Dynamisk koppling av vattenkraftsaggregat och stationer för frekvensreglering : Modellering och utvärdering av tillhandahållande av FCR tjänster från system med flera aggregat i gemensam älvfåra

This study investigates the feasibility of providing Frequency Containment Reserves (FCR) using Run-of-River hydropower units along a common river section. These units, characterized by limited storage capacities, are hydrologically coupled, by the water flowing between them, indirectly impacting each other’s power response through varying hydraulic heads. To address this, a case study of four hydropower plants owned by the energy company Fortum was modeled in the software MATLAB and Simulink to simulate the dynamic response when applying frequency signals. The units of the case study are equipped with Kaplan turbines and this in combination with relatively low hydraulic heads and a high discharge capacity implies slow dynamics. To evaluate the unit’s chances to provide FCR, the latest version of the prequalification requirements for FCR-N and FCR-D are applied to the model of each unit as well as an aggregated group of units. The test results revealed that all FCR-N requirements were met while some FCR-D requirements failed due to stringent requirements of fast regulation. Additionally, the study analyzed the impact on water levels between the power plants while providing frequency regulation and the effect of implementing water level regulation on some units to keep the water levels within certain boundaries. Results indicated that water level regulation significantly affected the power response, contradicting the purpose of frequency regulation. Moreover, water levels were more stable when providing FCR from all four hydropower plants simultaneously.