Solar PV Generation Based Microgrid Control Interfaced to Utility Grid

Abstract

The solar photovoltaic (PV) generation-based microgrid (MG) control interfaced to the utility grid is presented in this paper. The DC links for the voltage source converters (VSC), such as the main and ancillary VSCs are integrated to two solar PV arrays of different power rating with separate maximum power point tracking (MPPT) algorithm in cost-effective and effectual single stage topology. A point of common coupling (PCC), where VSC’s are linked through the parallel form with distinct nonlinear loads. The main VSC transfers active power toward utility grid and manages loads requirement connected across it. Whereas the ancillary VSC maintains its load demand in grid tied mode. The ancillary VSC sustains the load requirement in an off-grid mode, thus makes the MG more reliable. The current control approach is utilized by the main VSC in the grid integrated mode under normal situation. However, at the grid disturbance, it shifts towards voltage control in standalone mode and as a grid forming inverter. The power electronics switch makes seamless mode shifting operation for the main VSC’s grid interactive and standalone modes. At PCC, the main VSC’s voltage control sustains the frequency and voltage, so it provides a reliable and incessant power to the load network. The ancillary VSC always works with the current control approach. The feed-forward terms of solar PV powers of arrays are used in the current control technique of VSCs, to enhance the dynamic behaviour of system. The current control also enhances the power quality concerns like extenuation of harmonics current and power factor correction at the grid or at the grid forming converter. The microgrid’s satisfactory performance is perceived under steady state and dynamic conditions i.e. changing solar irradiance, load alteration, unbalance in load and is authenticated through the MATLAB/SIMULINK platform.