This article presents a decentralized current control approach for a nine-phase wind turbine generator. This type of generator has three different three-phase stators sharing the same machine yoke, connected to the grid by means of three different Voltage Source (VS) back-to-back power converters. Due to the machine configuration, magnetic couplings are present between the three stators, complicating the design and implementation of the machine current controllers. Rather than a centralized control approach, this paper proposes a methodology to design a decentralized machine control to regulate the active and reactive power flowing through each stator independently. A complete dynamic analysis is performed in order to design the controller to reduce the coupling effects within the machine while ensuring a proper dynamic performance. The control strategy is validated through simulation and experimental results.
Index TermsPermanent magnet machines, multiphase variable-speed drives, decentralized control, wind energy.