Abstract：DC component is a vital factor which affects the accuracy of measurement. In order to filter out the DC component in the non-synchronous sampling, a method of filtering the DC component is proposed while using the RMS algorithm to calculate the effective value. This method uses the trapezoidal integration principle to divide sampling points in one cycle into integer points and points, and calculate the area of the integer points and the points to calculate the DC component, in the case of system frequency and sampling frequency deviation. Using the linear interpolation algorithm to obtain the sampling value of the fractional point. The proposed method does not need hardware frequency tracking circuit. Data window length is only one fundamental cycle. This method is suitable for a variety of computer protection and monitoring device. Actual device operation shows that this method can effectively remove the DC component and improve the measurement accuracy when the system frequency changes between 45~55Hz.
王霄翔, 程立, 熊慕文. 一种非同步采样下的微机测控装置直流滤波方法[J]. 电气技术, 2016, 17(6): 142-145.
Wang Xiaoxiang, Cheng Li, Xiong Muwen. The Method for Filtering the DC Component of Microcomputer Bay Control Unit with Non-synchronous Sampling. Electrical Engineering, 2016, 17(6): 142-145.
2016, Vol. 17 
