电网工频信号非整周期采样误差分析

Error analysis of non-integer-period sampling for electric sinusoidal signal

交流信号采样过程中存在着很多误差源,非整周期采样是一种重要的误差源,由于电网频率的波动,实际工程应用中整周期采样难以实现,用非整周期交流采样测量正弦信号的有效值和有功功率的大小,存在着比较大的测量误差。本文从时域角度对其研究,推导非整周期采样时域误差公式,建立非整周期交流采样测量电压电流信号有效值和有功功率的误差数学模型,分析每个参量变化对同步误差影响的大小,找出主导因素,为减少测量误差提供理论依据。

There are many error sources in sampling of A.C.singal non-integer-period sampling lead to large error.Integer-period sampling of AC singal is hardly to achieve.Error is generated because of non-integer-period sampling, to calculate the rms of AC sinusoidal singal and the value of active power. In time domain, The error is analyses, the formula of the error is derived and the mathematical model is built . The effects of each factor for synchronization error is analysized, and the main factor is founded,which provides a theoretical basis for improvement measures to reduce the measurement error.