Risk-Aware Joint Bidding Strategy for Cascade Hydropower and Wind Power in Electricity Spot Markets Considering Vibration Zone Impacts

To mitigate the compliance deviation risk induced by wind power output fluctuations, this paper proposes a two-stage joint bidding model for cascaded hydropower–wind systems within the electricity spot market framework from a price-taker perspective, explicitly accounting for the decision maker’s risk preferences. To capture the impacts of hydropower vibration zones on joint bidding decisions, the feasible output range of hydropower units is divided into multiple safe operating sub-intervals, and vibration zone avoidance is modeled using binary decision variables; meanwhile, penalty terms are incorporated into the objective function to suppress vibration zone crossing behaviors. From a risk-aware decision-making perspective, Conditional Value-at-Risk (CVaR) is adopted to quantify the downside tail risk of bidding revenues, and a risk factor is introduced to flexibly adjust the decision maker’s risk attitude. Finally, a case study based on a cascaded hydropower system and an associated wind farm in Southwest China is conducted to demonstrate the effectiveness of the proposed joint bidding strategy and to examine the impacts of risk preferences and vibration zone considerations on joint bidding outcomes.