A Multi-State Model for Exploiting the Reserve Capability of Wind Power

The strong volatility of load and intermittent generations may lead to the tension of operating reserve in the modern power system. However, the conventional operating reserve providers, such as coal-fired generating units, are costly and not environment friendly. To address the growing needs for operating reserve, the day-ahead market for operating reserve have been launched in practice, such as Midwest ISO of the US. The high penetration of renewables has contributed to the increasing demand for the flexible dispatch in the generation side. Renewable generation, such as wind power, is being allowed to participate in the markets by providing auxiliary service. Therefore, wind power can be utilized in a positive way by providing operating reserve. A temporal and spatial multi-state model is developed to exploit the potentiality of wind power for providing operating reserve in this paper. First, the multi-state model for different wind farms is formulated based on the predictive distribution of wind power and correlations among different time periods and different wind farms. Second, the upward and downward reserve capacity of wind power is analyzed quantitatively based on the proposed multi-state model. Then, the adjustable reserve capacity of wind power is utilized in a stochastic day-ahead unit commitment (DAUC) model to determine the optimal operating reserve schedule by balancing the generation economy and wind power dispatch margin. The forecast day-ahead expectations and the possible real-time variations of wind power are considered in the proposed DAUC model. Illustrative results demonstrate the effectiveness of the proposed model.