Research on the Optical Current-Transformer Applied to Flat-Shape Three-Phase Bus-Bars for Low or Middle Transmission Currents

光学电流互感器（OCT）目前应用较少。近年来，人们开始了对OCT的一些新的研究，以提高OCT的性能和实际应用。这些研究的主要目的是开发出可以集成到断路器等电力设备中的OCT，充分利用OCT的重量轻，尺寸小，隔离性好的优点。本文研究了电流互感器应用于3 kV、6 kV中低压三相电力设备的可能性，提出了母线屏蔽式电流互感器结构，并对其磁场干扰进行了分析。(Year:1996年），它表明，在三相交流领域的相互干扰和涡流的影响，这是问题时，将OCT应用到三相母线设备，可以通过使用所提出的双重屏蔽结构减少。这种结构可以应用于母线的并排布置和纵向布置，而不改变屏蔽的形式。对OCT中磁敏感膜和屏蔽芯等磁性材料的非线性特性引起的孔隙进行了实验研究，并对这些孔隙进行了法师清除。(Year：1997），对模拟的OCT结构进行了实验研究。实验结果表明：（1）无取向S-Fe叠层具有足够的屏蔽效果。(2)本实验制备的（BigdY）_3D_2（FeAl）<12>_5O_2薄膜具有良好的线性M-H特性。(3)认为适当选择交流光探测器可以消除这种微小的波形畸变，为减小光传输损耗，有必要进一步改进场传感器的结构。我们的研究正在继续，以解决这个问题。

The optical current transformaer (OCT) was scarcely used in applications fo far. Recently some new reseaches on the OCT have been begun for its practical application and improbements of performance. The main purpose of those researches is to develop the OCTs that can be incorporated into electric power devices like the circuit-breakers, taking full advantage of the OCT that is light weight, small size and good isolation. We have studied the possibility of applying the OCT to three-phase power equipment used at a low or middle voltage of 3 or 6 kV.In this study, we proposed the OCT sturyucture that has shielding around bus-bars and made analyzes about the interference of magnetic fields.(Year : 1996) It was shown that mutual interference in three-phase ac fields and the influence of eddy currents which are problems when applying the OCT to the three-phase bus-bar equipment can be reduced by using the proposed duoble shield structure. This sturcture can be applied to both the side by side and the longitudinal arrangements of bus-bars without a change in the form of the shield. Porblems originating in non-linear characteristics of magnetic matrials, such as magnetic sensor films and shielding cores, used in this OCT were investigated experimentally and mage them clear.(Year : 1997) We deceloped experimental work on the OCT structure simulated. As a result of this experimental investigation, the following were confirmed : (1) Non-oriented S-Fe laminations exhibit the sufficient shielding effect for this application. (2) The (BigdY)_3D2(FeAl)_5O_<12> film prepared for this experiment shows excellent M-H characteristics on linearity. (3) It is considered that the slight waveform-distrotion can be removed by apporpriately selecting the ac optical detector.It is necessary to improve the structure of field sensor further for decreasing liht transimission losses. Our research is being continued to work this problem out.