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This paper presents an improved asymmetric half-bridge converter (AHBC) to enhance the output performance of a segmented-stator hybrid-excitation switched reluctance motor (SSHE-SRM) drive. Differences from conventional AHBC include an additional boost capacitor, a power switch, and two diodes added between the dc-bus and the AHBC. The static torque characteristic of a 12/8 SSHE-SRM is briefly analyzed and compared with a conventional SRM (CSRM). Based on the magnetic characteristic, the SSHE-SRM appears to have higher torque production capability. The improved AHBC is employed in order to increase the dc-bus voltage under dynamic operation. Higher voltage can be applied to phase windings and faster excitation and demagnetization currents can be obtained owing to the addition of capacitor voltage. Detailed simulations of the SSHE-SRM drive with the improved AHBC are carried out as well as compared with conventional AHBC. Finally, a 12/8 SSHE-SRM is prototyped. The SSHE-SRM drive based on the improved AHBC and conventional AHBC are experimentally tested. The measured results of static magnetic characteristic and dynamic performances are presented to validate the analysis and effectiveness of the novel converter. [ABSTRACT FROM AUTHOR]

In order to improve the performances of switched reluctance machines (SRMs), such as torque production and power density, combining segmented structure and hybrid-excitation is a proper and useful method. This paper develops a kind of segmented-stator hybrid-excitation SRMs (SS-HESRMs) assisted with permanent magnets (PMs) and investigates on them with different rotor pole numbers. To evaluate the effects of different rotor topologies, the static magnetic characteristics and dynamic performances of two SS-HESRMs with 12/10 and 12/8 poles are briefly presented. Moreover, both SS-HESRMs are compared with two segmented-stator SRMs (SS-SRMs) which have the same basic structure and stator/rotor pole combinations but without PMs. The results reveal that SS-HESRMs produce higher electromagnetic torque than SS-SRMs with the same stator/rotor pole configuration. The 12/10 SS-HESRM exhibits better characteristics, such as higher dynamic average torque, lower torque ripple, and higher power/torque density, than the 12/8 SS-HESRM at low-speed operation. While at high speed, the 12/8 SS-HESRM exhibits better characteristics than 12/10 SS-HESRM. The 12/10 SS-HESRM has stronger starting capability but lower steady-state speed under the same starting condition. Finally, a 12/10 SS-HESRM and a 12/8 SS-HESRM with the same structure and size are prototyped and tested to confirm the predictions. [ABSTRACT FROM PUBLISHER]

Hybrid-excitation switched reluctance motors (HESRMs) have attracted considerable attention for various drive applications due to their simple structure, low cost, and high-torque/power capabilities. This paper comprehensively evaluates and compares a high-torque segmented-stator HESRM drive with a conventional SRM drive in terms of static magnetic and dynamic performances. The stator of the segmented HESRM consists of six individual U-shaped segments; each one has two teeth associated with a permanent magnet (PM) installed between them. The static magnetic characteristics of a segmented HESRM and a conventional SRM, including flux distribution, phase flux linkage, electromagnetic torque, are analyzed and compared. The total fluxes created by the PM and by the excited current are strongly coupled. The details of mathematical model as well as dynamic performances of the segmented HESRM is derived and compared with the conventional SRM. Finally, a segmented HESRM and a conventional SRM of the same size are prototyped for experimental verification. From the comparative study, it is indicated that the segmented HESRM has better characteristics than the conventional SRM, such as less iron consumption, higher static and dynamic average torque production, lower torque ripple, higher power and torque densities, higher efficiency, and stronger starting capability. The measured results of static magnetic characteristic, steady-state and transient performances, and torque–speed characteristic of two SRM drives verify the finite-element analysis, modeling, and corresponding predictions. [ABSTRACT FROM PUBLISHER]

A switched reluctance motor (SRM) with 12/10 poles is investigated in this paper. Compared with the conventional SRMs with single mode, the machine is not only able to be worked as a six-phase motor but also could be used as a three-phase motor, which is thus named multimode SRM (MMSRM). The primary dimensions of the stator and rotor cores are calculated by considering it as a six-phase SRM with long magnetic paths, and the performances of three-phase mode with short magnetic paths are used to test the parameters. The arcs of stator and rotor pole are treated as the optimization objects to minimize torque ripple and copper loss per torque and maximize torque per ampere of the MMSRM. A function is selected to solve the multiobjective problem and the final values of arcs of stator and rotor pole are determined based on the results of finite-element method. The effects of arcs of stator and rotor pole on electromagnetic performances of MMSRM are discussed independently, and a prototype is manufactured to test the simulations. A good agreement between the simulated and measured results verifies the validity of the analytical method and results. [ABSTRACT FROM AUTHOR]

This paper presents a 12/8-pole, three-phase, modular-stator hybrid excitation switched reluctance machine (MSHSRM) assisted with permanent magnets (PMs) as well as its design consideration and performance evaluation. The basic operating principle is illustrated through a specific form of this machine, and the magnetic equivalent circuit model is built and analyzed. Then, the main parameters of the machine are optimized by the finite-element method. The static magnetic characteristics and dynamic performance of this novel machine are simulated and compared with other two SRMs, one is segmented 12/8 SRM without PM, and the other is the conventional 12/8 SRM with unsegmented structure. Finally, two motor prototypes, including one MSHSRM and one conventional SRM of the same size are manufactured. The static magnetic characteristic and dynamic operation of two motor drives are measured to confirm the predictions. The simulation and experimental results indicate that this MSHSRM has higher power and stronger load capacities than the conventional SRM in whole speed range with higher torque/power density and higher torque per ampere. [ABSTRACT FROM AUTHOR]

Modular switched reluctance motors (MSRMs) normally have better characteristics than conventional SRMs (CSRMs) such as lower cost, higher torque production, stronger fault-tolerance, less loss, etc. This paper comprehensively investigates two hybrid-flux MSRMs with the same E-core stator, but different rotor configurations, termed as segmented-rotor MSRM (SR-MSRM) and nonsegmented rotor MSRM (NSR-MSRM), as well as compares with a CSRM. To evaluate the effects of different rotor topologies, the electromagnetic performances of two MSRMs and a CSRM with the same basic dimensions, including machine cost, flux distribution, static flux linkage, and torque, dynamic and transient operation performances are comprehensively analyzed and compared. The results based on finite-element analysis and Simulink indicate that the SR-MSRM has lowest steel consumption, highest torque production, highest power and torque densities, and strongest starting capability. Finally, three motor prototypes, including one SR-MSRM, one NSR-MSRM, and one CSRM are manufactured. The experimental results of static magnetic characteristics, dynamic and transient performances of three SRM drives confirm the predictions. [ABSTRACT FROM AUTHOR]

The mutually coupled dual three-phase switched reluctance motor (DTPSRM) is a new type of special 12/8 SRMs, which possesses high-reliability and fault-tolerant feature. In the past researches, the model, analysis, and fault-tolerant operation were mainly focused on the classical single three- and four-phase SRMs. This paper is mainly to analyze and investigate the fault-tolerant performances of a 12/8-pole mutually coupled DTPSRM drive under various open-circuit operations. First, the static magnetic characteristics of DTPSRM with single- and two-phase excitations are calculated by finite-element analysis. Then, the mathematic model of the DTPSRM drive under open-circuit condition is developed with a combination of state and fault functions. The simulation model of the DTPSRM drive system with a fault-tolerant control strategy is established for dynamic analysis. The faulty characteristics and fault-tolerant performances of the DTPSRM with diverse open circuits are predicted. Finally, a 12/8 DTPSRM is prototyped and an experimental setup is built for verification. The experimental normal results and diverse open-circuit operations and self-starting capability under lack of phases are presented, validating the accuracy of the analysis and simulation as well as fault-tolerant characteristics of the DTPSRM drive system. [ABSTRACT FROM AUTHOR]

The classical switched reluctance motors (SRMs) often suffer from drawbacks such as low power and torque densities, high torque ripple, mutual coupling, etc., which limit their industrial applications. This paper presents the analysis and development of two novel three-phase SRMs with hybrid magnetic paths comprising six E-shaped modular stators and three segmental common rotors, termed as the modular SRMs (MSRMs), for electric vehicle applications. The machine topologies with different winding arrangements are described. The voltage and output power equations are analytically derived, and some design particularities and parameters are discussed. The field distributions and static magnetic characteristics of an MSRM with double coil are analyzed by using 3-D finite-element method. After that, two MSRMs with different winding arrangements, namely a double-coil MSRM and single-coil MSRM, are analyzed and compared to evaluate the distinct features of this novel MSRM, accompanied with a classical three-phase 6/4 SRM. The comparison includes static magnetic characteristics, mass of iron core, normal dynamic, and fault-tolerant performances. It is shown that the double-coil MSRM appears to have better characteristics such as higher torque production capability, lower torque ripple and cost, higher torque and output power densities, and higher reliability and fault tolerance. For experimental verification, laboratory testing of a double-coil MSRM is developed, and the simulated and measured static inductance characteristics and dynamic performances correlate well. [ABSTRACT FROM PUBLISHER]

This study presents a new configuration for dual‐channel switched reluctance motor (DCSRM) called as decoupled DCSRM (DDCSRM), which can be proposed as a suitable candidate for high‐reliability applications. In this new DDCSRM, the two channels could be considered as two synchronously independent 6/4 three‐phase SRMs with no mutual coupling when they are excited simultaneously. The machine topology and magnetic characteristics of flux distribution, static flux linkage and torque by using finite‐element analysis are presented. Then, the mathematic models of the DDCSRM drive under normal and open‐circuit fault operations are proposed. To achieve fault‐tolerant operation, a control strategy of open‐circuit faults for the DDCSRM drive is presented. The key of the fault‐tolerant control strategy is to maintain the rotor speed as the normal motoring operation. The dynamic performances of the DDCSRM drive under normal and open‐circuit fault conditions are analysed by using the control strategy. Finally, an experimental setup for a 12/8 DDCSRM drive system is built for verification. The experimental results at normal and various open‐circuit fault conditions are presented to verify the control strategy of the DDCSRM drive system and the analytical and simulation results. [ABSTRACT FROM AUTHOR]