Stability Investigation for a 100 kW Solar Photovoltaic Grid-Connected System Using D-STATCOM Control

Abstract

This paper investigates the study of stability for a 100 kW solar photovoltaic (SPV) grid-connected system using distributed static compensator (D-STATCOM) control. The proposed D-STATCOM control works as compensating reactive power source, which decreases the voltage variation on the distribution side of the proposed system. In addition, an isolated DC–DC converter has been implemented in conjunction with three-phase DC–AC voltage source converter (VSC) in double-stage grid-connected system operating at unity power factor. Especially, an integral regulator (IR) type of incremental conductance (IC)–maximum power point tracking (MPPT) technique has been applied, which controls the output voltage of SPV array and derives the maximum power from SPV array under changing atmospheric circumstances. Furthermore, the proposed MPPT technique has been proven highly converging in tracking of maximum power and keeps a steady DC link supply by altering the index of the converter. For the duration of the faulted conditions at grid side, the resulting balanced waveforms at point of common coupling (PCC) have been obtained. Additionally, harmonic study carried demonstrates the role of D-STATCOM in the reduction of harmonics and DC offset at utility side providing a stable steady state and transient response. In order to authorize the proposed system, the MATLAB simulations have been performed to show the usefulness of D-STATCOM control in proposed double-stage SPV grid-connected system.