This paper presents a control algorithm of 3ph STATic synchronous COMpensator (STATCOM). The algorithm depends on the accurate reference currents extraction from only the nonlinear load current spec-trum in frequency domain using Fast Fourier Transfer (FFT). Then the determined harmonics and reactive components of load current are added together to form the compensating reference signals, the PI controllers then generate signals which control the Pulse Width Modulation (PWM) method. The simulation of the study is carried out under MATLAB/Simulink environment to show the usefulness of this control algorithm with nonlin-ear dynamic loads. It determines exactly the phase shift between the power system current and source voltage using only load current measurement. It is also able to calculate accurately the harmonics presence in source current. Various simulation results are presented with many modes of operation of dynamic nonlinear reactive loads. The results show a perfect damping of harmonics and reactive power compensating. The current Total Harmonic Distortion (THD) maintains the IEEE STD 519 Standard and power factor is almost 1, the STATCOM also has a fast dynamic response for transients.
STATCOM, FFT, Power Factor correction, Harmonic mitigation, Harmonic extraction, THD, IEEE STD 519, controller, STATCOM control system.