Adaptive Control of Shunt Active Power Filter

This research work proposes two new adaptive control techniques for three-phase Shunt Active Power Filter (SAPF); Interval Type-2 Fuzzy Control (IT2FC) and Adaptive Backstepping Nonlinear Control (ABNC). The proposed methods have been compared with conventional linear and nonlinear controllers such as PI and type-1 fuzzy controllers. The simulation results show that the proposed methods improve transient response and reduce THD in both line currents and voltages under the conditions of parameters uncertainties step load change and unbalanced load currents. However ABNC provides better current tracking and DC voltage regulation performance than IT2FC. In addition it provides robustness of performance against step change of load and frequency variations. Moreover due to the adaptive nature of ABNC it is possible to work without DC voltage sensor to obtain the permissible limits of THD in line currents and voltages under the same conditions. The experimental implementation proposed new current control strategy for SAPF in the stationary a-b-c frame. This method was proven to be feasible approach for design with new version of the inverter model using Freescale DSP56F807.