Dynamic analysis and modelling of a Francis hydro‐energy generation system in the load rejection transient

Li, Huanhuan; Chen, Diyi; Zhang, Xinguang; Wu, Yonghong

doi:10.1049/iet-rpg.2015.0579

Cited by 29 publications

(24 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…T T denotes the penstock elastic time constant, T T = L T /α ，L T is the penstock length. Equation (3) can be obtained by expanding (2) and omitting the high-order terms…”

Section: Dynamic Characteristics Of the Penstockmentioning

confidence: 99%

“…There is a certain degree of pressure pulsation which cannot be avoided in the draft tube during the operation of a hydropower station [1][2][3]. It can cause turbine output fluctuation, penstock hammer, unit vibration and so on, which brings challenges for the hydro-turbine governing system (HTGS) to regulate the transient characteristics of the hydropower system [4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic characteristics of a hydro‐turbine governing system considering draft tube pressure pulsation

Guo

Zhang

Gou

2020

IET Renewable Power Generation

View full text Add to dashboard Cite

Hydropower takes on many tasks such as peak regulation and frequency modulation in the power system. In the actual operation process of the hydro-turbine governing system, there is a certain degree of pressure pulsation in the draft tube. When the system is under unrated operating conditions, the draft tube pressure pulsation is more intense, and its dynamic behaviour becomes more complicated. In this study, the draft tube pressure pulsation is introduced into the dynamic model of the hydro-turbine governing system, and its influences on the transient characteristics of the system are analysed under unrated conditions and rated conditions. The authors find that compared with the rated conditions, the draft tube pressure pulsation under unrated conditions has more significant effects on the transient characteristics of the system. A damped frequency of pressure pulsation is proposed in this study which provides an efficient method of regulating the dynamic behaviour of the system in real operation. All these findings are expected to be helpful for further study of the influence of pressure pulsation on transient characteristics of hydropower systems and improving their dynamic characteristics under operating conditions.

show abstract

“…T T denotes the penstock elastic time constant, T T = L T /α ，L T is the penstock length. Equation (3) can be obtained by expanding (2) and omitting the high-order terms…”

Section: Dynamic Characteristics Of the Penstockmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dynamic characteristics of a hydro‐turbine governing system considering draft tube pressure pulsation

Guo

Zhang

Gou

2020

IET Renewable Power Generation

View full text Add to dashboard Cite

show abstract

“…The peak of the slope is directly proportional to the load imbalance and inversely proportional to its inertial constant [18]. The load rejection test is most widely conducted to evaluate the transient characteristic of any generator based power systems [19,20]. The experimentation performed in this paper is a vibrational characterisation of SG when loaded above rated loads (up to 120%) subjected to sudden load rejection.…”

Section: Descriptive Interpretations On Frequency Behaviour At Load Rmentioning

confidence: 99%

Simulation and experimental illustration of vibration at load rejection in a continuously overloaded large hydrogenerator

Carounagarane

Chelliah

Sarma³

2020

IET Renewable Power Generation

View full text Add to dashboard Cite

Large hydro generators are usually overloaded at various situations such as the period when excess water is available and when excess inflow is to be discharged. The period may have extended to many weeks under exigent conditions e.g. six weeks in case of a 1000 MW hydropower plant (HPP) located at northern region, India at 20% overload. All the performance related parameters including vibrations were observed during commissioning except runaway speed test at load rejection. At overloads, if there is a sudden load rejection the vibration transients will be even more severe due to drop in current and internal impedance. Hence this paper aims to analyze the vibration signature of large synchronous generator (SG) when operated at overloads and subjected to sudden load rejection. The substantiation of the factual model of 250 MW hydro generating units (HGU) replicating the case plant has been simulated using SIMSEN software. Apart from case report and simulative validation an experimental verification is also conducted with a prototype model of 2.2 kW SG. This paper provides the feasibility to operate the SG's 20% beyond its rated load as designed with proper maintenance and safety carried out by plant operators.

show abstract

“…The turbine governing system of a small hydropower station is a complex nonlinear coupling system which mainly undertakes power output modulation and frequency regulation. The start-up process of a small hydroelectric power plant is closely related to the turbine governing system, which is composed of a hydraulic-turbine governor, a hydro-turbine, a generator, and a conduit system (seen in Figure 1) [20,25,26]. In this section, the mathematical model of turbine regulation system is introduced.…”

Section: Mathematic Modelmentioning

confidence: 99%

Impact of Tail Water Fluctuation on Turbine Start-Up and Optimized Regulation

Chen

Wang

et al. 2019

Energies

View full text Add to dashboard Cite

Small hydropower plants are usually run-of-river with a poor adjustment capacity, and, therefore, large tail water fluctuation may be induced during flood discharge. Meanwhile, the turbine units need to be quickly started-up due to the regulation requirements of the power grid. However, failures of the start-up and grid connection are often encountered because of severe tail water fluctuation. In order to achieve the rapid and stable start-up under tail water fluctuations and to reduce the negative effect of start-up on turbine runner blades, the fluctuation law of the tail water from flood discharge model test is introduced as the boundary condition. A multi-objective comprehensive (MOC) index is proposed to optimize the parameters of the governor. Then the impacts of the tail water amplitude and frequency on the start-up are simulated and analyzed. Moreover, the start-up characteristics under the Integral Time Absolute Error (ITAE) index and the MOC index are compared through particle swarm optimization (PSO). The results show that both indices can ensure the rapidity of start-up under tail water fluctuation, whereas the MOC index can achieve a more stable start-up process. Therefore, the MOC index has a better stability and a less negative effect on the turbine runner blades.

show abstract

Dynamic analysis and modelling of a Francis hydro‐energy generation system in the load rejection transient

Cited by 29 publications

References 29 publications

Dynamic characteristics of a hydro‐turbine governing system considering draft tube pressure pulsation

Dynamic characteristics of a hydro‐turbine governing system considering draft tube pressure pulsation

Simulation and experimental illustration of vibration at load rejection in a continuously overloaded large hydrogenerator

Impact of Tail Water Fluctuation on Turbine Start-Up and Optimized Regulation

Contact Info

Product

Resources

About