Control of Three-Phase Four Wire Grid Integrated Multiple Solar PV Arrays-Battery with Bidirectional Converter Based Microgrid

Abstract

This paper presents a three-phase four wire grid interactive multiple solar photovoltaic (PV) and a battery based microgrid system. The DC links for the main voltage source converter (VSC) and the ancillary VSC are interfaced individually, to two solar PV arrays using a different maximum power point (MPP) tracking control i.e. incremental conductance (InC) method, in an inexpensive and effectual single stage topology. These VSCs are interfaced in parallel linkage to the point of common coupling (PCC) with distinct nonlinear loads, to enhance microgrid rating for distributing the active power on grid side and the system is reliable in an islanded mode. In normal situations, the current control is used for the main VSC in the grid intertied mode and at the disconnection from the grid, this system operates with the voltage control. The main VSC's mode transition performance is free from transitory and is obtained by a power electronic switch (PES). At the main VSC DC link, a DC-DC converter with the buck-boost operation is linked in series with the battery, manages the load network demand and sustains the DC link's voltage to MPP. At the PCC, frequency and voltage are regulated via voltage control and gives incessant power to the loads and good quality voltage is provided to the ancillary VSC to perform through the current control. The current control is utilized for power factor correction, harmonics eradication and enhancement of system's dynamics with PV feed-forward part. The microgrid operation is found satisfactory for scenarios like, grid outage, solar irradiance alteration, load unbalance and neutral current compensation and authenticated through simulated results obtained in MATLAB / SIMULINK platform.