Modelling and Control of a Grid-Connected RES-Hydrogen Hybrid Microgrid

Abstract

This paper proposes a Hybrid Microgrid (HμG) model including distributed generation (DG) and a hydrogen-based storage system, controlled through a tailored control strategy. The HμG is composed of three DG units, two of them supplied by solar and wind sources, and the latter one based on the exploitation of theProton Exchange Membrane (PEM) technology. Furthermore, the system includes an alkaline electrolyser, which is used as a responsive load to balance the excess of Variable Renewable Energy Sources (VRES) production, and to produce the hydrogen that will be stored into the hydrogen tank and that will be used to supply the fuel cell in case of lack of generation. The main objectives of this work are to present a validated dynamic model for every component of the HμG and to provide a strategy to reduce as much as possible the power absorption from the grid by exploiting the VRES production. The alkaline electrolyser and PEM fuel cell models are validated through real measurements. The State of Charge (SoC) of the hydrogen tank is adjusted through an adaptive scheme. Furthermore, the designed supervisor power control allows reducing the power exchange and improving the system stability. Finally, a case, considering a summer load profile measured in an electrical substation of Politecnico di Torino, is presented. The results demonstrates the advantages of a hydrogen-based micro-grid, where the hydrogen is used as medium to store the energy produced by photovoltaic and wind systems, with the aim to improve the self-sufficiency of the system.

Review of Power Control Methods for a Variable Average Power Load Model Designed for a Microgrid with Non-Controllable Renewable Energy Sources

“…Microgrid systems usually have a storage system to maintain the power balance in the system, and there are various types of storage, such as hydrogen [31][32][33], batteries [34][35][36][37], supercapacitors [38], electrochemical [39,40], and other types of storage [41]. The main purpose of any storage type in a microgrid system is to accumulate excess power when demand is lower than supply and use it at times when demand is greater than supply.…”

Coordinated Control of Proton Exchange Membrane Electrolyzers and Alkaline Electrolyzers for a Wind-to-Hydrogen Islanded Microgrid

“…Many mature control methods are used in hydrogen production systems. In [28], the strategy based on state machine control (SMC) is proposed to achieve coordinated control of the renewable-based hydrogen production systems, which is both simple and reliable. The MPC proposed in [29] effectively handles uncertainties and constraints in the hydrogen production systems.…”