Modeling, control and simulation of grid-connected PV system with D-STATCOM

Due to the national subsidy policy and the demand of energy, photovoltaic power generation is growing at a rapid rate all over the world. When new PV installations connect to utility grid, some problems, such as reactive power compensation, voltage stability and power quality, are around the corner. This paper presents a grid-connected PV simulation system with D-STATCOM. By using Matlab/Simulink for modeling PV system, this paper shows I-V and P-V characteristics of PV array, and uses D-STATCOM as the grid-connected converter to realize power coordination, voltage stabilizing and power quality improvement. The basic control strategy is dual-close-loop control strategy. By decoupling active power and reactive power, inner loop control algorithm is used to trace active power and reactive power current separately. Meanwhile, outer loop regulates DC link voltage and grid-connected voltage. The simulation result shows that PV system with D-STATCOM can output active power stably, keep grid-connected voltage steady, and improve power quality of output voltage and current.