The new data processing method with suppressing the interference signal in phase measurement

Phase is a fundamental electrical parameter, at present the common method to measure phase is pulse counting method. But the interference and DC bias in the phase measurement process will reduce the measurement accuracy. This paper provides a new data processing method with anti interference ability in phase measurement based on the digital logic technology, it designs the special event capture and data storage circuit by FPGA. Its basic principle is recording the zero-crossing point time series of measured signal with the interference or DC bias in detail. Then by the data processing method, it takes the mean value of the zero-crossing jitter moments as the equivalent stage change moments to eliminate the zero-crossing jitter. It also takes the average value of the rise edge moments and falling edge moments as the equivalent rise edge moments and falling edge moments to reduce the quantization error of pulse transformation technology. Because the positive and negative pulse widths of the normal sine wave are equal, it corrects the rise edge and falling edge moments of the measured signal by the above theory to eliminate DC bias. Then by MATLAB software, it makes the analog simulation to verify the feasibility of this phase measurement method provided in the paper.