Enhancement of power quality and voltage flicker mitigation using new PWM based DSTATCOM

Abstract

Voltage sag, harmonic, transient, over voltage and under voltage are major voltage quality issues in a distribution system. The problem occurs due to the shortage or excess of reactive power transfer in the distribution system. A Static Compensator (STATCOM) is a flexible ac transmission system (FACTS) controller, which can either absorb or deliver reactive power to a power system. A Distribution Static Compensator (DSTATCOM) is proposed in this paper for compensation of reactive power and unbalance caused by various loads in distribution system. DSTATCOM is based on the VSC principle, injects current into the system to correct the voltage sag, swell and power factor. It is also an effective measure to maintain voltage stability and improve power quality of distribution grid. This paper proposes the dynamic performance of a DSTATCOM (intended to replace the widely used static VAR compensator) for mitigation of voltage flicker and power quality improvement (SVC). The simulation is carried out using MATLAB/SIMULINK on a 25kV distribution network connected to DSTATCOM. PSCAD simulation tool is also used for model implementation with new PWM based control scheme and results are compared with the prototype model of DSTATCOM. Results illustrate the performance of DSTATCOM in mitigation of voltage flicker caused by rapidly varying reactive current demand and improvement of power handling capability.