Enhanced ancillary services provision in Swedish hybrid power plants

Hjuleberg is the latest Vattenfall commercial hybrid power plant in Sweden, which went into operation in the summer of 2024. It comprises a 36 MW Wind Farm and a 30 MW Battery Energy Storage System (BESS), interconnected at the same point of connection to the grid. These are controlled as a single power plant through the use of the Hybrid Power Plant Controller (HPPC), a Vattenfall in-house developed software solution. The HPPC is able to support the stability of the grid through provision of a range of ancillary services in accordance with the requirements by the Swedish Transmission System Operator (TSO). In this article, it is shown how the hybrid park is operated as a single unit in order to maximize volumes of the ancillary services that can be delivered. In particular, it is shown that the HPPC facilitates the provision of Frequency Containment Reserves (FCR) under different loading conditions and meets time and frequency domain technical requirements related with the amount of power and energy delivered, response speed and robust stability. Furthermore, it is shown how the HPPC is compliant with the latest Limited Energy Reservoir (LER) endurance requirements for the Nordics. These developments make Hjuleberg one of the most advanced hybrid parks in Europe, showcasing how advanced software control solutions can contribute to enhance grid stability and minimize the curtailment of renewables power.