交流电信号有效值高精度测量算法研究

Research on RMS High-precision Measurement Algorithm for AC Signal

在交流电信号的测量设备中,大部分采用同步交流采样技术,它是提高交流采样性能的关键技术。针对现有减少同步误差方法的局限性,分析了采样周期与信号周期不同步以及采样时间间隔不均匀测量误差的问题,采用了累加单元减小量化误差,并结合"三点法",实时跟踪信号频率变化并调整采样周期。研究了使用梯形法计算交流信号有效值时的误差大小以及表达式,采用了改进的参数算法。仿真实验结果表明该算法能有效提高同步采样法测量有效值的精度。

Synchronous AC sampling is a key technology to improve the performance of AC sampling,which is mostly adopted in equipments for measuring AC electrical signal. As existing methods have their limitations to reduce syn-chronization error, this article analyzes the causation of the problems that sampling period is not synchronized veith the signal cycle and sampling intervals are uneven. So accumulation-unit is used to reduce the quantization error in this article, which is combined with three-point method to track the frequency of a signal and adjust the sampling period. After the magnitude and expression of the error are researched, the improved parameter algorithm is introduced when using the trapezoidal method to calculate the RMS of AC signal. The simulation results show the algorithm can effec-tively improve the accuracy of measurement of valid values of synchronous sampling method.