DSP based implementation of an immune feedback algorithm for control of shunt compensator

This paper presents a three phase shunt compensator for addressing several power quality problems such as harmonics, reactive power and load unbalancing at distribution level. A configuration chosen for the DSTATCOM in the paper is based on a three-phase, three-leg converter which is suitably controlled as compensator for performing these functions. The algorithm developed for the control of voltage source converter (VSC) is based on immune feedback principle which is an adaptive system. The immune feedback controller estimates fundamental reference grid currents. This control algorithm proposed for DSTATCOM is validated for maintaining power factor to unity, load balancing and harmonics reduction. Experimental results are obtained with the proposed controller which is tested on the prototype model developed in the laboratory. It is observed from both the simulation and hardware results that proper control of DSTATCOM is able to achieve unity power factor operation at the grid end under load changes. Also, simulation results for voltage regulation have been presented using the proposed algorithm.