Modelling, Control and Simulation of a Microgrid based on PV System, Battery System and VSC

Nowadays, where the renewable energies are the new trend and sustainable technologies are starting to play a big role in the society in order to eliminate the dependence on fossil fuels, finding the way to collect these clean energies and to convert them into electricity at their highest performance is without any doubt essential. Nevertheless, the way to link the power generated from these renewable sources to the main grid is as well significant. The present project studies step by step the design, modelling, control and simulation of a microgrid based on several elements with a special focus to the Photovoltaic (PV) System and to the Voltage Source Converters (VSC). Modelling of the equivalent electric circuit model to simulate the working principle of a PV cell is studied in detail and a Maximum Power Point Tracking (MPPT) control algorithm to force the PV system works at its highest operation point is applied. A complete review of the two level VSC simplified model is elaborated and implemented to connect two DC sources (PV system and Battery system) to the main AC three-phase grid. Additionally, examples using the two level VSC real model based on six Insulated Gate Bipolar Transistors (IGBT) are tested, where the voltages modulation are obtained by applying Sinusoidal Pulse Width Modulation (SPWM). The control methodology for the several elements of the microgrid, most of them based on Proportional – Integral (PI) controllers to reduce the steady-state error to zero, ensures that a change in an input parameter of the system alters other components in order to reach a new balanced state in a small amount of time. The operation and behaviour of the entire microgrid is checked using software MATLAB Simulink and the results show a proper performance