Impact of Energy Storage on Security-Constrained Unit Commitment of Power System with Wind Power Integration

Abstract

With the increasing of wind power penetration rate in large power grid, it is of great importance to analyze the impact of wind power on unit commitment of power system and economic dispatch. In the security-constrained unit commitment problem, the introduction of wind turbine can reduce the operating cost of thermal power units and improve the economy of system operation. Because the energy storage system has the characteristics of fast two-way regulation, it can improve the power grid’s ability to absorb wind power and the economy of the system operation. By controlling the charging and discharging of energy storage, it can provide certain flexibility for determining the system unit commitment scheme. Therefore, by considering the forecast error influences of wind power and load, this paper introduces the energy storage system into the security-constrained unit commitment of power system with wind power. Moreover, the constraint condition of rotating reserve opportunity based on trust theory is introduced to avoid over configuration of backup. Thus, the uncertainty of wind power can be effectively improved and the operation cost of the system can be reduced. In addition, the paper compares and analyzes the changes of unit commitment status and system operation cost with or without energy storage, as well as the influence of energy storage parameters and the way of access system (close to wind power side, load side and decentralized access) on the unit commitment model under wind power curtailment condition. Finally, the linearized security-constrained unit commitment model is analyzed and validated with 10 units system.