Power quality improvement using DSTATCOM with affine projection algorithm

Abstract

A distribution static compensator (DSTATCOM) is implemented at distribution level for overcoming several power quality problems commonly encountered today. Some of these problems considered here deal with issues of harmonics, unbalancing of loads, meeting reactive power demand of the load for improving power factor to unity and regulating the voltage. A new technique is proposed based on affine projection control algorithm and its design and implementation on a shunt compensator are discussed. The proposed control approach estimates the fundamental weight values of load currents. These weights are utilised to compute the magnitude and phase of reference grid currents and consequently gating pulses for three-phase voltage source converter (VSC). The control approach is based on the convergence of the weighted values and is independent of the property of the input signal. This control approach has characteristic of updating weights on the basis of multiple, delayed input signal vectors. Fast convergence of active and reactive weighted values is added advantage of the proposed control approach with the above-mentioned characteristics. A working prototype of the DSTATCOM is implemented using three-phase VSC and digital signal processor (DSP) (dSPACE 1104). The affine projection control approach is developed in MATLAB/SIMULINK and verified on a prototype using DSP.