DC Power Quality in Grid-Connected Energy Hubs

The rapid growth of renewable energy generation and the increase in load significantly challenge the existing electrical infrastructure and cause network congestion in the Netherlands. Since building new networks takes a long time and also incurs a large investment, energy hubs emerge as a faster and more innovative alternative. In these systems, distributed energy resources, energy storage systems, non-linear loads, and power conversion devices are integrated to solve network congestion problem locally. However, it can also cause several power quality issues. This paper focuses on analyzing the power quality problems that originate on the DC side of the system. The study provides an overview of the energy hub architecture for high-power systems and introduces key definitions of power quality. The paper also discusses various disturbances in energy hubs, including their causes, consequences, and recommendations to minimize their impacts on the system. Furthermore, several standards are reviewed and used as the basis for defining power quality disturbances with respect to DC grids.