【作者】 程云国；

【导师】 刘会金；

【作者基本信息】 武汉大学 ， 电力系统及其自动化， 2004， 硕士

【摘要】 随着电力系统电压等级的提高和容量的增大，传统电压互感器的绝缘困难，频带窄，有燃烧和爆炸危险等缺陷日益突出，直接影响到电力系统及用电设备的安全运行。光学电压互感器克服了传统电压互感器的许多缺点，有广阔的应用前景。 本文论述了用于电力系统高电压测量的基于电光晶体B60的Pockels效应的光学电压互感器的基本原理：在电场作用下，BGO晶体的折射率发生了变化，一束线偏振光入射晶体后分裂成两束光，利用偏光干涉的方法检测出两束光的位相差就可以得到被测电压的大小。 光学电压互感器常用的是横向调制和全电压纵向调制结构，本文对这两种结构抗外电场干扰进行了详细的分析，指出了它们的优缺点，并对纵向调制结构进行了改进，分析表明：改进后的纵向调制结构抗外电场干扰的能力强，信号处理简单，而且把双光路补偿应用到纵向调制结构中，在一定程度上消除了干扰双折射的影响。该结构用直角棱镜代替了普通的四分之一波片，提高了光学电压互感器的稳定性。 光学电压互感器的稳定性一直是影响光学电压互感器实际运用的关键因素。本文对光学电压互感器的稳定性进行了较深入的探讨，从结构、材料等方面讨论了光学电压互感器的误差来源及其处理办法，为研制实用化的光学电压互感器提供了理论指导。 在光学电压互感器中，光纤传导系统起传递信息和绝缘的作用，是不可缺少的部分，也是影响测量精度的一个重要因素。本文分析了光纤的传输特性和光发射与接收组件的性能，并进行了实验研究。实验表明该系统具有很好的线性度，可以在光学电压互感器上使用。 本文还分析了电压互感器准确级对A／D转换器分辨率的要求，设计了以12位模数转换器为核心的数据采集板，实验研究表明，数据采集板的准确性和可靠性是符合要求的。更多还原

【Abstract】 The disadvantages of traditional voltage transformer, such as difficult-insulation, narrow-bandwidth and danger of burning and blast, become obvious step by step with the increasing voltage class and power capacity. It directly affected safety running of power systems. The optical voltage transformer (OVT) overcomes many disadvantages of traditional voltage transformer. It has a great future.This paper discussed the basic principle of optical voltage transformer that measures high-voltage in electric power system. This OVT is based on BGO’s Pockels effect. The refractive index of BGO changes when an electric field is applied to them. Injecting a linearly polarized beam into the BGO causes the beam to be divided into two linearly polarized beams. The voltage applied can be perceived by measuring the phase difference of the two beams with the help of the two polarized beam interferometry.The OVT’s modulators often apply longitudinal and transverse modulators. This paper analyzed their advantage and disadvantage, and improved longitudinal modulators. This analysis shows that the improved longitudinal modulators have high immunity to electric field interference and simple signal process. Furthermore dual-beam-channel compensation method can be applied to longitudinal modulators, which can eliminate the errors arisen from interferefering birefringence to some extent. The structure substituted rectangular prism for common quarter wave, and improved the stability of the optical voltage transformer.The stability of optical voltage transformer is the key to holdback the OVT to be applied to practice. The paper discussed detailedly the stability, the origin of error from the aspect of construction, material et al, and the method of eliminating error. It provided the theoretic direction for OVT’s practical application.The fiber transmission system acts as transferring information and insulation. It is a necessary part of OVT and an important factor of influencing the precision. The paper analyzed the fiber transmission character and the performance of emission and receiving module, and had a trial. The trial showed that this system had a good linearity, and it can be used for OVT.The paper also analyzed the request of the OVT for the A/D converter. We designeda sampling board with a 12-bit A/D converter. The trial indicated that the veracity and reliability of the board accord with the request.更多还原