晶振信号同步GPS信号产生高精度时钟的方法及实现

GPS接收机输出的秒脉冲信号存在较大的随机误差，但不存在累计误差。晶振时钟信号的随机误差较小，但存在较大的累计误差。文中根据GPS时钟信号与晶振时钟信号精度互补的特点，建立了晶振信号同步GPS信号的一元二次回归数学模型，估计出GPS时钟随机误差的统计方差和晶振的累计误差；对晶振时钟进行实时修正，产生高精度时钟，并预测了修正后的时钟精度。高精度时钟发生装置已成功地应用于电力系统暂态变化过程的异地同步记录。

CLOCK OF HIGH ACCURACY IMPLEMENTED BY CRYSTAL OSCILLATOR IN SYNCHRONISM WITH GPS-CLOCK

GPS-clock received via GPS receiver has large random error but no accumulative error. Crystal oscillator has small random error but large accumulative one. Based on the complementarity of errors between GPS and crystal oscillator, a quadratic regression model for crystal oscillator in synchronism with GPS-clock is proposed. The statistical deviation of squares of random error of GPS-clock and the accumulative error of crystal oscillator are estimated. With the accumulative error compensated, clock of high accuracy is produced. And its precision is evaluated. A prototype of clock of high accuracy is also developed in a cost-effective way and applied in synchronous acquisition of record of power system transient change in different places. This project is supported by National Natural Science Foundation of China (No. 50207001) and Natural Science Foundation of Hunan Province (No.01JJY3025).