共查询到19条相似文献,搜索用时 15 毫秒
1.
Bulk-optic current sensors have been developed for electric power systems. This current sensor has a glass ring type Faraday
cell, where a light beam circulates around a current-carrying-conductor to precisely measure the current. Fundamental performances
and practical applications are described. 相似文献
2.
Kiyoshi Kurosawa 《Optical Review》1997,4(1):A38-A44
This paper describes development of the optical current transducers using flint glass fiber as the Faraday effect sensing
element. Excellent polarization properties of the fiber with low birefringence are described, and the design and test data
of a current transducer using the fiber manufactured for use in electric power facilities are reviewed. Experimental results
on flexible characteristics of a scheme with round trip light transmission in the fiber is also reported. 相似文献
3.
4.
混合型大电流光纤传感器的研究 总被引:3,自引:1,他引:2
本文叙述了混合合型大电流光纤传感器的工作原理及制作方法.以LED作光源、PIN作接收、火石玻璃为磁感应材料、多模光纤作导光波导的混合型大电流光纤传感器,用于监视高压电网系统中的电流.适用范围10~2~10~4A,精度±0.5%. 相似文献
5.
The temperature characteristics of linear birefringence and its effect upon the output of a bulk glass current sensor is theoretically analyzed and simulated. The results show that when temperature field distributes evenly, the linear birefringence induced by the mutual pressure between sensing head and surrounding material of the package is the main factor, the sensitivity of the system could be varied more than 1% during changes of temperature within the range of −40–40 °C. These results might be useful to those studying optical glass current sensing techniques. 相似文献
6.
Two types of optical current transducers (OCTs) have a bulk Faraday sensor inserted into the gap of an iron core and a porcelain
insulator with optical fiber. The sensor consists of Bi12SiO20 (BSO) single crystal, a polarizer, and an analyzer. The OCTs satisfied the target performance requirement for fault location
and metering and demonstrated maintained performance at some power utilities in Japan and the US. We have developed a fault
location system that immediately detects the fault current with the OCTs, there by locating the fault section. The OCT can
easily replace the existing support insulators for the disconnecting switch without any modifications to structure height
or bus-bar. For metering requiring 0.3% class accuracy, use of a BSO with right optical rotatory power combined with BSO with
left optical rotatory power results in a Faraday sensor with improved temperature characteristics. The OCT demonstrated 0.3%
class accuracy for metering described in the current transformer Specifications of IEEE C57–13, 1993. 相似文献
7.
The dispersion properties of the linear birefringence inside the glass current sensing head of a bulk glass optical current sensor and its effect upon the sensitivity of the sensor are theoretically analyzed and simulated with a computer. The investigation results show that the effect is small enough to be ignored, although it can certainly affect the scale factor of the system slightly. These results might be useful for the researchers and designers working in the optical current sensing techniques area. 相似文献
8.
The dispersion properties of the reflection-induced retardance of polarization-preserving reflecting medium layer and the Verdet constant of the ZF-7 optical glass and their joint effect on the sensitivity of a bulk glass optical current sensor are theoretically analyzed taking the Jones’ Matrix as a mathematical tool and using simulation with a computer. The investigation results show that the dispersions will significantly affect the scale factor of the system. Therefore, it is necessary to stabilize the driving current and the ambient temperature of the optical source by some technical means to ensure the wavelength stability. These results might be useful for the researchers and designers working in the optical current sensing techniques area. 相似文献
9.
在传统光学电流传感器技术的基础上,提出了一种四光路光学电流传感器,其通过四路输出信号可准确确定偏转角,使电流的测量范围不受正弦函数的单调性的限制,从而提高了电流的测量范围。配合四光路结构,提出了新的反正切函数数据处理方法,其不存在角度不灵敏区、可纠正原始数据的缺陷,从而提高了测量精度。实测了充电电压为4.5 kV、电容为50 μF和导线有效穿过磁光探头14次的快开快门的总短路电流,其峰值达85 kA,与理论值87 kA能较好地吻合,从而证明了四光路光学电流传感器可有效地测量脉冲大电流。 相似文献
10.
A galvanogyroscopic effect which is the rotational analog of the gravitomagnetic Hall effect has been proposed. As a consequence
of Ohm’s law in the rotating frame, the effect of the Coriolis force on the conduction current is predicted to give rise to
an azimuthal potential differenceV
gg about 10-3V in a spinning rotor carrying radial electric currenti
r. The potential difference developed by the galvanogyroscopic effect is proportional both to angular velocity Ω and to the
electric current. 相似文献
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12.
介绍了光学电流测量技术的发展情况,描述了目前几种主要的互感器结构及其基本原理,并对各自存在的问题及解决途径进行了讨论。从研究现状来看,块状玻璃型传感器技术相对成熟,已经有商业产品问世;混合型传感器测量精度较高,但传感头有源电路的供电技术复杂,还没有圆满的解决方案;全光纤型是光学电流互感器发展的最终目标,目前存在的主要问题是光纤的固有线性双折射难以处理,有赖于新型光纤材料及集成光学元件的进一步发展。最后综合评述了光学电流互感器技术的发展趋势及产业化前景。 相似文献
13.
Bi‐Cai Zheng Shao‐Cheng Yan Jin‐Hui Chen Guo‐Xin Cui Fei Xu Yan‐Qing Lu 《Laser \u0026amp; Photonics Reviews》2015,9(5):517-522
The unique electronic and mechanical properties, of graphene make it an ideal material for nanoelectromechanical system (NEMS) applications. Here, a miniature optical fiber current sensor based on a quasistatic graphene NEMS with a graphene membrane covering the hole on a pre‐etched fiber tip and two gold electrodes on opposite sides of the tip has been demonstrated. The sensor overcomes the shortcomings of conventional optical fiber current sensors based on thermal effects, such as relatively low sensitivity, long response time, and huge device size; it has simultaneously a high sensitivity of 2.2 × 105 nm/A2, a short response time of ∼0.25 s and a compact device size of ∼15 μm, and has found practical application. Using a smaller graphene membrane with better quality can reduce the response time to submillisecond levels with a more precise measurement system. The sensor presented in this paper may pave the way for the practical usage of optical fiber current sensors based on thermal effects.
14.
Sagnac fiber optic current sensor (S-FOCS) is a kind of optical interferometer based on Sagnac structure, optical polarization states of sensing light wave in Sagnac fiber optic current sensor are limited. However, several factors induce optical polarization error, and non-ideal polarized light waves cause the interference signal crosstalk in sensor, including polarizer, quarter-wave retarder, splice angular, birefringence and so on. With these errors, linearly polarized light wave in PM fiber and circularly polarized light wave in sensing fiber become elliptically polarized light wave, then, nonreciprocal phase shift induced by magnetic field of the current is interrupted by wrong polarization state. To clarify characteristics of optical polarization error in fiber optic current sensor, we analyze the evolution process of random optical polarization state, linear optical polarization state and circular optical polarization state in Sagnac fiber optic current sensor by using Poincare sphere, then, build optical polarization error models by using Jones matrix. Based on models of polarization state in Sagnac fiber optic current sensor, we investigate the influence of several main error factors on optical polarization error characteristics theoretically, including extinction ratio in polarizer, phase delay in quarter-wave retarder, splice angular between quarter-wave retarder and polarization maintaining fiber. Finally, we simulate and quantify nonreciprocal phase shift to be detected in fiber optic current sensor related with optical polarization errors. In the end, we demonstrate S-FOCS in test. The results show that transfer matrix errors are induced by inaccurate polarization properties during polarization state conversion, then, the stability and accuracy of the S-FOCS are affected, and it is important to control the polarization properties at each step of the polarization state conversion precisely. 相似文献
15.
在单层保偏膜式光学玻璃电流传感系统中,费尔德(Verdet)常数、线性双折射和反射相移都是光波长的函数即存在色散特性,因此在采用宽带光源时系统中会产生波长积累效应。先给出了三者的色散特性公式,再对其波长积累效应进行理论分析和计算机仿真。研究结果表明,在所考虑的线性双折射和反射相移的量值范围内,波长积累效应对光学玻璃电流传感系统影响甚微,用单色光模型处理宽带系统的做法是合理的与可行的;光源谱宽变化对系统输出的影响小于0.025%,在考虑三者的联合影响时,Verdet常数色散的影响占主导地位,而且整体上系统输出随光源谱宽的增加而有微弱增加。 相似文献
16.
B. I. Turko V. B. Kapustyanyk V. P. Rudyk M. V. Partika M. V. Kvasnytsya A. P. Vas’kiv 《Journal of Applied Spectroscopy》2007,74(2):310-312
We have studied the behavior of the intrinsic absorption edge in zinc oxide thin films in the temperature range 80–300 K.
We have observed that the intrinsic absorption edge in films with crystal sizes of ≈45 nm or larger is described by the empirical
Urbach’s rule, while in films with crystallite sizes of ≈15 nm, it is described by a modified Urbach’s rule. We have calculated
the effective frequency of phonons taking part in formation of the absorption edge.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 2, pp. 275–277, March–April, 2007. 相似文献
17.
B. I. Turko V. B. Kapustianyk V. P. Rudyk G. A. Lubochkova B. A. Simkiv 《Journal of Applied Spectroscopy》2006,73(2):222-226
We have studied the temperature variation of the intrinsic absorption edge of thin polycrystalline films of zinc oxide, obtained
by high-frequency magnetron reactive sputtering. We ha ve observed that the intrinsic absorption edge in such films is described
by a modified Urbach’s rule. We have calculated the effective frequency of phonons taking part in formation of the absorption
edge.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 200–203, March–April, 2006. 相似文献
18.
Friedhard Römer Bernd Witzigmann Oscar Chinellato Peter Arbenz 《Optical and Quantum Electronics》2007,39(4-6):341-352
Photonic crystal cavities facilitate novel applications demanding the efficient emission of incoherent light. This unique
property arises when combining a relatively high quality factor of the cavity modes with a tight spatial constriction of the
modes. While spontaneous emission is desired in these applications the stimulated emission must be kept low. A measure for
the spontaneous emission enhancement is the local density of optical states (LDOS). Due to the complicated three dimensional
geometry of photonic crystal cavities the LDOS quantity has to be computed numerically. In this work, we present the computation
of the LDOS by means of a 3D Finite Element (FE) Maxwell Solver. The solver applies a sophisticated symmetry handling to reduce
the problem size and provides perfectly matched layers to simulate open boundaries. Different photonic crystal cavity designs
have been investigated for their spontaneous emission enhancement by means of this FE solver. The simulation results have
been compared to photoluminescence characterizations of fabricated cavities. The excellent agreement of simulations and characterizations
results confirms the performance and the accuracy of the 3D FE Maxwell Solver. 相似文献
19.
The piezoelectric film electro-deposition for optical fiber sensor with ZnO coating is studied. The zinc oxide plating film is made on the copper surface directly by cathodic electro-deposition in the Zn(NO3)2 single salt aqueous solution systems. The influences of main experimental conditions on the properties of ZnO thin film in the electro-deposition processes are analyzed and a stable, practical and economic technique is obtained. 相似文献