Inertial Response of Doubly-fed Induction Generator with the Phase-locked Loop

With the development of wind power, the problem of system inertia and frequency dynamic deterioration caused by large-scale wind power integration is becoming more serious. The inertial response of wind turbines is worthy of attention and research. In this paper, the quantitative calculation method of the equivalent virtual inertia time constant H eqDFIG of the doubly-fed induction generator (DFIG) with the phase-locked loop (PLL) is studied, and the influence of the PLL on the inertial response of DFIG is analyzed. Firstly, a simplified model of DFIG with the PLL is established. By calculating the electromagnetic torque increment, the equivalent virtual inertia time constant H eqDFIG of the DFIG considering the dynamic characteristics of the PLL is obtained. And the influence of the PLL parameter variation on the virtual inertial response of the system is analyzed. Simulation verification proves the correctness of the conclusion.