Patent ID: 9383390
Filing Date: 2016-07-05
CPC Classification: G01R

Claim Text:
1. An AC or DC power transmission system comprising a first electrical conductor, a second electrical conductor and an insulating space between said first electrical conductor and said second electrical conductor, said power transmission system further comprising an electric field measurement device, said electric field measurement device comprising: a housing made of dielectric material and defining a first open end and a second open end opposite said first open end; a first optical fiber received in said first open end of said housing and configured for connection to a light source; a first optical lens mounted in said housing adjacent said first open end and in optical communication with said first optical fiber; a circular polarization filter mounted in said housing in optical communication with said first optical lens; a crystal rod having electro-optical properties received in and encapsulated within said housing in optical communication with said circular polarization filter; a linear polarization filter mounted in said housing in optical communication with said crystal rod; a second optical lens mounted in said housing adjacent said second open end in optical communication with said linear polarization filter; and a second optical fiber received in said second open end of said housing in optical communication with said second optical lens, said second optical fiber being configured for connection to a light detection unit; wherein a continuous light path is defined within said housing from said first optical fiber, through said first optical lens, said circular polarization filter, said crystal rod, said linear polarization filter, and said second optical lens to said second optical fiber; and wherein said electric field measurement device is located adjacent to said first electrical conductor within said insulating space so as to define a first minimum distance between said crystal rod and said first electrical conductor and a second minimum distance between said crystal rod and said second electrical conductor, said second minimum distance being at least 10 times larger than said first minimum distance.