Investigation on Multi-star Structures for Large Power Direct-drive Wind Generator

Abstract

In order to increase the power capability of direct-drive PM wind generators with respect to established quality criteria like the electromagnetic torque and the power transferred to the grid, a polyphased multi-star system is studied. The influence of the number of stars, their phase shift and the waveform of the electromotive force are investigated. The possible configurations, i.e. the numbers of magnets and slots, are found and compared.

Current Control of a Six-Phase Induction Generator for Wind Energy Plants

“…Among the multiphase machines, multiple three-phase winding machines are widely studied [5][6][7][8][9]. These machines can be conveniently obtained by rewinding standard threephase machines, and such modular nature allows full exploitation of the readily available three-phase converters.…”

Finite Element Analysis of a Permanent Magnet Machine with Two Contra-rotating Rotors

“…The benefits of eliminating mechanical gearboxes from large power drive trains have been recognized in a wide range of applications, such as ship propulsion drives [1], electric car motor drives [2], wind energy conversion systems [3], and marine current energy conversion systems [4]. In direct variable-speed drives, permanent magnet (PM) machines have become popular due to their typically high power densities and high efficiencies over a wide range of operational speeds.…”

PI tuning of five-phase drives with third harmonic injection

“…Electrical and hybrid vehicles (Gao & Parsa, 2007), aerospace (Levi et al, 2007b), ship propulsion (Parsa & Toliyat, 2005b) and wind power applications (Vizireanu et al, 2007) are examples where the use of multi-phase drives can be advantageous. Among multi-phase drives, five-phase ones provide not only power splitting reduced vibrations and less acoustic noise, but also allows the use of a third harmonic injection (THI) together with the fundamental component.…”