Real-time synchronous acquisition of wide-area information is the key technology of realizing panoramic information acquisition in the intelligent substation. Based on a study of global positioning system (GPS) sampling data synchronization

a method of realizing closed-loop calibration system of synchronous sampling clock based on the field programmable gate array (FPGA) is proposed to make up for the inadequacy of synchronous sampling clock’s high dependence on the oscillator clock in conventional merging unit and relatively larger output error in the case of aging of the oscillator and reduced accuracy of frequency. By analyzing the output errors of two synchronous sampling clocks quantitatively

it is revealed that the output error can be reduced by software compensation using this method

which ensures accordance of the output phase as well as improves accuracy of the synchronous sampling pulse output. It is verified that the synchronous sampling value of the merging unit can meet the 0.2 s class accuracy standard when an ordinary quartz oscillator is used

reflecting good synchronization.