A Novel Control Strategy for a Variable-Speed Wind Turbine With a Permanent-Magnet Synchronous Generator

TLDR

The study proposes a novel control strategy for a direct‑drive permanent‑magnet synchronous generator in a stand‑alone variable‑speed wind turbine. The strategy employs a generator‑side converter with maximum‑power‑point tracking, an output voltage and frequency controller, a dump‑load resistor with chopper control to dissipate excess power, and a dc‑link voltage regulator, supported by dynamic dc‑bus modeling and small‑signal analysis. Simulations demonstrate that the controllers achieve maximum‑power extraction while maintaining voltage and frequency under varying wind and load, exhibiting excellent dynamic and steady‑state performance.

Abstract

This paper presents a novel control strategy for the operation of a direct-drive permanent-magnet synchronous-generator-based stand-alone variable-speed wind turbine. The control strategy for the generator-side converter with maximum power extraction is presented. The stand-alone control is featured with output voltage and frequency controller that is capable of handling variable load. The potential excess of power is dissipated in the dump-load resistor with the chopper control, and the dc-link voltage is maintained. Dynamic representation of dc bus and small-signal analysis are presented. Simulation results show that the controllers can extract maximum power and regulate the voltage and frequency under varying wind and load conditions. The controller shows very good dynamic and steady-state performance.