Stability Analysis of a Run-of-River Diversion Hydropower Plant with Surge Tank and Spillway in the Head Pond

Abstract

Run-of-river hydropower plants usually lack significant storage capacity; therefore, the more adequate control strategy would consist of keeping a constant water level at the intake pond in order to harness the maximum amount of energy from the river flow or to reduce the surface flooded in the head pond. In this paper, a standard PI control system of a run-of-river diversion hydropower plant with surge tank and a spillway in the head pond that evacuates part of the river flow plant is studied. A stability analysis based on the Routh-Hurwitz criterion is carried out and a practical criterion for tuning the gains of the PI controller is proposed. Conclusions about the head pond and surge tank areas are drawn from the stability analysis. Finally, this criterion is applied to a real hydropower plant in design state; the importance of considering the spillway dimensions and turbine characteristic curves for adequate tuning of the controller gains is highlighted.

On the Implementation of Variable Speed in Pump-Turbine Units Providing Primary and Secondary Load-Frequency Control in Generating Mode

“…In this paper, a lumped parameters model has been used to transform the above-mentioned system of partial differential equations in a system of ordinary differential equations [13,16]. For the long penstock configuration, the penstock has been modelled through Equations (1) and (2), considering ten Γ-shaped consecutive elements (n ge = 10), Figure 2 [7,17].…”

“…Energies 2015, 88, page-page configuration, the penstock has been modelled through Equations (1) and (2), considering ten Г-shaped consecutive elements (nge = 10), Figure 2 [7,17]. Table 1.…”

“…Expression in Equation (4) includes a correction coefficient β to match the first peak of the frequency response of the continuous model [18]. configuration, the penstock has been modelled through Equations (1) and (2), considering ten Г-shaped consecutive elements (nge = 10), Figure 2 [7,17]. Table 1.…”

“…The performance curves of the pump-turbine unit in generating mode have been approximated by those used in [17] and are shown in Figure 4. In this case the hill chart, expressed as a function of the unit speed n 11 and flow q 11 in Equation (5), is experimental, where z is the wicket gates position.…”

Frequency control of hybrid wind-hydro power plants with long conduits in isolated power systems

“…In order to evaluate the plant's response, different cases regarding initial river flow were considered, to simulate them in the non-linear model. This methodology has also been followed successfully in (Sarasúa, et al, 2014), where the authors study the stability of the water level control system of a run-of-river hydropower plant under normal operating conditions, using a small perturbation analysis. In this case, the results obtained in this study have been applied to the Ocaña II hydro plant (Cuenca, Ecuador) which is currently in its design phase.…”