说明：  This paper presents the modeling and implementation of a three-phase DSTATCOM (Distribution Static Compensator) using STF (Self Tuning Filter) based IRPT (Instantaneous Reactive Power Theory) control algorithm for power quality improvement. It is used for harmonics elimination, load balancing and reactive power compensation at distorted PCC (Point of Common Coupling) voltages under nonlinear loads. An adaptive fuzzy logic controller is used to control the dc bus voltage of VSC (Voltage Source Converter) based DSTATCOM to improve the response and to reduce the overshoot and undershoot of traditiona