Primary Frequency Regulation Control of Wind Turbines Based on Variable Power Tracking

Abstract

Due to a large number of grid-connected wind turbines don't have the ability to respond to system frequency changes, problems on frequency stability of power system have become increasingly prominent. At present, the primary frequency regulation of wind turbines is mostly based on the method of additional frequency regulation control to change the reference value of electromagnetic power, so as to realize that wind turbines can participate in the system frequency regulation. However, the method of additional frequency regulation control does not t consider the conflict of power increment between the power tracking controller and the frequency regulation controller, which lead to the power increment required for the primary frequency regulation can't reach the target value. Based on this issue, the paper combines the original power tracking technology of wind turbines with the existing frequency regulation technology, and change the signal of frequency deviation by the power tracking curve of the wind turbine, which realize the inertial response and primary frequency regulation of the unit through the fast active power control of the wind turbine. That the purpose of frequency regulation is realized and the power tracking curve is changed, by converting the active output required for the frequency regulation control into the increment load reduction. The simulation results show that, based on the control method in the paper, the double-fed wind turbine can fully achieve the target increment needed for primary frequency regulation, which makes the wind turbines more reliable and effective to participate in system of frequency regulation.