Mid-long term optimization of reservoir operation for hybrid pumped storage power plant

A mid-long term optimal reservoir operation model is built for the hybrid pumped storage power station,which takes the maximum mean annual energy generation for multiple years as its objective.The dynamic programming algorithm,which has two control variables:water flow and pumping time,is applied to discretize the long data sequence of water level and pumping time for searching their best combinations for different periods.Case study shows that,with the added pumped storage units,the mean annual energy generation increases from 2 063 million kW·h to 2 306 million kW·h,the firm power increases about 0.01 million kW,the water level is slightly higher in all periods,and the discretization error is less than 0.4 % when the step of discretized pumping time is 1 hour per day.