Enhancing flexibility of power systems by exploiting operational controllability of large-scale wind farms

摘要

Even though increasing wind power generation significantly benefits the greening of power system generation, the intrinsic uncertainty and variability associated with large-scale wind generation greatly challenge the current power system operation, such as unit commitment (UC) and economic dispatch. So far, major wind farms are straightforwardly integrated into the existing UC framework as negative loads and operated with a wind-in-priority mode. With the prompt development of the control techniques of wind generators, such as switching on/off or fast pitching control, this manner of operation may underestimate the controllability of wind farms and result in the lack of operational flexibility of the power system. This paper addresses the issue by exploiting the controllability of wind farms in UC decision while considering its inherent uncertain nature. First, the wind generation controllability is modeled as an adjustable scenario set associated with prediction errors. And then a modified two-stage stochastic UC model is formulated to incorporate the operational controllability of wind farms. A modified IEEE 39-bus system is employed to demonstrate the proposed methodology. Simulation results show that the utilization of wind generation controllability can considerably benefit the economy, reliability, and flexibility of power system dispatch. (c) 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.