Resistively shielded optical voltage transducer

A high-voltage (HV) optical voltage transducer (OVT) using resistively shielded electric field sensors is presented for use in HV transmission systems. The OVT is built in a hollow-core polymer insulator filled with low-pressure dry nitrogen gas. A 138 kV prototype has been tested for accuracy under various severe dynamic field disturbances including salt-clay pollution (clean fog test) and melting ice on the insulator. The test results show that the OVT meets ANSI/IEEE 0.3 % accuracy classes under these extreme field disturbances. The prototype has also been tested and successfully passed various HV dielectric tests including lightning impulse tests (BIL) at /spl plusmn/650 kV, chopped impulse tests at -750 kV, power frequency withstand at 275 kV, and partial discharge <5 pC.