Improvement of primary frequency control by inertial response coordination between wind and conventional power plants

The constant increasing of wind power penetration leads to more and more retirement of conventional power generators. Since modern wind energy conversion machines are decoupled from the grid by the back-to-back voltage-based converters, they are not able to contribute to inertial response. Therefore, the reduced inertia of power systems at a high wind-power penetration level causes the greater rate of change of frequency following a power imbalance event and may bring the system to the crucial stability situation. In this study, the supported inertial response from the variable-speed wind turbines is based on electrically voltage-based converter control taken from stored kinetic energy of rotating mass of wind turbines. To enhance the frequency response, we proposed a new inertial coordination control between controlled wind turbines and conventional generators. So as to investigate the performance of the proposed method, we introduced a new primary frequency response metric. Also, a comparison between the effects of temporarily inertial support from wind farms and coordination of inertial support between wind and conventional power plants is done. The simulation results on an updated version of IEEE-39 bus power system in the presence of high penetration of wind farms indicate that by using the coordination control scheme, the frequency performance is significantly improved. The simulation is performed by MATLAB SimPowerSystems block set.