In this paper, the active and reactive power control for a voltage source controller is presented. This control is performed without any current control loop. Uncertainties in important parameters (impedance of the line) are considered. A cascade sliding mode controller is proposed and designed. Conventional sliding mode control products chattering with high-frequency oscillations. The super twisting algorithm is a special second order sliding mode that reduces chattering, considerably. Therefore in this paper, two super twisting sliding mode controllers are used in cascade to control active and reactive powers. The designed control is compared with conventional sliding mode in the proposed cascade scheme. This controller regulates powers fed to grid and load, despite parameters uncertainty. Simulation results are obtained to show the capability and effectiveness of the propoesd control.

Keywords: Active and reactive power, Parameter uncertainty, Cascade sliding mode controller, Super twisting algorithm