Proposed Control Method of Doubly Fed Induction Generator Rotor Side Converter Based on System Frequency Regulation

Abstract

With the more penetration of wind power based on the DFIG wind turbine to the grid, there is increasing significance for controlling output power in order to meet power system requirements and to participate the frequency regulation in the power grid. This paper is presented proposed control method of DFIG implemented in the RSC using system frequency coordinated control. In this study, the GSC is controlled by using modified vector control method while the RSC is controlled by adjusting the rotor dq-axis currents. The quadrature axis current controls by using the active power generating from the frequency deviation and DFIG store kinetic energy, whereas the direct axis current is controlled by using grid reactive power. Moreover, this power is also used as a main parameter besides rotor speed to control the pitch angle blade in the turbine side. To confirm this method study, the system operation is conducted at steady state and transient modes, and the simulation results were carried out using PSCAD software program. The simulation results show that the voltage of DFIG is very stable, and the system frequency response has been improved. Furthermore, this study realized a full rated value of rotor speed and stable operation of DFIG active power at a steady state besides a good transient response. Moreover, the pitch angle control provided adequate control action at dynamic mode to decrease turbine torque hence to lead to safety transient mode operation.