Hydro-Thermal-Wind Coordination in Day-Ahead Unit Commitment

With large-scale wind power integration, more reserve has to be scheduled to ensure power supply safety. Proper hydro-thermal coordination is able to provide essential reserve. This paper constructs a unit commitment (UC) model that coordinates hydro and thermal power generation to support secure and economic wind power integration. Several reserves, including an online generation reserve, a ramping reserve and a transmission capacity reserve, are identified and considered in this UC model to counteract the variability and uncertainty inherent in wind power. The reserves are determined based on interval programming and provided through hydro-thermal coordination. By scheduling reserves, this UC model guarantees a reliable power supply while properly maintaining hydropower station reservoir water levels. Finally, numerical results on an eight-bus system and a real-world large-scale power system show the effectiveness of this UC model for guaranteeing system security with high wind power penetration.