Wind-Thermal Generating Unit Commitment Considering Short-Term Fluctuation of Wind Power

Abstract

The integration of large-scale wind power in a power grid brings tremendous challenges to the power system operation because of the variability of wind power. Adequate spinning reserve is always required for effective accommodation of wind power variability by the automatic generation control system. The generation schedule and required spinning reserve are usually determined by hourly unit commitment, but the system frequency regulating process under wind power intrahour fluctuation is ignored. This increases the system operation risk. A novel wind-thermal generating unit commitment method considering short-term (<1 h) fluctuation of wind power (SFWP) is presented. A simulation model based on the k-means clustering technique is developed to describe the SFWP information, and the system frequency regulation is incorporated as the spinning reserve constraint of the unit commitment model. The proposed method enables more accurate assessment of the required spinning reserve capacity than the existing methods. It also improves the security of power system operation. Case studies are presented to demonstrate the effectiveness of the proposed method.