Comparison of primary frequency control methods for wind turbines based on the doubly fed induction generator

Abstract

The penetration of large levels of wind energy leads to technical problems affecting the frequency stability of the power system. Naturally, a wind power plant does not provide an inertial response nor does it regulate the system frequency in case of generation-demand imbalance due to the decoupling between the rotor speed and the grid frequency through the electronic converter (AC/DC/AC). This paper reviews, analysis and compares the performance of four control methods based on the modification of the electromagnetic torque set point and one of the mechanical torque. These methods allow that activation of the wind turbine inertia when a frequency deviation occurs, contributing to the regulation of the system frequency similarly to a conventional synchronous generator. However, wind turbines only change their operating point for a limited time and not permanently.