The Research Of Reducing Linear Birefringence For Optical Current Transformer

The optical current transformer is new technique in high-voltage measure field. More recognizer and concern are received for it's non-exploder, non-magnetism saturation, no lagging, light and small .It also mean important to national electric power measure.The reflect phasic movement problem was basically and widely solved, but linear birefringence is blocking optical current transformer's being in utility progress, both fiber optical current transformer and bulk glass optical current transformer.The principle of the Faraday rotation mirror-typed OCT (optical current transformer) is analyzed, further more, the method of reducing the influence of linear birefringence to system output voltage by adding incident light s phase shift intentionally is posed. The theoretical analysis and the conclusion is proven by the result of computer simulation, the rationality and feasibility of the method to reduce linear birefringence's effect is demonstrated. It makes sense to improve the performance of OCT (optical current transformer) and to develop new applied OCT.The effect of OCT output voltage for linear birefringence is analyzed, it's incomplete problem of the examination of output light's information in the difference divided by addition examination system is pointed out, linear birefringence in bulk-glass optical current sensing head cannot be examined separately by the difference divided by addition examination system, it's proved and concluded theoretically by Jones matrix. Bringing forward The elliptically polarization examination system of OCT, the formula to explain the relationship among the thermal induced linear birefringence. The elliptically polarization examination system's completeness for the examination of output light's information is proved, and the thermal induced linear birefringence and electrical current intensity can be tested in the same time The elliptically polarization examination system and difference divided by addition examination system are brought forward for ensuring being in real time. By the time modifying real time output voltage of the difference divided by addition examination system, linear birefringence's effect is conquered and electrical current intensity can be tested in real time, the thermal induced linear birefringence's effect to OCT is solved theoretically.