Passive optical devices offer valuable technical and economic advantages for power-system current and voltage measurement. Such devices can also be used to measure a variety of other power-system parameters (e.g. temperature, pressure, strain, etc.). The main advantages of all such devices may be summarized as follows:
(i) No powering is required at high voltage points.
(ii) There is freedom from saturation effects.
(iii) They have large measurement bandwith.
(iv) The measurement sensitivity is high.
(v) The costs are low and are not strongly dependent on system voltages.
(vi) They are readily interfaced with interference-immune communications links.