Research on Equivalent Modeling of PMSG-based Wind Farms using Parameter Identification method

Aiming at the problem that traditional equivalent modeling method of wind farms has large dynamic errors when there is a large difference in wind speed distribution, this paper proposes a method for equivalent modeling of permanent magnet synchronous generator (PMSG) based wind farms using parameter identification. This method is based on traditional single-machine equivalent model and involves three critical steps. Step 1, performing the trajectory sensitivity analysis of wind turbine generator operation parameters under active output power and the bus voltage to determine the key identification parameters. Step 2, the minimum error of active output power between equivalent model and the actual wind farms is taken as the objective function. Step 3, the improved genetic algorithm (GA) is employed to identify the determined key parameters, so as to obtain the optimized equivalent model by parameter identification. In PSCAD / EMTDC, the dynamic errors between both two equivalent models and actual wind farms under three-phase short-circuit faults are compared, and the proposed method is verified. The result shows that the identification of key wind turbine generator operation parameters can effectively improve the accuracy of single-machine equivalent model of wind farms.