Fig. 2
From: Burden on hydropower units for short-term balancing of renewable power systems
Illustration of the simulation structure. The models 1–3 are introduced in Methods and Supplementary Note 3. The blocks with dashed outline represent the selections in simulation setting based on different conditions: i varies from 1–3, for three sets of governor parameters Ep1–Ep3; j varies from 1 to 4, for three regulation strategies (S1–S3) and an ideal on-cam case (S0); k varies from 1 to 2 for two HPPs; n varies from 1 to 7 for seven operating set-points. The set in the parenthesis with simulation presents different cases conducted in the model. In total, there are 168 (3 × 4 × 2 × 7) and 24 (3 × 4 × 2 × 1) simulation cases conducted in Model 1 and Model 2, respectively. The products in the parenthesis with the output variables show the actual needed set of results for analyzing the corresponding indicator in this paper
