Risk Assessment Method for the Oscillation of Renewable Energy Grid-connected System Based on Frequency Domain Impedance
With the increasing installed capacity of renewable energy,how to assess the risk of sub/sup-synchronous os-cillation in power system caused by it is currently a critical concern for grid operation.This paper proposes a risk assessment method for the oscillation of renewable energy grid-connected system based on frequency domain impedance.Firstly,the frequency domain admittance model of each component in the system is used to form a network node admit-tance matrix so as to calculate the equivalent impedance of the network at the system side of the grid connection point of the renewable energy station,which can accurately reflect the structural characteristics of the power grid and the dynamic characteristics of other equipment in the grid.Combined with the impedance characteristics of the renewable energy sta-tion,the oscillation risk of the grid-connected renewable energy station is evaluated by impedance analysis.The nodal analysis is utilized in the method,which is easy to implement algorithmically and can adapt to the changes of system structure and operation mode,thus the influence of dynamic components on the grid side can also be fully reflected.The data of topological structure and power flow provided by the phasor measurement unit(PMU)can be used to evaluate the oscillation risk of grid-connected renewable energy stations in the system.Taking an actual power system in a certain area as the research object,we perform the risk assessment of subsynchronous oscillation by using the proposed method.The correctness of the assessment results and the effectiveness of the assessment method are verified based on the eigenvalue method and time domain simulation.
renewable energy grid-connected systemsub-synchronous oscillation(SSO)impedance modeldoubly-fed induction generator(DFIG)risk assessment
万方数据
维普
