电参量微机测量中随机误差的分析及抑制

随机误差是影响电参数微机测量精度的主要因素之一，电参量策微机测量的环节诸多，产生随机误差的原因也多种多样，分析了电参量测量中随机误差的产生原因；针对其中原因明确的多种随机误差，如：交流采样同步误差、A/D量化误差、有限字长误差、前置输入通道增益随机偏差等，分别提出了频率跟踪及软件同步改进、适当增加A/D芯片位数及采样点数、数字调零及增益自动校准、采用浮点数或较长定点数等等相应的抑制措施；对其它原因不明、或数量从多难以一一处理的随机误差，提出了剔除不良值、数字滤波等数值处理方法，这些措施和方法可显著减小随机误差，提高测量精密度，且一般用软件即可实现，不增加装置成本，它们大多巳应用于电力智能测控仪器的设计中，并在实践中取得了满意的效果。

Methods of Restraining Random Errors in Computer-based Electric Parameter Measurement

Random error is one of the main reasons that degrades the measuring precision in digital electric parameter measurement. There are many factors that cause random errors in the process of digital measuring. Based on analyzing the factors, some effective methods are presented to restrain the corresponding random errors whose causes are determinated. Furthermore, data processing algorithms are also studied in order to reduce the general unknown random errors. As a result, the random errors are greatly decreased without additional cost due to the software implementation. The feasibility and effectiveness of the proposed methods have been verified by the results of practical applications.