高准确度的超低频交流电压表设计

摘要

This paper analyzed the measuring methods of the ultra-low-frequency AC voltage signal,and designed a measuring method based on sampbng-calculation. Designed the hardware circuit structure of the ultra-low-frequency AC voltage meter based on high-speed precision A/D converter and high-performance DSP processor, and designed the synchronization algorithm for non-synchronous sampling based on linear interpolation, and designed the RMS algorithm based on the composite trapezoidal quadrature formula. Developed the ultra-low-frequency AC voltage meter, and calibrated and tested its specification.The results showed that the developed ultra-low frequency AC voltage meter measurement frequency limit reached 0. 001Hz, and its measurement uncertainty was better than 0.01％.%分析了超低频交流电压信号的测量方法,设计了基于采样计算方式的超低频交流电压测量方案.设计了以高速高精度A/D转换器和高性能DSP处理器为核心的超低频交流电压表硬件电路,设计了基于线性插值的非同步采样同步化算法,设计了基于复合梯形求积公式的有效值算法.对所研制的超低频交流电压表进行了量值溯源与校准测试,测试结果表明所研制的超低频交流电压表测量频率下限达到了0.001 Hz,测量不确定度优于0.01%.