Dual mechanical port power distribution in dual rotor permanent magnet flux switching generator for counter‐rotating wind turbine applications

Abstract

In this paper, a novel dual mechanical port dual rotor counter-rotating permanent magnet flux switching generator (DMPDRCR-PMFSG) for wind turbine applications is proposed. Power distribution between the inner and outer rotors of the proposed DMPDRCR-PMFSG that contributes to the cumulative output power is investigated. The proposed DMPDRCR-PMFSG shares a stator connected back-to-back through flux bridge. The flux bridge physically isolates the armature winding of the inner and outer ports. Furthermore, the flux bridge provides a flux path to magnetic flux of the inner and outer ports that contributes to cumulative output power. Quantitative comparative analysis of the inner and outer ports illustrates that under static analysis 18.57% more flux, 23.95% highly induced back-EMF, 31.08% of enhanced average torque are obtained in the outer rotor at the cost of 64.01% and 22.7% increase in cogging and torque ripple ratio, respectively. Comparative analysis with a number of turns reveals that the outer port offers 41.17% higher output power and 7.09% improved efficiency at the cost of 42.52% increase in voltage regulation factor. Finally, coupled overload and over-speed analysis shows that despite a stable and low voltage drop ratio, the outer port offers 4.65% higher output voltage. Analysis shows that in the proposed DMPDRCR-PMFSG, the outer port has a dominant contribution to the cumulative power distribution.

Comparative analysis of torque-adding wind energy conversion systems with a counter-rotating vs. conventional electric generator

“…Regarding the electric generators for WECS, Booker et al (2010) andHabash et al (2011) proposed the use of counter-rotating electrical generators for wind turbine applications in urban areas, which have a mobile rotor (GR) and mobile stator (GS) rotating in opposite directions due to their increased energy performance compared to the conventional (with a fixed stator GS) generators. The counter-rotating generator was further investigated in terms of performance and rotor topology by Kutt et al (2020), Egorov et al (2021), andMirnikjoo et al (2021) and in terms of optimized system configuration with counter-rotating rotors (Mirnikjoo et al, 2020;Ullah et al, 2022a;Ullah et al, 2022b). Cho et al (2017) analyzedthe performance and control of a WECS with counterrotating rotors and counter-rotating generator and concluded that this configuration can lower the tip speed ratio at which the power curve attains its maximum almost by half in comparison to the single-rotor system.…”