Grid-supporting Battery Energy Storage Systems in the Low-voltage Distribution Grid

The integration of renewable energy sources into the distribution grid may cause more profound voltage deviations and overloading of grid elements. In certain countries (for example, Belgium), a lot of photovoltaic systems are connected to the low-voltage distribution grid at household residences. These renewable energy sources may cause excessive voltage increase at times when also the load is low (for example, during a weekday in summer). If the voltage increases above a certain limit, the photovoltaic systems are forced to stop injecting the energy into the grid. Battery energy storage systems can be installed to solve such a problem. Furthermore, battery energy storage systems can be applied for other goals throughout the grid; for example, electricity cost optimization and peak shaving at the household, feeder, or transformer level. Control systems for providing such services are developed in a multilayered approach: from real-time control of the semiconductor components switching to the long-term optimization in grid planning.