Study On Multi-objective Optimal Operation Of Cascade Reservoirs Considering Water Supply-power Generation-Risk

Aiming at the contradiction between the water supply and water demand in the lower reaches of the Yellow River, the multi-objective operation of Xiaolangdi and Xixiayuan reservoirs was studied which based on water supply-power generation-risk. By analying risk factor of reservoir operation, the index system of reservoir operation risk was established. On this basis, the multi-objective optimization operation model of cascade reservoirs was constructed, and the multi-objective optimization algorithm was applied to solve it. The research made a contribution to coordinate the contradiction between water supply and water demand and then the risk of water resources utilization could be reduced. Through the calculation,the contents and achievements obtained in this paper were as follows:(1)According to the risk of- reservoir operation concept, the risk factors of reservoir operation were identified, and risk index system which included lack of power insufficient risk,the ratio of water danage and water damage dept indexes was constructed, which lay the foundation for further water supply-power generation-risk of Xiaolangdi and Xixiayuan cascade reservoirs and contributed for the risk of multi-objective operation research.(2)A multi-objective optimization operation model of cascade reservoirs was established,which was based on the maximum of the cascade reservoirs generation, the minimum water shortage and the minimum comprehensive risk rate. The non dominated nearest neighbor immune algorithm(NNIA) was used to solve the multi-objective optimization model.(3) Through model solution, the schemes with development and utilization of water resources of five typical years were obtained through model solution with the increase of the coming water. And we also analysed three objectives distribution. The calculation results showed that: the comprehensive risk of Xiaolangdi and Xixiayuan cascade reservoirs was decreased. During the extra low flow year, with the increase of power generation, the water supply decreased, and the ratio of comprehensive risk firstly decreased and then increased. In the other typical years, with the increase of power generation, the water supply decreased, and the ratio of comprehensive risk was decreased gradually.(4)Water supply quantity was the main effect of Xiaolangdi and Xixiayuan reservoirs operation risk factors. In the flood season and before the main flood season, the impact of risk factors on reservoir comprehensive risk was relatively small, and in the period of water supply,the impact was relatively large.(5)Based on Fuzzy optimization model, the resonable operation plan was inquired, which could receive a greater comprehensive benefits of the operation with Xiaolangdi and Xixiayuan cascade reservoirs.