This paper explains the state of art of switched flux wound-field machines (SFWFMs). The main advantage of these SFWFMs when compared with induction machines, synchronous machines, direct current machines, etc. is that all the active parts such that armature coil and field excitation coil are located on the stator while the rotor part consists of only iron material without windings. This makes the machine more robust, simple structure, and more suitable to be used for high-speed applications, compared to induction machine which has low mechanical strength, less torque desnity, and low power factor. Theories, numerical and technical literature of different SFWFM are described and analysed. Merits and demerits of different SFWFM structure are discussed. This paper categorized SFWFM topologies on the basis of their structure, flux linkage, cogging torque, average torque, and efficiency.

Computational complexity, magnetic saturation, complex stator structure and time consumption due to repeated iteration compels researchers to adopt alternate analytical model for initial design of electric machines especially Switched Flux Machine (SFM). To overcomes the abovesaid demerits, In this article alternate analytical sub-domain model (SDM) for magnetic field computation in Segmented PM switched flux consequent pole machine (SPMSFCPM) with flux bridge and flux barriers accounting boundary and interface conditions, radial magnetized PMs (RM-PMs) and circumferential magnetized PMs (CM-PMs), interaction between stator slots and inner/outer rotor topologies is proposed. Overall field domain is divided into air gap, stator slots and Permanent Magnet (PM) accounting influence of CM/RM-PMs under no-load and on-load conditions. Analytical expression of field domain is obtained by solving magnetic vector potential utilizing Maxwell’s equations. Based on the magnetic field computation especially no-load and on-load condition, Magnetic Flux Density (MFD) components, open-circuit flux linkage, mechanical torque and cogging torque are computed utilizing Maxwell Stress Tensor (MST) method. Moreover, developed analytical SDM is validated with globally accepted Finite Element Analysis (FEA) utilizing JMAG Commercial FEA Package v. 18.1 which shows good agreement with accuracy of ~98%. Hence, authors are confident to propose analytical SDM for initial design of SPMSFCPM to suppress computation time and complexity and eliminate requirements of expensive hardware and software tools.

Permanent Magnet Flux Switching Machines (PMFSMs) enclose unique features of permanent magnet (PM) synchronous machine, direct current machine, and switch reluctance machine therefore, applicable for high speed brushless AC applications. However, conventional PMFSMs exhibits demerits of high PM volume , high torque ripples , low average torque , lower torque density , power density and leakage flux. In this paper, a new topology of 12S‐13P and 6S‐13P E‐Core PM Consequent Pole Flux Switching Machines (PMCPFSM) with flux barrier and partitioned PM is proposed that eliminate leakage flux, enhanced flux modulation effects through flux barriers and reduces the PM volume up to 46.53%. Moreover, due to non‐linear behaviour of PM and complex stator structure alternate analytical sub‐domain model is utilized for initial design and Multi‐Variable Geometric Optimization (MVGO) is opted to investigate influence of design parameters on electromagnetic performances such as , , and . Analysis and comparison with the existing 12S‐10P E‐Core PMFSM, 6S‐10P E‐Core PMFSM, 6S‐10P C‐Core PMFSM and 12S‐14P C‐Core PMCPFSM reveals that proposed 6S‐13P PMCPFSM produced higher up to 88.8%, suppress maximum up to 14.72% and offer 2.45 times and capabilities, when compared with the aforesaid state of the art.

Design, optimization, and performance analysis of a three-phase field-excited flux switching (FEFS) motor to be employed for the future hybrid electric vehicle (HEV) drive applications is investigated in this paper. The stator of designed motor made of electromagnetic steels is composed of unique field mmf source and armature coils while a rotor is made of iron stack. This design has been evaluated in order to achieve power and torque density higher than 3.50 kW/kg and 210 Nm, respectively, so as to compete with the interior permanent magnet synchronous (IPMS) motor commonly installed in HEV. Given its robust rotor structure, the maximum achievable motor speed went up to 20,000 rpm. To perfect the motor design, a deterministic optimization approach was applied to meet the stringent performance requirements. In addition, experimental analyses were carried out to confirm the effectiveness of the proposed motor. Positively, the proposed FEFS motor has proved to be a suitable candidate of non-permanent magnet motor for efficient and safe HEV drive.

In recent years, flux switching machine (FSMs) has been developed due to the excitation sources are located in the stator and become as an attractive machine that allowing a simple robust rotor structure while provide high torque density. They can be classified into three categories which is consists of field excitation flux switching machine (FEFSM), permanent magnet flux switching machine (PMFSM), and hybrid excitation flux switching machine (HEFSM). The main flux sources for both FEFSM and PMFSM has only field excitation coil (FEC) and PM, respectively whilst HEFSM combines both PM and FECs. In this research, design and performances of a three phase 12S-10P HEFSM in which the field excitation coil (FEC) located external to the PM are investigated. Initially, procedures for the design of the proposed machine that include parts drawing, materials, condition and properties setting are described. Next, coil arrangement test is analyzed to all armature coil slots to confirm the polarity of each phase. Other than that, the flux interaction analysis is performed to investigate the flux capabilities at various current densities. Finally, torque performances are investigated at various armature and FEC current densities.

Recent advancements have led to the development of flux switching machines (FSMs) with flux sources within the stators. The advantage of being a single-piece machine with a robust rotor structure makes FSM an excellent choice for speed applications. There are three categories of FSM, namely, the permanent magnet (PM) FSM, the field excitation (FE) FSM, and the hybrid excitation (HE) FSM. The PMFSM and the FEFSM have their respective PM and field excitation coil (FEC) as their key flux sources. Meanwhile, as the name suggests, the HEFSM has a combination of PM and FECs as the flux sources. The PMFSM is a simple and cheap machine, and it has the ability to control variable flux, which would be suitable for an electric bicycle. Thus, this paper will present a design comparison between an inner rotor and an outer rotor for a single-phase permanent magnet flux switching machine with 8S-10P, designed specifically for an electric bicycle. The performance of this machine was validated using the 2D- FEA. As conclusion, the outer-rotor has much higher torque approximately at 54.2% of an innerrotor PMFSM. From the comprehensive analysis of both designs it can be conclude that output performance is lower than the SRM and IPMSM design machine. But, it shows that the possibility to increase the design performance by using "deterministic optimization method".