A sampling synchronization method adapt intelligent substation for line optical differential protection

In intelligent substation, line optical fiber current differential protection exist two sampling data method which is point-to-point and network transmission, but the opposite substation may be the traditional substation or may also be equally intelligent substation. This paper presents a case for the current difference of optical fiber protection device for synchronized sampling method, protection in traditional substation is a sampling and processing unit as one form of protection that a special protection of intelligent substation. By adjusting the data transmission on both sides of the fiber channel interrupt time, so that data transmission is synchronized at both sides. On both sides, calculation of delay of data sampling synchronization at fiber channel data transmission time for time basis, then this side of the sampling delay is sent to the opposite side. According to both sides of the comparisons of the maximum sampling delay, the differential protections can synchronous data sampling. The last line is proposed to adapt to Multi-terminal differential synchronization principle. The method has been applied to practical engineering.