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With the growth in the share of variable renewable energy sources, fluctuations in the power generation caused by these types of power plants can diminish the stability and flexibility of the grid. These two can be enhanced by applying frequency containment using hydropower plants as an operational reserve. The frequency containment in hydropower plants is automatically controlled by speed governors within seconds. Disturbances such as fluctuations in the net head and aging may diminish the performance of the controllers of the speed governors. In this study, model reference adaptive control approaches based on the Massachusetts Institute of Technology (MIT) rule and Lyapunov method were exploited in order to improve the performance of the speed governor for frequency containment control. The active power control with frequency control was enhanced by the aforementioned adaptive control methods. A mathematical model of a hydropower plant with a surge tank and medium penstock was constructed and validated through site measurements of a plant. It was shown that, as they are applicable in real life, both methods perform significantly better compared to conventional proportional-integrator control. Even in first five deviations, the performance of the conventional controller improved by 58.8% using the MIT rule and by 65.9% using the Lyapunov method. When the two adaptive control approaches were compared with each other, the MIT rule outputted better results than the Lyapunov method when the disturbance frequency was higher; however, the latter was more functional for rare disturbances.
Doğan Gezer; Yiğit Taşcıoğlu; Kutay Çelebioğlu. Frequency Containment Control of Hydropower Plants Using Different Adaptive Methods. Energies 2021, 14, 2082 .
AMA StyleDoğan Gezer, Yiğit Taşcıoğlu, Kutay Çelebioğlu. Frequency Containment Control of Hydropower Plants Using Different Adaptive Methods. Energies. 2021; 14 (8):2082.
Chicago/Turabian StyleDoğan Gezer; Yiğit Taşcıoğlu; Kutay Çelebioğlu. 2021. "Frequency Containment Control of Hydropower Plants Using Different Adaptive Methods." Energies 14, no. 8: 2082.
Background: Parameters of the hydroelectric power plant controllers are typically tuned at the nominal operating conditions such as nominal head and single unit operation. Water level variations in reservoir and/or tailwater, and the presence of other active units sharing the penstock are common disturbances to the nominal assumption. Methods: This article proposes two adaptive add-ons, namely gain scheduling and model reference adaptive control, to the existing speed controllers to improve grid synchronization performance when the site conditions are not nominal. The add-ons were designed and tested on a validated dynamic model of a power plant unit by using a software-in-the-loop simulation setup. An off-season scenario is simulated, in which the original controller of the unit cannot bring the turbine to synchronize with the grid due to low gross head. Then, the add-ons were implemented on-site and experiments were performed under similar conditions. The parameter sets used in gain scheduling for different operation bands are determined off-line with the help of operational experience. The model reference adaptive control add-on requires a reference model and a learning rate. A description of the turbine speed-up profile at nominal operating conditions is sufficient to be used as the reference model. The proposed piecewise linear reference model favors stability over speed in settling to the nominal speed. Results: It is experimentally shown that the proposed add-ons compensate the negative effect of head loss in grid synchronization, and perform similar to the ideal performance at the nominal head. Conclusion: Both add-ons can be implemented on the available off-the-shelf speed governor controllers. They are suitable for use in all hydroelectric power plants, especially in unmanned ones, for automatic synchronization with less waste water.
Dogan Gezer; Yigit Tascioglu; Kutay Çelebioğlu. Speed control of hydraulic turbines for grid synchronization using simple adaptive add-ons. Measurement and Control 2018, 51, 276 -284.
AMA StyleDogan Gezer, Yigit Tascioglu, Kutay Çelebioğlu. Speed control of hydraulic turbines for grid synchronization using simple adaptive add-ons. Measurement and Control. 2018; 51 (7-8):276-284.
Chicago/Turabian StyleDogan Gezer; Yigit Tascioglu; Kutay Çelebioğlu. 2018. "Speed control of hydraulic turbines for grid synchronization using simple adaptive add-ons." Measurement and Control 51, no. 7-8: 276-284.
This paper presents a method to design and enhance the performance of speed governors for aged Hydroelectric Power Plants (HEPP) utilizing limited number of online site tests. First, the mathematical model for the governor is generated using plant parameters. Afterwards, the aging and backlash effects are added to the model in order to match the simulation outputs with the site measurements. The feed forward and Ziegler–Nichols (ZN) methods are examined in order to mitigate the impact of backlash. Between these methods the former one is selected since it also provides island-mode stability. The updated speed governor is applied to Gezende HEPP governor and performance progress is observed.
Abdullah Altay; Cem Sahin; Ires Iskender; Doğan Gezer; Caner Cakir; Caner Çakır. A compensator design for the aged hydro electric power plant speed governors. Electric Power Systems Research 2016, 133, 257 -268.
AMA StyleAbdullah Altay, Cem Sahin, Ires Iskender, Doğan Gezer, Caner Cakir, Caner Çakır. A compensator design for the aged hydro electric power plant speed governors. Electric Power Systems Research. 2016; 133 ():257-268.
Chicago/Turabian StyleAbdullah Altay; Cem Sahin; Ires Iskender; Doğan Gezer; Caner Cakir; Caner Çakır. 2016. "A compensator design for the aged hydro electric power plant speed governors." Electric Power Systems Research 133, no. : 257-268.