DJELLAD Abdelhak2025-09-102025-09-102021http://dspace.ensti-annaba.dz:4000/handle/123456789/759Journal Européen des Systèmes Automatisés Vol. 54, No. 4, August, 2021, pp. 519-528 https://doi.org/10.18280/jesa.540401FACTS devices installation is required to guarantee high energy quality and power system stability. The present paper tackles the problem of voltage control, reactive power and power factor improvement in an electric power network by one of the AC transmission devices (FACTS) of the static synchronous parallel compensator type (STATCOM), using serial multicellular converters with different levels (three to six levels). Such converters with special attention paid to the active balancing of capacitor voltages in order to generate good quality waveforms and improve the harmonic content of the output voltage. The controller's ability and functionality are evidenced through a detailed theoretical analysis. We elaborate the compensator's operating model by stating its equivalent electrical diagram representation. This is followed by a mathematical modeling and a control model based on phase shifted pulse width modulation (PS-PWM) technique to monitor reactive power flow inside the system and maintain the voltage at the common connection point (PCC) at a steady value. The proposed system simulation is carried out using Matlab Simulink environment. Finally, a presentation and a discussion of the obtained results are provided.enArticle