Study On Reference Line Of Reservoir Operation Based On Stochastic Runoff Scenario

With the continuous deepening of our country’s industrial restructuring,as of 2020,our country’s total installed hydropower capacity will reach 380 million kilowatts,of which conventional hydropower is 340 million kilowatts,accounting for more than 50%of non-fossil energy consumption.The international emission reduction target of reaching15% of annual non-fossil energy consumption plays a pivotal role.Promoting the rational development of hydropower will not only effectively guarantee country’s clean power supply,but will also promote the rapid economic and social development of our country in all aspects.Reservoir power generation dispatching rules are the control rules summarized according to the long series of inflow,storage capacity and outflow processes of hydropower stations,which are used to effectively control the real-time dispatch of the reservoir.The existing reservoir dispatching rules are mainly manifested as conventional dispatching and optimized dispatching.Although each has its own research results,there are still certain shortcomings.The scheduling diagram method of conventional scheduling can simply and clearly guide the operation of the reservoir without considering the forecasted incoming water,and it is difficult to ensure the optimality of the scheduling method.Optimal dispatching models and methods,it is difficult to guarantee optimality and solution efficiency at the same time,and the optimal dispatching method is not very interpretable when making reservoir dispatching decisions.Most of the optimal dispatching methods are extracted because they fail to consider the randomness of runoff.There is a big deviation in the scheduling rules.In order to solve the above problems,this paper generates random runoff scenarios by analyzing the characteristics of runoff.Based on the principle of marginal benefit and the principle of water balance,the mechanism and method of the reference line model for reservoir operation are proposed,which provides a new way for rationally constructing an optimal operation model of reservoir power generation Ideas.The main content and innovation results of this article include:(1)Random runoff scene generation for storage.Aiming at the random characteristics of runoff,this article elaborates on the relevance of runoff in detail.Through the analysis of runoff autocorrelation and time period correlation,the deterministic description and random description methods of inbound runoff are introduced.In order to accurately describe the random factors of runoff,the scenario generation theory is used to reduce the combination of random runoff scenarios through the transition probability of runoff state,and prepare runoff input scenarios for model calculation.(2)Construction of reference line model for reservoir optimal dispatch operation.Based on the experience of reservoir dispatching,this paper analyzes the energy changes in the process of reservoir power generation from the perspective of energy conversion of reservoir power generation,and proposes that reservoir dispatching should follow the two principles of "high hydropower generation" and "avoid water abandonment".Based on the marginal principle,analyze the benefits of the reservoir during the storage period,and construct a water storage indicator line to guide the storage strategy of the reservoir in each period.In order to ensure the normal operation of the reservoir during the dispatching process,the minimum limit output is used to reversely push the minimum storage limit line of the reservoir.The two together constitute the operational reference line for the optimal dispatch of the reservoir,and provide decision support for the reservoir’s pursuit of maximum benefit power generation.(3)Case Analysis.Taking DJK Reservoir as the research object,the relevant characteristics of the inflow runoff of the reservoir are analyzed,and the random scene of runoff is generated through the state transition probability matrix of the runoff.According to the generated 50 sets of random runoff scenarios,the random operation reference line model of the DJK reservoir is obtained.Select 30 random runoff scenarios,and use the obtained random operation reference line as the dispatch criterion for power generation dispatch.The average annual power generation obtained is compared with the stochastic dynamic programming method.The results of the operation reference line model proposed in this paper are mostly better than the random The dynamic programming method has greatly improved the computational efficiency of the model,which verifies the applicability and superiority of the model.