Study On Low Frequency Oscillation And Damping Control With Large-scale Wind Power Integration

Recently, with the integration of large-scale wind power and the development of interconnected large power system, the probability of low frequency oscillation have increased. Therefore, it is necessary to provides a method to identify low frequency oscillation and to control the damping ratio. The method can be employed by the dispatchers to find low frequency oscillation mode in the power system, improve damping ratio, and reduce the reduction of low frequency oscillation.Method of low frequency oscillation identification and strategy of damping control is proposed, and example verification based on Gansu power network is carried out.Firstly, the influence of large-scale wind power integration on the damping ratio of the power system is analyzed, and the power system model considering wind power integration is built. Secondly, Rayleigh quotient iteration is adopted to calculate the eigenvalue and eigenvectors of the state matrix of the power system. Thirdly, eigenvalue is selected by its frequency, damping ratio, and etc. Finally, the low frequency oscillation mode of the power system with large-scale wind power integration is identified.Strategy of damping control considering wind power integration is proposed. It is based on the identification method. Firstly, analyze the influence of generator output on damping ratio, and choose the sensitivity of damping ratio against generator output as the quantitative index, and method of equal and opposite adjustment is adopted to propose the strategy of damping control.This paper builds the low frequency real-time identification calculation model based on Gansu power network. The model includes pretreatment of real-time data, internal and external network fitting, and etc. The simulation based on the model demonstrates the feasibility and effectiveness of the method of low frequency identification and the strategy of damping control.