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In this paper, counter rotating dual rotor wound field flux switching wind power generator is revisited to study the generating characteristics of the AC output power curves based on finite element analysis (FEA) and experimental study. Analysis are performed under dynamic conditions, such as variable resistance, field excitation and speed. Also, electromagnetic performance is studied under variation of the field and armature currents. Analysis reveals that outer port machines with higher power capability and better electromagnetic performance compared to the inner port counterparts, although with higher fluctuations exhibited on the torque profiles of the former due to higher slotting effects. From the power generation characteristics curves, it is clear that the developed wind generator is able to produce reliable performance over a wide operating range. The accuracy of the FEA predicted results are validated, experimentally. The cover image is based on the Research Article Generating characteristics and experimentation of counter rotating dual rotor wound field flux switching wind generator by Wasiq Ullah et al., https://doi.org/10.1049/elp2.12374. [ABSTRACT FROM AUTHOR]

In this paper, a novel low‐cost dual port dual rotor‐field excited flux switching generator (DPDR‐FEFSG) is proposed for low power rooftop wind turbine integrated with DC‐micro‐grids. The proposed DPDR‐FEFSG incorporated inner/outer machine to design a dual rotor structure with dual output port. Due to the existence of field excitation in DPDR‐FEFSG, overall machine cost is reduced and offered excellent flux regulation capabilities. Furthermore, single tooth non‐overlapped armature winding and toroidally wounded field winding significantly shorten end winding that reduces copper losses. Additionally, compared with the existing single‐bus DC‐micro grids system, the proposed DPDR‐FEFSG exhibits two‐port output which makes it feasible for low‐voltage (12–24 V) and high‐voltage (48 V) applications connected to the DC micro‐grids without the requirements of extra power electronics circuitry. The proposed DPDR‐FEFSG is investigated under variable field excitation and variable rotor speed. In order to achieve the desired voltage level at low and high port without frequency variation, AC–DC rectification is employed. Analysis reveals that proposed DPDR‐FEFSG offers dual output port from inner and outer machines. This dual port makes it feasible for wind turbine integrated to multi‐port DC micro‐grids. Due to availability of different voltages at various ports, different load classes are incorporated without the requirements of extra power electronics circuitry and thus reduce overall cost. Finally, a prototype is built and tested to confirm the validity of the proposed concept and finite element analysis (FEA) results. [ABSTRACT FROM AUTHOR]

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 DMPDRCRPMFSG 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. [ABSTRACT FROM AUTHOR]

Flux switching motors (FSMs) with conventional stator slots have a relatively low copper slot filling factor. In this article, a new octane modular stator with pentagon-shaped slot electrically excited FSM (EEFSM) that has a comparatively higher copper slot filling factor is analyzed analytically to reduce computational complexity, high computational time, and high drive storage. The analytical results of the proposed EEFSM are validated via the finite element method. Furthermore, the initial design is optimized to improve the electromagnetic performance, and finally the prototype is fabricated and tested experimentally. There is good agreement among the analytical, finite element analysis (FEA), and experimental results with variations of 3%–5%. The average torque of the optimized design has improved by 30%, cogging torque is suppressed by 36%, and torque ripples have reduced by 38%, which have improved the performance of EEFSM in terms of low acoustic noise, low vibration, and longer motor lifetime. The proposed octane modular stator can be easily unfolded for windings maintenance, coils placement, and motor transportation in case of large-size applications. [ABSTRACT FROM AUTHOR]

The cover image is based on the Research Article Generating characteristics and experimentation of counter rotating dual rotor wound field flux switching wind generator by Wasiq Ullah et al., https://doi.org/10.1049/elp2.12423. [ABSTRACT FROM AUTHOR]

Flux switching machines (FSMs) encompass unique features of conventional direct current machine, permanent magnet (PM) synchronous machine and switch reluctance machine. Permanent magnet FSM (PMFSM) is capable of high torque density and applicable for high‐speed application, however conventional PMFSM exhibits demerits of high PM volume, high torque ripples and significant stator flux leakage. In this paper, a novel consequent pole E‐core stator PMFSM is proposed and compared with conventional topology utilising 2D finite‐element analysis (2D‐FEA). Finite‐element analysis revealed that proposed design enhanced flux modulation effects by introducing flux bridges and flux barriers as a result reduced cogging torque by reducing 46.53% of the total PM volume, reduce torque ripples by reducing PM slot effects and reduce flux leakage utilising flux bridges in the stator. Furthermore, analytical model for flux linkages, cogging torque, mechanical torque, no load and on‐load magnetic flux density (MFD) is developed for initial design of conventional and proposed model. 2D analytical methodologies resolve equivalent magnetic circuits for open‐circuit flux linkages, Fourier analysis for cogging torque, Laplace equations for MFD and Maxwell stress tensor for mechanical torque. Finally, results obtained from 2D‐FEA and analytical methodologies are validated and compared. [ABSTRACT FROM AUTHOR]

Front Cover: Investigation of low-cost dual port co-rotating dual rotor field excited flux switching generator for low-power rooftop wind turbine integrated with multi-port DC micro grid The cover image is based on the Research Article I Investigation of low-cost dual port co-rotating dual rotor field excited flux switching generator for low-power rooftop wind turbine integrated with multi-port DC micro grid i by Wasiq Ullah et al., https://doi.org/10.1049/rpg2.12561. [Extracted from the article]