Abstract:

For the current stability analysis methods of sub-synchronous oscillation,most of the characteristics are analyzed by models,but in practice,photovoltaic models are difficult to obtain directly.The state space model of photovoltaic was established,and the dq-axis current and voltage of the photovoltaic power plant were extracted.The random subspace method was used to analyze the photovoltaic transfer function model.A photovoltaic model was built on the simulation platform to verify the effectiveness of the random subspace method.Finally,according to the data of sub-synchronous oscillation recording of an actual photovoltaic power plant,it is concluded that the phenomenon of sub-synchronous oscillation occurs during the recording of the photovoltaic power station.This method provides a feasible method for monitoring and early warning of sub-synchronous oscillation in actual practice.

Key words: photovoltaic power plant, photovoltaic impedance identification, random subspace, photovoltaic oscillation, impedance method