Implementation of Immune Feedback Control Algorithm for Distribution Static Compensator

Abstract

This paper presents an immune feedback control algorithm for a three-phase distribution static compensator (DSTATCOM) to mitigate several power quality problems such as harmonics, reactive power, and load unbalancing at distribution level. A configuration chosen for DSTATCOM is based on a three-phase voltage source converter (VSC), which is suitably controlled as a shunt compensator for performing these functions. The underlying principle of an immune feedback is based on adaptive control and the designed control estimates fundamental reference grid currents from nonlinear load currents. This control algorithm proposed for DSTATCOM, is validated for maintaining power factor to unity, load balancing, and harmonics reduction of supply currents. An improved performance of immune feedback control is presented along with its comparison with conventional control algorithms such as dq frame, normalized least mean square and other recently developed control algorithms such as leaky least mean square, leaky least mean fourth, and synchronous extraction. Experimental results are obtained with the proposed control, which is tested on a prototype developed in the laboratory using a VSC. It is observed from simulation and experimental results that the proposed control algorithm of DSTATCOM is able to achieve mitigation of most of the power quality problems at the distribution level.