Improving Power Quality Using a Fuzzy Inference System-Based Variable Forgetting Factor Recursive Least Error Square Control Scheme of DSTATCOM

A two-layer combined control method is developed for a four-leg Distribution Static Synchronous Compensator (DSTATCOM). The method aims at harmonics reduction, demand-generation equilibrium, power factor modification, voltage adjustment, and neutral current modification in a 3ph 4-wire distribution system. In the first layer, a recursive Least Error Square algorithm (RLES) based on a new fuzzy logic-based variable forgetting factor is used for Real-time estimation of voltage and current signals and their constituting components. The second layer’s duty is to extract the reference currents using the outputs of the first layer. Besides the high accuracy and convergence speed, the suggested algorithm is independent of coordinate transformations and complex computation when attempting to derive the reference currents of DSTATCOM. To enhance the dynamic performance of DSATATCOM, an adaptive hysteresis band current controller was utilized to generate switching signals. The effectiveness of the presented control strategy was verified via simulation studies implemented in MATLAB/Simulink environment.