Study On Characteristic And Application Of Storage Spatial Distribution For Multi-reservoir System

With the increasing of water use due to economic and social development,the unbalanced distribution of water resources is becoming more and more significantly. Thus, the challenges for water resources management on theories and techniques are proposed. One of them is the joint operation problem of multi-reservoir system such as inter-basin water transfer-supply project, reservoirs system for water supply and cascade reservoirs group for energy production. For the past decades, the optimal operation for multi-reservoir system has been widely studied. However, many difficulties still need to be conquered on both the internal distribution characteristics of storages and effective operation rules for reservoir systems of different features, including theoretical investigation and establishment of optimization model.Focusing on the characteristics of storage spatial distribution and operation rules based on it, the research progress on the theories and methods of reservoir operation is reviewed. By taking the parallel multi-reservoir system for water supply in Liaoning province and the cascade reservoirs in Huangbaihe river basin as examples, theoretical study on regularity of spatial distribution of system storage is proposed. The methods and techniques of sloving muti-reservoir scheduling model are approached in the aspects of developing efficient operation rules and building optimazation models.Firstly, with the discussion on the form and physical significance of spatial distribution of storage in multi-reservoirs, as such the water supply system of two parallel reservoir, storage allocation rules in drawdown and refill season are derived and concepts of reservoir regulation index and threshold storage value of compensation adjustment are proposed based on space rule. Then, storage allocation rule based on balancing curves is proposed for water supply reservoirs in parallel. The simulation and optimization model based on the characteristics of storage spatial distribution is established and solved by the improved particle swarm algorithm, applied to the parallel system in Liaoning province. The results illustrate the construction of the reservoir space distribution of joint scheduling rules and validity and rationality of optimization model. Consistent with the theoretical analysis, the results also verifis that the spatial distribution of system storages has characteristic of threshold value and that either reservoir is not always a compensating one. The applicability of the proposed rules with different hydrological conditions is further discussed. Thirdly, based on the analysis of some shortcomings of discriminant criterion method, storage allocation rule based on balancing curves expands to the application of cascade reservoirs operation. The modified joint operating rules include the system-wide release rule that specifies what to release from the system and the balancing curves that identify the desired storage in each reservoirs, all as functions of total storage of system and time of year using the pattern of piecewise linear. An optimization model based on water allocation is set up with the goal of maximizing total generating capacity deriving the long-term operation for the cascade reservoirs in Huangbaihe river basin. The operation results of the power generation and the reliability both have a certain degree of ascension compare with the conventional dispatching scheme, which provides a new idea for optimal operation of cascade reservoirs. And the finally, with the discussion on the limitations of space rule, energy space rule is obtained and a one-period optimization model based on target energy storage is established. In order to improve the model, the target energy storage parameter value is derived under the objective function of energy maximization. Two hypothetical reservoirs in parallel to satisfy a joint energy requirement is applied to verify the effectiveness of the model. The differences of comparison on performance among combining schemes are also figured out that the preferred choice of energy space rule in refill season and derived energy target in drawdown season. Further investigation of energy distribution regulation is processing.This dissertation developed the reservoirs operation theory about storage spatial distribution, defined the concepts of reservoir regulation index and threshold storage value of compensation adjustment, proposed the joint operation rules based on balancing curves, constructed optimation models of reservoirs in parallel and in series for both water supply and energy production, discussed the sensibility of the proposed rule under different hydrological conditions and the limitations of space rule, improved the one-period optimization model based on target energy storage. The work has a positive meaning in advancing theory analysis of optimal operation of system storage allocation and joint operation rule of simulation-optimazation model.