| Abstract |
A LCL grid connected three-phase and three-wire shunt active filter (SAF) is studied andcontrolled. It is known that SAFs generate distortive components caused by a high switchingfrequency of a voltage source inverter (VSI). In order to prevent spreading these distortivecomponents to the grid, the LCL filter (usually controlled by a linear control feedback) is used;while a parasitic phase shift/lag between the reference and injected currents emerges andseverely deteriorates the filtration quality. On the other hand, the use of a sliding modecontroller (SMC) reduces phase shift effects and consequently ensures good filtration qualityof the SAF while improving robustness to system's disturbances. A side effect of SMC is ingenerating discontinuous very high switching frequency control command that can severelyhurt the switching elements of the VSI. In this work, the robust continuous higher order slidingmode controller (C-HOSM), whose output is processed by pulse-width modulators (PWM), isstudied for controlling the SAF. The proposed robust control set up provides a fixed givenfrequency of control switching, required for the VSI safe operation. The proposed approachwas validated on industrial nonlinear load via simulations carried out using Matlab, Simulink,and Simscap-Sim\_Power\_System code. |
