The Simulation And Research On One-cycle Control Shunt Active Power Filter

The widespread use of kinds of nonlinear and time-varying electronic devices resultsin more and more harmonic pollution to the power system.As an effective device for powergrid harmonic suppression,active power filter (APF) is used more and more widely.Thedetection and control methods of current are key factors for active power filter which notonly affect the compensation performance of APF, but also affect the extension applicationof APF.Therefore,it has important practical significance which constantly improved theexisting harmonic current detection method and control methods for increasing the APFcompensation performance.One-cycle control is one kind of nonlinear control methods. Its principle is to controlthe duty-ratio of switch to make the average value of switch variable of the switchingconverter equal to or proportional to the control reference in each cycle, so that steady-stateand dynamic-state error can be eliminated effectively.But traditional one-cycle control APFhas also many shortcomings so that this method has certain limitation.In order to overcome harmonic and reactive current can only be compensated at thesame time and it can’t be used when the source voltage distortion.The current detectionbased on cycle reset integration method is added in this paper. The method has realized theharmonic and reactive current flexible compensation and the compensation results are notaffected by the source voltage distortion,In order to overcome the current contains dc component after compensation and thecontrol strategy are greatly influenced by system parameters.The control equation is built inthis paper.The corresponding circuit is set up, the circuit is simple, reliable and easy toimplement.The simulation model are built by Matlab/Simulink software in the single-phasedsystem and three-phased system.Simulation results are compared with the traditionalone-cycle control’s.The simulation results confirm that the one-cycle control method basedon the current detection has a good compensation performance and there is more widerapplication.This method has a good development prospect.