应用于空心线圈电子式互感器的双环数字积分器设计

目前空心线圈电子式互感器多采用硬件积分器,受硬件元器件输出误差及系统扰动影响,硬件积分器在特定情况下存在失真问题。文中提出了一种数字积分器设计方案,该方案采用两个修正环节来调节积分器输出的直流分量:AD采样输出正向调理环节和积分器输出反馈调理环节。AD采样输出正向调理环节主要用于消除电子元器件输出直流偏移;积分器输出反馈调理环节用于调节最终输出的直流分量,其中包含了前端残余直流分量和数据精度误差经长时间累积产生的直流分量。为防止系统扰动时对一次直流分量误修正,对信号调理限定条件进行了分析。通过实验验证,表明该数字积分器对正常电流及各种扰动电流均能够精确跟踪,保证了电流数据的测量精度。

Dual Loop Digital Integrator Design for Rogowski Coil Electronic Transformer

At present the Rogowski coil electronic current transformer adopts the hardware integrator, but affected by the disturbance of hardware components output errors and the system disturbance, hardware integrator has the distortion problem in specific situations. This paper presents a scheme of digital integrator with two correction links to adjust the DC component in the output of the integrator: the AD sampling output forward conditioning link and the integrator output feedback conditioning link. The AD sampling forward conditioning link is mainly used to remove the output DC offset of the electronic components and the integrator output feedback conditioning link to adjust the final output of the DC component, which contains the residual DC component from front end and DC component from data accuracy error after long-term accumulation. In order to prevent erroneous correction of DC component at the disturbance of the primary system, a detailed analysis is made of the signal conditioning limiting conditions. Through prototype development and experimental verification, it is proved that for normal current and various disturbances current, the digital integrator can accurately trace the original current, which is helpful to improving the measuring accuracy of the current.