Impacts of the 2012–2015 Drought on the Brazilian Hydropower System

The short-term joint optimal operation simulation of Three Gorges cascade hydropower system aiming at maximum power generation benefit is proposed. And a new method for optimizing cascade hydropower station based on Adaptive Genetic Algorithm (AGA) with trigonometric selective operators is presented. In this paper, the practical optimal operation in power market is described. The temporal-spatial variation of flow between cascade hydropower stations is considered, and time of use (TOU) power price is also taken into account. Moreover, a contrast between Tangent-roulette selection operator and traditional one is made. To a certain degree, the results of simulative optimal operation based on several representative hydrographs show that Tangent-roulette wheel selection operator can find a more excellent solution, because the Tangent-roulette one can overcome the fitness requirements of non-negative. The research achievements also have an important reference for the compilation of daily generation scheduling of Three Gorges cascade hydropower system in the environment of power market.

Download Full-text

Analysis of a Stochastic Programming Model for Optimal Hydropower System Operation under a Deregulated Electricity Market by Considering Forecasting Uncertainty

Water ◽

10.3390/w10070885 ◽

2018 ◽

Vol 10 (7) ◽

pp. 885 ◽

Cited By ~ 4

Author(s):

Bin Xu ◽

Ping-An Zhong ◽

Baoyi Du ◽

Juan Chen ◽

Weifeng Liu ◽

...

Keyword(s):

Stochastic Programming ◽

Electricity Market ◽

Energy Production ◽

Programming Model ◽

Optimal Operation ◽

Spot Price ◽

Deregulated Electricity Market ◽

Hydropower System ◽

Stochastic Programming Model ◽

Hydropower Operation

In a deregulated electricity market, optimal hydropower operation should be achieved through informed decisions to facilitate the delivery of energy production in forward markets and energy purchase level from other power producers within real-time markets. This study develops a stochastic programming model that considers the influence of uncertain streamflow on hydropower energy production and the effect of variable spot energy prices on the cost of energy purchase (energy shortfall). The proposed model is able to handle uncertainties expressed by both a probability distribution and discretized scenarios. Conflicting decisions are resolved by maximizing the expected value of net revenue, which jointly considers benefit and cost terms under uncertainty. Methodologies are verified using a case study of the Three Gorges cascade hydropower system. The results demonstrate that optimal operation policies are derived based upon systematic evaluations on the benefit and cost terms that are affected by multiple uncertainties. Moreover, near-optimal operation policy under the case of inaccurate spot price forecasts is also analyzed. The results also show that a proper policy for guiding hydropower operation seeks the best compromise between energy production and energy purchase levels, which explores their nonlinear tradeoffs over different time periods.

Download Full-text

Load frequency control for mini-hydropower system: A new approach based on self-tuning fuzzy proportional-derivative scheme

Sustainable Energy Technologies and Assessments ◽

10.1016/j.seta.2018.10.013 ◽

2018 ◽

Vol 30 ◽

pp. 253-262 ◽

Cited By ~ 2

Author(s):

M. Reyasudin Basir Khan ◽

Jagadeesh Pasupuleti ◽

Razali Jidin

Keyword(s):

Frequency Control ◽

Load Frequency Control ◽

New Approach ◽

Load Frequency ◽

System A ◽

Hydropower System ◽

Self Tuning

Download Full-text

Optimization of Year-End Water Level of Multi-Year Regulating Reservoir in Cascade Hydropower System Considering the Inflow Frequency Difference

Energies ◽

10.3390/en13205345 ◽

2020 ◽

Vol 13 (20) ◽

pp. 5345

Author(s):

Zhiqiang Jiang ◽

Peibing Song ◽

Xiang Liao

Keyword(s):

Power Generation ◽

Dynamic Programming ◽

Water Level ◽

Water Levels ◽

Least Square ◽

Frequency Difference ◽

Impact Factors ◽

Cascade System ◽

Cascade Reservoirs ◽

Hydropower System

In order to analyze the year-end water level of multi-year regulating reservoir of the cascade hydropower system, this paper studied the joint operation optimization model of cascade reservoirs and its solving method based on multi-dimensional dynamic programming, and analyzed the power generation impact factors of cascade system that contains multi-year regulating reservoir. In particular, taking the seven reservoirs in the middle and lower reaches of Yalong River as an example, the optimal year-end water levels of multi-year regulating reservoir under the multi-year average situation and different inflow frequencies situation were studied. Based on the optimal calculation results of multi-dimensional dynamic programming, the inflow frequency difference considered operation rule of year-end water level of Lianghekou reservoir was extracted using the least square principle. The simulation results showed that, compared with the fixed year-end water level in multi-year, the extracted rule can improve the cascade power generation by more than 400 million kWh in an average year, representing an increase of 0.4%. This result means that the extracted rule can give full play to the regulation performance of multi-year regulating reservoir and improve the conversion efficiency of hydropower resources in cascade system. This is of great significance to the practical operation of cascade reservoirs system that contains multi-year regulating reservoir.

Download Full-text