Bidding-clearing-scheduling coordinated optimization for cascade hydro-wind-photovoltaic alliances in electricity spot markets: A multi-stage framework

Variable renewable energy (VRE), represented by wind power and photovoltaic, is gradually participating in the spot market, but the uncertainty of its output leads to its weak market competitiveness. VRE jointed with cascade hydropower with flexible regulation capability is an effective solution; however, how to formulate a reasonable bidding strategy and scheduling program to increase the revenue of the alliance and simultaneously reduce the water abandonment caused by cascade hydropower's power-hydraulic mismatch is an urgent problem to be solved. To this end, this study proposes an integrated multi-stage optimization framework for bidding, clearing, and scheduling(MBCS) of cascade hydro-wind-photovoltaic alliances(CHWPA) participating in the spot market. In this framework, the load scenario generation method is used to describe the load uncertainty, estimate the clearing price, and establish an optimized bidding model based on the estimated clearing price. Then, the Shapley value method is used to distribute the alliance income after market clearing, and a redistribution model for the winning bid output is established to minimize the water abandoned. Finally, the effectiveness of the alliance bidding framework is verified through case simulations. The results show that the proposed alliance bidding framework can increase up to 118 % of VRE revenues, 56 % of hydropower plant revenues, and reduce 96 % of water abandonment compared to individual bidding.