Supervisory Control System for a Grid-Connected MVDC Microgrid Based on Z-Source Converters With PV, Battery Storage, Green Hydrogen System and Charging Station of Electric Vehicles

Abstract

This paper presents a new supervisory control system (SCS) designed to maintain the power balance and obtain economic benefit by selling energy to the grid in a microgrid based on Z-source converters (ZSCs) with renewable energy, energy storage systems (ESSs), and charging station for electric vehicles (EV) connected to a medium voltage direct current (MVDC) link. The main components of the microgrid are a photovoltaic (PV) system, battery (BAT) and green hydrogen system with a fuel cell (FC), electrolyzer (LZ) and hydrogen tank as ESSs, a local grid connection and two units of fast chargers for EVs. Owing to the proposed configuration, the output voltages of the components can be adapted to the MVDC to control their output power and reduce the number of power converters compared to the common configuration without ZSCs. Thus, the configuration by itself and the SCS can be considered the main novelties of this paper. The simulation results and the hardware-in-the-loop tests show that the proposed system (ZSC-based configuration and SCS) is perfectly valid for the microgrid, and confirm the proper operation of the SCS to achieve an economic benefit from the use of the grid.