The work is devoted to the study of performance of a multilevel electric energy converter using phase-shifted pulse-width modulation. Equations describing the state of a dynamic system multilevel converter - load are investigated and a mathematical model of the system in Matlab / Simulink environment is constructed. Variants of implementation of phase-shifted pulse-width modulation systems from the point of view of influence on harmonics of output voltage and magnitude of circulating current in the converter are investigated.