A Dual Fundamental Current Extraction Controller for DSTATCOM in the Distribution System for Power Quality Improvement Under Non-Ideal Source Voltage Condition

Abstract

Most of the controllers often fail to work properly when encountered with power quality (PQ) issues like unbalanced and distorted grid voltage conditions in three-phase distribution system (TPDS). To address this problem, usually a dynamic static compensator (DSTATCOM) is utilized in TPDS. For enhanced performance, a novel dual fundamental component extraction (DFCE) technique is proposed for generating reference currents (RC) in a TPDS exhausting DSTATCOM. The proposed controller is highly effective for reactive power compensation and source current harmonic suppression under source unbalanced voltages condition with nonlinear load conditions. For computation of RC and phase synchronization, the controller extracts the required fundamental voltage and current at the same time. Consequently, the controller is able to control DSTATCOM operation in TPDS without any phase locked loop (PLL) and low pass filter (LPF). For generation of fundamental components of voltage and current, projected controller utilizes the self-tuning filter (STF). The efficacy of the controller is established in comparison to existing controllers like synchronous reference frame theory, p-q theory and STF-p-q under different grid voltage conditions. To enhance PQ, the suggested controller works efficiently for fundamental current component extraction without using PLL and low/high pass filter in case of grid distorted voltage condition.