【作者】 罗苏南；

【导师】 叶妙元；

【作者基本信息】 华中科技大学 ， 电气工程， 2000， 博士

【摘要】 组合式光学电压/电流互感器（COVCT）是一种光机电一体化的新型电力互感器,它克服了传统电压、电流互感器的许多缺点,并集电压、电流测量于一体,在电力系统中具有广阔的应用前景。本文在全面分析和总结COVCT发展历史和现有技术水平的基础上,针对实用化要求,确定以无电容分压器型COVCT、反射式横向调制光学电压传感器及正交双全反射光学电流传感器为研究重点,研制出国内首台220kV COVCT,试验表明其性能达到国外同类产品的水平。本文在分析Pockels电光效应传感机理的基础上,首次利用矩阵光学的方法对光学电压传感器的工作原理进行了系统地阐述,提出了构成光学电压传感器的三条基本准则。利用电磁波理论分析了电光晶体中双折射对测量的影响并阐述了双光路补偿原理。本文首次对反射式横向调制光学电压传感器进行了详细分析,指出了原有结构的不足,并提出一种具有双光路互补效果的新型传感器结构。实验表明,作者提出的新型传感器结构具有较好的双光路温度互补性,使光学电压传感器的稳定性提高了一个数量级。从光学器件、光路结构及信号处理电路等方面首次对影响光学电压传感器稳定性的因素进行了详细分析,为研制实用化光学电压传感器提供了理论指导。提出了进一步改进光学电压传感器稳定性的措施。对光学电压传感器的温度稳定性和时间稳定性进行了大量的实验研究,实验表明,我们研制的光学电压传感器已接近实用化水平。在分析Faraday磁光效应传感机理的基础上,对光学电流传感器的工作原理进行了系统地阐述。建立了反射相移及双折射对光学电流传感器性能影响的数学模型,并对其进行了计算机仿真。对影响光学电流传感器稳定性的因素进行了详细分析,为研制实用化光学电流传感器提供了理论指导。对光学电流传感器的温度特性及线性度进行了实验研究,实验表明,我们研制的光学电流传感器已接近实用化水平。针对无电容分压器型COVCT的结构特点,在分析SF₆气体绝缘特性的基础上,设计了COVCT的绝缘结构,并用有限元法对其电场分布进行了分析计算。理论分析及试验结果表明,COVCT绝缘结构设计合理、可靠。对COVCT系统进行了全面试验,试验表明,COVCT的各项性能指标达到了预期的设计要求。更多还原

【Abstract】 Compared with conventional voltage transformers and current transformers, combined optical voltage & current transformers (COVCT) have many advantages, such as simple insulation structure, immunity to electromagnetic interference, no saturation effect, no flammable materials such as oil, and light weight etc. A COVCT can measure high voltage and large current simultaneously. The emphasis of this dissertation is put onto the study of the COVCT without capacitor divider, the reflection-type transverse modulation optical voltage sensor and the orthogonal dual-total-reflection optical current sensor by summarizing and analyzing the results obtained in literature. A novel 220kV COVCT has been developed.The principle of an optical voltage sensor based on the Pockels electro-optic effect is described in detail. The basic norms of constructing an optical voltage sensor are proposed. The effect of birefringence on optical voltage sensor is analyzed, and the principle of dual-light-channel compensation is described.The reflection-type transverse modulation optical voltage sensor is analyzed in detail for the first time in this dissertation, and a novel optical voltage sensor with dual-light-channel temperature compensation is proposed. Experiments showed that the stability of the novel optical voltage sensor was improved distinctly.The reasons of affecting the stability of the optical voltage sensor are analyzed in detail by analyzing the devices, structure and electronics. The methods of improving the stability of optical voltage sensor are proposed. Some experiments about the stability of the optical voltage sensor have been done. These experiments showed that the stability of the optical voltage sensor is excellent.The principle of an optical current sensor based on the Faraday magneto-optic effect is described in detail. The mathematics model of the effect of reflection and birefringence on the optical current sensor is constructed and simulated. The reasons of affecting the stability of the optical current sensor are analyzed in detail. Some experiments about the temperature characteristics and linearity of the optical current sensor have been done. These experiments showed that the characteristics of the optical current sensor are excellent.The insulation structure of the COVCT is designed by analyzing the insulation characteristics of SF6 gas. The electric field distribution of the COVCT is calculated using the Finite Element Method (FEM). A series of tests including ratio error, stability, and insulation characteristics have been done to test the COVCT system.更多还原