Full‐Capacity Wind Turbine with Inertial Support by Adjusting Phase‐Locked Loop Response

Abstract

This study presents a new concept for full-capacity wind turbines (WTs) to emulate inertial response behaviour by optimising phase-locked loop (OPLL). The proposed OPLL-based concept can make full-capacity WT spontaneously respond to frequency events in grid with no more need for frequency measurement and calculations of its variation or differential, which are usually required to calculate the desired extra support power or chosen to trigger a predetermined active power shape etc., in common methods. Comprehensive analysis and comparisons are presented for full-capacity WT with two different generic control structures by establishing corresponding motion equations with regard to the active current dynamics. The established motion equations theoretically indicate that PLL dynamics and the related active power controls are in the equally important positions and greatly influence the frequency response behaviours of full-capacity WT, which constitutes the theoretical basis of the proposed OPLL-based methodologies. Simulated results demonstrate the feasibility and correctness of the OPLL-based methodologies. The influences of key parameters concerned corresponding to each proposed OPLL-based methodology are studied. Finally, the proposed methodologies for two generic control structures are also briefly compared and evaluated.