Frequency support Scheme based on parametrized power curve for de-loaded Wind Turbine under various wind speed

TL;DR

This paper introduces a novel frequency regulation scheme for de-loaded wind turbines that modifies the power-rotor speed curve, eliminating control gains and adapting to various wind speeds to improve system frequency response.

Contribution

It proposes a gain-free, adaptive frequency support method based on parametrized power curves, suitable for variable wind speeds without needing wind speed measurements.

Findings

Improves frequency response of power systems with wind turbines.

Ensures stable operation of DFIG-based wind turbines under variable wind conditions.

Prevents rotor speed overdeceleration during frequency regulation.

Abstract

With increased wind power penetration in modern power systems, wind plants are required to provide frequency support similar to conventional plants. However, for the existing frequency regulation scheme of wind turbines, the control gains in the auxiliary frequency controller are difficult to set because of the compromise of the frequency regulation performance and the stable operation of wind turbines, especially when the wind speed remains variable. This paper proposes a novel frequency regulation scheme (FRS) for de-loaded wind turbines. Instead of an auxiliary frequency controller, frequency support is provided by modifying the parametrized power versus rotor speed curve, including the inertia power versus rotor speed curve and the droop power versus rotor speed curve. The advantage of the proposed scheme is that it does not contain any control gains and generally adapts to different wind speeds. Further, the proposed scheme can work for the whole section of wind speed without wind speed measurement information. The compared simulation results demonstrate the scheme improves the system frequency response while ensuring the stable operation of doubly-fed induction generators (DFIGs)-based variable-speed wind turbines (VSWTs) under various wind conditions. Furthermore, the scheme prevents rotor speed overdeceleration even when the wind speed decreases during frequency regulation control.