Nowadays, FACTS devices are among the most promising electrical network technologies. The typical representatives of parallel FACTS devices are a static synchronous compensator (STATCOM) and a state var compensator (SVC). The paper deals with the issues of modeling SVC and STATCOM when solving the problem of power system state estimation. The algorithms developed by the authors for embedding the SVC and STATCOM models in the state estimation problem are presented. The paper considers the results of calculations using the algorithms devised for a section of the 500 kV network of the Irkutsk electric power system. A comparative analysis of the obtained results is made.