Three Phase Four Wire Paralleled Inverters Control of MG with SPVs and Battery for Industrial Buildings

Abstract

In this work, the control for three phase four wire paralleled inverters based microgrid (MG) with solar photovoltaic (SPV) arrays and battery is presented for the buildings. The first PV array is connected via a DC-DC boost converter across the main voltage source converter (VSC) DC link, where a battery is also integrated. The second PV array is integrated directly at ancillary VSC DC link in a structure of single stage. The distinctive maximum power point tracking (MPPT) techniques are utilized for both PV arrays. The main VSC's works via a current control technique in grid intertie operative state. At the grid outage, it transfers to the voltage control and continuous power is delivered to loads. The VSCs terminals are integrated at the point of common coupling (PCC), wherein loads are also integrated. The voltage control regulates PCC frequency and voltage, so, ancillary inverter operates always by the current control. In the VSCs current controls, the utilization of PV array's power for feed-forward term enhances the dynamic performance. MG compensates the neutral current and improves power quality concerns. The microgrid behaviour is analysed under the environment of RT-LAB through OPAL-RT i.e. digital simulator (OP4510) and its performance is satisfactory under dynamic situations such as, load unbalance, SPV power perturbation, grid outage and grid reconnection.