Low Voltage Direct Current microgrids architectures for local energy community with PV/BESS systems : impact on energy efficiency

Abstract

This thesis investigates the potential benefits of integrating Low Voltage Direct Current (LVDC) microgrids into local energy communities (LECs) to reduce energy conversion losses. LVDC mi- crogrids have garnered attention due to their advantages over traditional Low Voltage Alternat- ing Current (LVAC) systems, which include fewer conversion stages, simpler control structures, and improved overall energy efficiency. As the global energy transition accelerates, driven by the urgent need to reduce carbon emissions, renewable energy sources (RES) like photovoltaics (PV) and energy storage systems (ESS) play a key role in transforming electricity distribution. These technologies are naturally DC-based, making LVDC grids an attractive option for local energy management, especially with the rising adoption of electric vehicles (EVs). The study simulates various microgrid topologies where PV panels, EVs, and battery energy storage systems (BESS) are either managed individually or communally. Using real data for PV production, EV consumption, and converter efficiency models, the simulations evaluate the en- ergy performance of different DC and AC microgrid configurations. Results suggest that direct DC connections between energy assets in LVDC architectures can significantly reduce energy losses compared to conventional AC-based microgrids, which require multiple conversion steps. A second set of simulations introduces real-world EV consumption data to assess the system’s performance under more dynamic and varied conditions. This analysis reveals that LVDC microgrids still offer notable advantages, particularly in configurations with shared energy assets and direct DC connections. The adoption of these innovative architectures resulted in 25.02% and 20.05% energy savings, respectively, compared to the classical AC-based architecture. This corresponds to 1755 kWh and 1405 kWh savings annually. These findings demonstrate that LVDC microgrids, particularly those with communal energy sharing, can significantly improve energy efficiency in local energy systems, even when faced with the variability of real-world consumption patterns.