A Novel State of Charge based Energy Management for Solar PV-Battery Micro-grid.

The battery energy storage (BES) plays multiple roles including load leveling, emergency power supply and smoothing, enhancement of stability, and power quality of renewable based micro-grid. A proper control and energy management is an important part of a solar PV-battery integrated micro-grid. This paper presents a battery state of charge (SoC) based energy management and control technique for a grid-tied solar PV-battery based micro-grid. In this study, a laboratory-scale micro-grid is developed in the laboratory which consists of solar PV (solar array emulator), Li-ion batteries, a DC/DC boost converter, a bidirectional DC/DC converter, a three-phase PWM inverter, and a variable AC power supply that serves as the grid. Different controllers, such as DC/DC boost converter control, bi-directional DC/DC converter control, and vector control for inverter, are designed and implemented in the MATLAB/Simulink environment. The proposed energy management algorithm and real-time battery SoC estimation technique are also implemented in the MATLAB/Simulink environment. The control desk for the micro-grid is developed in a dSPACE unit, where the MATLAB/Simulink code runs in real-time and it is the interface between the hardware in the micro-grid and control desk. Multiple case studies are conducted in the laboratory to validate the accuracy and effectiveness of the proposed energy management and control technique.