The Balance of Renewable Sources and User Demands in Grids: Power Electronics for Modular Battery Energy Storage Systems

TLDR

The rapid growth of renewable generation, which is inherently intermittent, threatens grid stability and can lead to costly outages of large offshore wind farms, making storage integration a critical solution. This paper examines two representative battery storage systems and the power electronics needed to integrate them into the grid. It presents grid‑integration strategies and optimal use of volatile reserves for a 5‑kW residential PV system and a 100‑MW wind‑farm medium‑voltage system, evaluating topology efficiency and cost as key factors for large‑scale renewable integration.

Abstract

The continuously growing amount of renewable sources starts compromising the stability of electrical grids. Contradictory to fossil fuel power plants, energy production of wind and photovoltaic (PV) energy is fluctuating. Although predictions have significantly improved, an outage of multi-MW offshore wind farms poses a challenging problem. One solution could be the integration of storage systems in the grid. After a short overview, this paper focuses on two exemplary battery storage systems, including the required power electronics. The grid integration, as well as the optimal usage of volatile energy reserves, is presented for a 5- kW PV system for home application, as well as for a 100- MW medium-voltage system, intended for wind farm usage. The efficiency and cost of topologies are investigated as a key parameter for large-scale integration of renewable power at medium- and low-voltage.