Frequency Stability of Isolated Hydropower Plant with Surge Tank Under Different Turbine Control Modes
2015 (English)In: Electric power components and systems, ISSN 1532-5008, E-ISSN 1532-5016, Vol. 43, no 15, 1707-1716 p.Article in journal (Refereed) Published
Currently, the Thoma criterion is often violated to diminish the cross-section of the surge tank; therefore, the surge fluctuation is aggravated and the frequency stability becomes more deteriorative. The focus of this article is on stabilizing the low-frequency oscillation of an isolated hydropower plant caused by surge fluctuation. From a new perspective of hydropower plant operation mode, frequency stability under power control is investigated and compared with frequency control by adopting the Hurwitz criterion and numerical simulation. In a theoretical derivation, the governor equations of frequency control and power control are introduced to the mathematical model. For numerical simulation, a governor model with a control mode switch-over function is built. The frequency oscillations under frequency control, power control, and control mode switch-over are simulated and investigated, respectively, with different governor parameters and operation cases. The result shows that the power control has a better performance on frequency stability at the expense of rapidity compared with the frequency control. Other recommendations regarding worst operation cases and choice of control modes are also developed.
Place, publisher, year, edition, pages
2015. Vol. 43, no 15, 1707-1716 p.
Other Engineering and Technologies
IdentifiersURN: urn:nbn:se:uu:diva-260774DOI: 10.1080/15325008.2015.1049722ISI: 000359869100003OAI: oai:DiVA.org:uu-260774DiVA: diva2:848389