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A MATLAB environment based mathematical model of a 4- phase Switched Reluctance Machine (SRM) with fewer experimental flux linkage and static torque data, with possible measurements using instruments within accuracy and precision, and more extended data with interpolation respectively is presented. The main objective of this research is to investigate the performance of SRM with variable available data used as lookup data in the model of SRM. Firstly, the necessary experimental input data is discussed. Then, these data points are extended for a range of current and rotor positions. Finally, simulations are carried out under these data for the same operating conditions. The accuracy of the results is verified by comparing the simulated current and torque profile of the machine with an experimental current profile. [ABSTRACT FROM AUTHOR]

In this paper, the reluctance torque is utilized for improving the starting and average torques of a conventional brushless wound field synchronous machine (BL-WFSM). The conventional BL-WFSMs have an inherent issue of zero-starting torque. The existing BL topologies use expensive rare-earth permanent magnets (RE-PMs) to improve the starting torque; however, the marker price of RE-PMs fluctuates. Therefore, this paper proposes the use of the reluctance torque for improving the starting and average torques of BL-WFSMs. The winding topology and machine layout are adopted, from recently published work. The suggested approach increases the reluctance effect in BL-WFSM by optimizing the rotor shape. The reluctance effect is optimized, to improve the starting and average torques. The Kriging method and a genetic algorithm are used for the rotor optimization. A two-dimensional finite element analysis confirms the improved starting and average torques based on the increase in the reluctance torque. [ABSTRACT FROM AUTHOR]

Different topologies for brushless wound rotor synchronous machines (BL-WRSMs) have been proposed recently. This paper proposes a new model for the existing sub-harmonically excited BL-WRSM to eliminate the unbalanced radial force presented in the initial model. The initial and proposed models are analyzed using a two-dimensional finite element method. Furthermore, a variable-speed analysis for the BL-WRSM is conducted by altering the stator input current. Finally, a prototype of the proposed model is built and tested at the rated speed, to compare its performance with that of the conventional WRSM. Simulation and experimental results validate the proposed BL-WRSM's operation. [ABSTRACT FROM AUTHOR]

This paper proposes an inverter scheme to generate an additional third-harmonic component alongside the fundamental component of the current. The generated third-harmonic component is used to achieve the brushless operation in a wound field synchronous machine (WFSM). Contrary to the traditional schemes used, i.e., dual inverter, single inverter with extra switches schemes, and single inverter with four transistor legs, the proposed scheme comprises a single inverter with three transistor legs that utilizes a modified third-harmonic injection pulse-width modulation. The brushless operation in WFSM requires two windings on the rotor periphery, i.e., harmonic winding and field winding that are interconnected through a rotating diode bridge rectifier. To maximize the usage of generated third-harmonic component, the selection of pole–slot combinations of the machine is carried out considering the winding factors. The proposed inverter scheme is verified in MATLAB, and a 2-D finite element analysis is used to validate the brushless operation of the machine along with its electromagnetic performance. [ABSTRACT FROM AUTHOR]

This manuscript discusses a novel harmonic current excitation technique for a wound rotor synchronous machine based on control of the time harmonic magneto-motive force (MMF) for brushless operation. Two inverters are used to feed the armature winding in such a way that at a time, one inverter supplies the current to armature winding. The two inverters are 180° phase-shifted. The inverter assignment is based on time-division multiplexing technique to generate continuous armature currents containing reasonable third-harmonic component beside fundamental component. This third-harmonic current component generates pulsating MMF and is induced in the rotor harmonic winding; the induced current is rectified and applied to rotor field winding to generate rotor field. The rotor field interacts with armature fundamental current component for torque generation. Finite element analysis is performed to verify the idea. [ABSTRACT FROM AUTHOR]

This paper studies the effect of permanent magnet shape on the performance and efficiency of coreless axial flux permanent magnet synchronous generator (AFPMSG) for low-speed applications. The objective of this study was to come up with an optimal magnet shape among the studied cases that will lead to the highest value of induced EMF, eventually leading to the better output power of the machine. According to the obtained results, a coreless AFPMSG with a triangular magnet shape has higher induced EMF as compared to trapezoidal or skewed-shaped magnets. Also, a topology with rounded-triangular magnets is analyzed to investigate the effect of the rounded edges on the performance of the generator. 3D-finite element analysis (FEA) is used to analyze and compare the back-EMF and output power of all the investigated coreless AFPMSG topologies. This analysis is carried out using JMAG-Designer 19. 1. [ABSTRACT FROM AUTHOR]