of the developed electric field tester are performed.The developed electric field tester possesses following advantages of high measuremnt accuracy and high linearity,and can be used to measure the AC electric field,DC electric field and AC/DC hybrid electric field at the same site simultaneously,so it is available to the research on bybrid electric filed in the environment of EHV/UHV transmisssion lines using the same corridor and to the research on bybrid electric filed in the environment of multi-circuit EHV/UHV transmission lines on the same tower as well as for the monitoring of electromagnetic environment.