Study on Flood Control Operation of Parallel Reservoir Groups Considering the Difference of Solution Order

In solving the joint optimal operation problem of reservoir groups, traditional optimization methods suffer from the defects of “dimension disaster”, premature convergence, and low efficiency. In this paper, an improved dynamic programming (DP) method is proposed, which reduces the dimension of the DP by using dynamic water level limits and a variable discrete mechanism. This approach improves computational efficiency while ensuring calculation accuracy. Taking the 5-reservoirs system in the Liuxi River Basin as the research object, and aiming at minimizing flood peak discharge at the control section in the lower reaches, an optimal operation model for joint flood control of the reservoir group is established. Based on the improved DP with dimensionality reduction, and considering the differences in scheduling order of the reservoirs, the model is solved. Through the comparison of the calculation results, it is found that the peak flow at the outlet section of the basin from positive sequence optimization is reduced by 24% compared with conventional operation. This fully exploits the role of peak shaving and shifting, which is conducive to the safety and stability of the downstream river. In addition, the flow peak obtained by the reverse sequence optimization at the outlet section is the smallest, being 12% lower than the positive sequence optimization and 0.7% lower than the mixed sequence optimization. This better achieves the purpose of joint peak cutting and peak staggering. The new algorithm can improve computational speed, and the model that offer higher safety and stability in scheduling has practical significance.