一种用于基波测量的数字校准方法

A Digital Calibration Method for Measuring Fundamental Components of Phasors

在电力系统中,相量测量的精度主要受到信号采样通道元器件误差和软件采样同步误差的影响。分析和实验表明,不同量程同步采样经幅值校准后拟合的方法改进了相量幅值测量的精度,对各相量进行相位校准的方法克服了相量采样的同步误差。综合应用2种方法,提出了基波相量幅值校正和相位校正的数字校准方法,对输入信号采用不同放大倍数调理电路进行分段处理和A/D采样,经幅值校准后拟合,以及对各相量进行相位校准均改进了电力系统电压和电流的测量精度。最后介绍了该方法在微机保护装置中的应用及其检测结果。

A method of digital calibration for measuring all phasors＇ fundamental components of the power system is proposed. The method is based on double-channel sampling of two signals with different gains from the same input signal, amplitude and phase correction of all phasors＇ fundamental components. The measuring accuracy of all phasors＇ fundamental components is improved by undergoing amplitude calibration and phase calibration and use of the A/D converter and DFT/FFT algorithm. Furthermore, the digital calibration method of amplitude correction coefficient and phase correction coefficient is presented in detail. The results show that the accuracy of the system is improved. Finally, its application to computer protection systems and detection report is described.