Optimal and adaptive voltage and current harmonics compensation under non-stiff voltage conditions

In this paper the operation of optimal and flexible control (OFC) based active power filters under non-stiff and distorted voltage conditions is investigated. Under these conditions there exist a feedback from the load currents to the load voltages hence this situation makes the OFC based system a closed loop adaptive system which may represent an unstable or poor transient response behavior. By identifying the source equivalent circuit an improved OFC algorithm (IOFC) has been proposed. The proposed control algorithm considers the load voltage variation due to the load current variation. Successful performance of the proposed algorithm has been investigated and proved by several MATLAB/SIMULINK based simulation studies. Also, a new compensation strategy based on IOFC system which minimizes the load voltage harmonics has been proposed and investigated.