馈线终端交流采样中的残余直流滤波算法研究

Residual DC filter algorithm in AC sampling based on feeder terminal unit

在配电网自动化系统中,可用馈线终端采集配电网信号,并对配电网及设备进行监测和控制。但是在对配电网进行电压电流采集时,由于传感器、采样电路或外界干扰因素的存在,会对采样值引入不必要的误差,使采集到的信号不准确,影响配电网参数的计量精度,其中,残余直流便是一个不可忽视的误差来源。文中提出一种馈线终端交流采样时的残余直流滤波算法,采用直流滤波器进行残余直流滤波。该算法可根据采集到的电压电流瞬时值自适应地滤除残余直流,使交采得到的电压电流值更加准确,确保配电网参数的计量有更高的精度。针对该算法,利用MATLAB软件进行了仿真研究,仿真结果表明该算法可以有效地滤除交采数据中存在的残余直流分量,具有较强的实用价值。

In the field of distribution automation system, the feeder terminal unit （FTU） is always applied to acquire signals of distribution networks, and to monitor distribution networks and control equipment. However, due to the existence of sensors, sampling circuit or outside interruptions, errors are inevitably introduced into sampling values when acquiring voltage and current, thus causing the acquired signals inaccurate and influencing the accuracy of measurements of distribution network parameters. Residual DC is one of introduced errors which cant be ignored. In this paper, a residual DC filter algorithm in AC sampling based on FTU is proposed. This algorithm is able to filter out the residual DC from acquired instantaneous sampling values, making data more precise and ensuring measurements of distribution network parameters more accurate. MATLAB software was applied to simulate this algorithm and the simulation results showed a good effect of filtering out residual DC from AC sampling values, which is of strong practical value.