模拟量输入合并单元无同步信号校验技术

Calibration Technique in the Absence of Synchronization Signals for Merging Units with Analogue Input

为了实现使用固定延时法校验模拟量输入合并单元的测量准确度,提升新一代数字化变电站检测技术水平,设计了一种基于高精度数据采集卡的无同步信号校验系统。在系统的结构设计中,利用合并单元严格的工作时序,数据处理方面研究了基于小二乘拟合的数据同步方法。分析了校验系统的测量不确定度,并使用所设计的校验系统测试了模拟量输入合并单元。将测试结果与采用同步脉冲法校验的结果相比较,结果显示两种方法所得的比差的差异<0.02%,角差的差异最大约为4′,与已有的相关测试结果相符合。这表明该设计方案是可行的,所设计的校验系统可以满足无同步信号校验模拟量输入式合并单元的需求。

To calibrate merging units with analogue input by using the fixed time-delay method and to promote the level of test technique for intelligent substations of new generation, we put forward a calibration system independent of signals based on high-accuracy data acquisition cards. In the process of structure design, strict working timing of the merging units is utilized, and in the aspect of data processing, data synchronization method based on least-square fitting is researched. Moreover, measurement uncertainties are presented, and the designed system is employed to test the accuracy of a merging unit wish analogue input. Comparison of the results obtained through two different test methods shows that the differences of ratio errors are below 0.02%, and the maximum difference of phase errors is about 4＇, which are in conformity to the existing test results. This indicates that the design scheme is feasible, and the designed calibration system meets the requirements of calibrating merging units with analogue input without using synchronization signals.