The main goal of this article is to compare the accuracy of the extrapolations time phase coincidence for the selected methods. In the comparing analysis selected the method using calculable function, polynomial function and linear function. The general idea of synchronization proceed in electrical power system is presented. The most important work conditions during realization of this proceed are mentioned. The most important is the realization of phase condition. Incorrect realization of the phase condition may causes numerous consequences, from power impact and current compensatory impact till loose of synchronous work. For this reason known methods of extrapolation of the time phase coincidence are recalled and their pros and cons are described. Next a new non-linear method of extrapolation of the time phase coinci¬dence realized by calculable function is presented. Then the comparison analysis of the selected methods is made. As the comparative criterion the time phase error is taken. The methods were tested for different parameters concerning frequency difference of voltages synchronizing power objects. One of the testing data set obtained from the mathematical model of the control speed angle unit for water plant with long pipes and large difference water levels. This gives the rigorous testing conditions because of the dynamic changing frequency difference. The values of the numerous tests done on the testing device showed that the new method results in better performance parameters. The paper includes the most important results of the comparative tests. Conclusions and final summary are made.