高精度组合型电子式电流/电压互感器测量技术研究

Research on the Technology of Precise and Combined Electronic Current/Voltage Transformers

针对电子式互感器模拟器件易受温度、环境等因素影响的问题和其对电流、电压测量中节省空间和器材要求,本文介绍了一种电子式电流/电压互感器共用一套绝缘支柱的组合型设计,它采用SF_6绝缘技术,利用高压壳体与接地金属屏蔽罩的双重屏蔽作用提高抗电磁干扰能力和稳定性,采用Rogowski线圈作为被测电流的计量、保护传感元件,取消了光供电系统,通过基于直流负反馈原理的改进Al-Alaoui数字积分器来抑制输入信号中直流分量的影响,改进的数字积分算法频率特性接近于理想积分器的频率特性,试验结果显示,该组合型电子式电流/电压互感器具有较高的准确度和稳定性。

The electronic transformer was easily affected by temperature, environment and other factors. To solve this problem and satisfy the requirement on saving space and current/ voltage measured equipment, a combination design of sharing insulation pillar by electronic current/voltage trans-forms was introduced in this study. SF_6 insulation technology was employed. Double shielding effects of high pressure shell and grounding metal cover improve the ability of anti-electromagnetic interference and stability. The air-core coil was adopted to measure current and as protecting sensors. Optical power supply system was cancelled. Through the improved Al-Alaoui digital inte-grator on the basis of the principle of direct current negative feedback, the effect of direct current in input was suppressed. And its frequency characteristic was closed to that of the ideal integrator. Experimental results show that the combined electronic current/voltage transformer has high accuracy and stability.