Abstract: Complementary dispatching of cascade hydropower plants and photovoltaic (PV) power plants is always a hot topic in research. To improve the complementary effect of the hydropower plants of different regulation types on the PV power output, this paper presents a new method of short-term complementary dispatching based on a concept of equivalent power plants. Considering the different characteristics of PV power generation, we use the K-means clustering method to divide multiple PV convergence areas. Each hydropower plant is combined with its corresponding convergence area for complementary operation; through analysis of peak regulating indexes, the optimal combination of hydropower and PV plants is found for every time period to construct an equivalent power plant. Then, these equivalent plants and the other hydropower plants are taken as the object for joint peak regulating and dispatching. This new method is verified through simulating a system of five cascade hydropower plants on the Lancang River and seven photovoltaic power plants in Yunnan. It improves the overall peak regulation significantly in comparison with several other models.

Key words: cascaded hydropower plants, photovoltaic power stations, hydropower-photovoltaic complementary, short-term dispatching, equivalent power plant