Segmented Switched Reluctance Motor Research Articles

Thermal analysis of modified segmented switched reluctance motor with aluminium metal matrix composite fins used in cooling fan applications

Thermal analysis of modified segmented switched reluctance motor with aluminium metal matrix composite fins used in cooling fan applications

A Review on Segmented Switched Reluctance Motors

The switched reluctance motor (SRM) benefits from its magnet-free nature, robust construction, low cost, flexible controls, and the ability to operate in harsh environments such as high temperatures and high pressure. It has received increasing attention for all-electric or multi-electric aircraft systems and electric vehicles (EVs) as compared with permanent magnet synchronous motors (PMSM) and other AC motors in some required high reliability and fault tolerance applications. However, the SRM is prone to considerable wind resistance due to the convex pole structure of the rotor during high-speed rotation, high torque ripple, and also vibration noise. Thus, it is currently a trending topic to develop special SRMs, tailored with high reliability and fault tolerance. Recent research demonstrates several promising feasible solutions to reduce torque ripples and enhance torque density and power factors, including changing topology of SRM, using advanced control methods, as well as different winding configurations. Among these options, the segmented switched reluctance motor (SSRM), as a deformation of the conventional topology, is shown to be capable of effectively optimizing the torque performance. Motivated by this advance, this paper aims to present a comprehensive literature review on the SSRM, first illustrating the development of the topology of the SRM, then providing a description as well as a classification according to the topology of the SSRM. In particular, we focus on the evolution of various kinds of segmental topology and improvement measures. Then, we discuss the performance, advantages, and disadvantages of various types of structures in terms of their electromagnetic aspects and their applications. Eventually, several promising future trends and application prospects of the SSRM are prospected, with the aim of shedding light on further research. In sum, the key contribution of this paper is to provide a valuable basis for detailed analyses of the structure and electromagnetic design of the SSRM that are expected to benefit future research.

Model Predictive Direct Torque Control of Switched Reluctance Motors for Low-Speed Operation

In this paper, a finite-control-set model predictive direct torque control (FCS-MPDTC) method is proposed to reduce the torque ripple of a segmented switched reluctance motor (SSRM) at the low-speed stage. Firstly, the prediction dynamic model is established, and the phase torque can be predicted by detecting phase current and rotor position signals. Then, the principle of power converter and selection of voltage vectors are introduced and presented. Considering torque ripple reduction, flux tracking performance and copper losses reduction, the cost function with phase torque, the amplitude of flux linkage and phase current, is established to select optimal voltage vector to control the power converter. In addition, the torque sharing function (TSF) is employed to distribute total torque to phase torque for further torque ripple reduction. Finally, the direct torque control (DTC) is selected as the comparison method, performance of MPDTC is verified by simulation and experiment results. It can be found that the proposed MPDTC can achieve lower torque ripple and copper losses, and high robustness.

Enhancement of a 12/4 Hybrid-Excitation Switched Reluctance Machine With Both Segmented-Stator and -Rotor

In order to combine the advantages of modularity and hybrid-excitation for motor torque and power density enhancement, this article proposes a 12/4 modular-topology, permanent magnet (PM) assist, hybrid-excitation switched reluctance machine (HESRM) with both segmented-stator and -rotor. The machine topology and basic operating principle are presented. Three key parameters of the machine are optimized for assessment on the torque production <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">.</b> The three-dimensional finite-element analysis is employed to consider the effects of end winding and core saturation. The static magnetic characteristics and dynamic performances are simulated and compared with a 12/4 segmented SRM (SSRM) without PM and a 12/10 segmented-stator HESRM. Two prototypes of the proposed 12/4 HESRM and a 12/10 segmented-stator HESRM with the same size are manufactured and developed for experimental verification. Both results show that the proposed motor can achieve higher dynamic average torque and higher power/torque density at high-speed operation. It also has a stronger starting capability, more rapid response for command changes, as well as better stability and tracking features.

Development of a digital control system for a belt-driven starter generator segmented switched reluctance motor for hybrid electric vehicles

A novel four-phase 16/10 belt-driven starter generator segmented switched reluctance motor has been proposed in a previous work to reduce torque ripple and increase the fault tolerance ability. Based on the previous research, the segmented switched reluctance motor digital control system is designed and presented. The digital control system including a power converter, detection circuits, and protection circuits is introduced in detail. For detection circuits, the half-detection method is employed to decrease the cost of the system. In addition, based on MicroAutoBox DS1401, a rapid control prototype platform is established. With this software system, it is easy to transfer control models and realize real-time control directly. Then, the speed closed closed-loop control for the segmented switched reluctance motor is applied to verify the proposed system. It contains current chopper control at a low speed and angle position control at a high speed. The simulation results are given, including the flux, current, torque, and efficiency range over the entire speed range of the segmented switched reluctance motor. Finally, the experimental results are presented to verify the simulation results and the effectiveness of the system. It can be found that the simulation and experimental results are consistent and acceptable, which means that the proposed digital system can operate naturally and accurately under speed closed loop control. Hence, the proposed digital system has high compatibility and practicability.

Analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in HEV applications

PurposeThe torque ripple and fault-tolerant capability are the two main problems for the switched reluctance motors (SRMs) in applications. The purpose of this paper, therefore, is to propose a novel 16/10 segmented SRM (SSRM) to reduce the torque ripple and improve the fault-tolerant capability in this work.Design/methodology/approachThe stator of the proposed SSRM is composed of exciting and auxiliary stator poles, while the rotor consists of a series of discrete segments. The fault-tolerant and torque ripple characteristics of the proposed SSRM are studied by the finite element analysis (FEA) method. Meanwhile, the characteristics of the SSRM are compared with those of a conventional SRM with 8/6 stator/rotor poles. Finally, FEA and experimental results are provided to validate the static and dynamic characteristics of the proposed SSRM.FindingsIt is found that the proposed novel 16/10 SSRM for the application in the belt-driven starter generator (BSG) possesses these functions: less mutual inductance and high fault-tolerant capability. It is also found that the proposed SSRM provides lower torque ripple and higher output torque. Finally, the experimental results validate that the proposed SSRM runs with lower torque ripple, better output torque and fault-tolerant characteristics, making it an ideal candidate for the BSG and similar systems.Originality/valueThis paper presents the analysis of torque ripple and fault-tolerant capability for a 16/10 segmented switched reluctance motor in hybrid electric vehicles. Using FEA simulation and building a test bench to verify the proposed SSRM’s superiority in both torque ripple and fault-tolerant capability.

Design and Analysis of a Novel Bearingless Segmented Switched Reluctance Motor

A novel bearingless segmented switched reluctance motor (BSSRM) is proposed in this paper to solve the coupling problem of the traditional bearingless switched reluctance motor (BSRM). Different from traditional BSRMs, the proposed BSSRM adopts the double stator and segmented rotor structure, thereby making the motor operate in short flux paths and the magnetic flux path isolated between torque and suspension system. On the basis of introducing the structure and working principle of the BSSRM, the mathematical model of torque and suspension force is deduced. The 2D finite element simulation model is established by the Ansoft software. The influence of structural parameters on torque and suspension system is analyzed, and its electromagnetic characteristic and decoupling characteristic are analyzed. Compared with the double stator bearingless switched reluctance motor (DSBSRM), the BSSRM not only improves the torque and suspension output but also weakens the coupling between torque and suspension system. Finally, the simulation results verify the effectiveness of the BSSRM.

Axial Flux Segmented SRM With a Higher Number of Rotor Segments for Electric Vehicles

Motors for in-wheel electric vehicle application should have high specific torque. In addition, these motors should be rugged, insensitive to vibration, and temperature variation. Therefore, segmented rotor switched reluctance motor (SSRM) could be an attractive alternative to permanent magnet-based motors, which are being used for this application. A limitation of SSRM is that it requires full pitch winding for its operation. Since, in-wheel motors have high diameter to axial length (D/L) ratio, SSRM of these dimensions would be bulky and has high copper loss due to full pitch winding. Hence, in this paper, a novel SSRM with nonoverlapping winding is proposed. This motor is an axial flux SSRM (AFSSRM) with toroidal winding arrangement. It has single-stator, dual-rotor configuration with 12 stator poles and 16 rotor segments on each rotor disc. Design procedure for AFSSRM is developed and a flowchart describing the design algorithm is presented. A finite element method-based simulation is carried out to verify the performance of the proposed AFSSRM. In order to validate the performance of the motor, a prototype is fabricated and experimental results are presented.

Design, Modelling&amp; Simulation of Double Sided Linear Segmented Switched Reluctance Motor

This paper presents the modelling, simulation, and speed control aspects of a 3-phase 6/4 linear switched reluctance motor (LSRM) drives. The Linear switched reluctance motor (LSRM) has never been a popular choice for direct-drive linear motion control system; because it is difficult to control and its output has high torque ripples. It is also due to the fact that the actuator's characteristic is highly dependent on its complex magnetic circuit, which is difficult to model, simulate, and control.Fourier series expression of phase self- inductance under the assumption of negligible mutual effect and various losses is introduced to describe the nonlinear dynamic model of SRM.Simulation results have shown the rationality of model and validity of control strategy. By virtue of MATLAB/SIMULINK, the models of various subsystems are achieved and the modelling procedure is described in detail. Linear segmented switched reluctance motor (LSSRM) using full pitched winding can give 40 - 80% higher torque than conventional SRM for the same frame size. This increase in torque is due to the increase in aligned inductance. However, full pitch winding results in high copper loss, and high active weight. Hence, in this paper, single tooth or concentric winding to replace the full pitch winding of LSSRM is proposed. In order to obtain the same flux paths as with full pitch winding, all the three phases must be excited simultaneously. The torque is produced due to changes in mutual inductance. This method of winding results in reduction of copper, and therefore, weight. With such an arrangement, one phase only requires DC supply.

Coupled Analysis the Segmented SRM Internal Flow Field with Influence of Inhibitor Deformation

The coupled influence between structure and internal flow field will make the pressure oscillation during working process of the solid rocket motor. This coupled effect will bring the dynamic press on the payload and extremely destroyed the payload. For researching the influence of internal flow field by the deformation of inhibitor, the parallel fluid structure interaction method with the large eddy simulation model was used to analyze the solid rocket motor with segments. The results show that the deformation of inhibitor will influence the internal flow field parameter’s distribution and enhance the pressure frequency and amplitude remarkably. The partitioned method could solution the fluid structure interaction problems in the segmented solid rocket motor properly.

Coupled Analysis the Segmented SRM Internal Flow Field with Influence of Inhibitor Deformation

The coupled influence between structure and internal flow field will make the pressure oscillation during working process of the solid rocket motor. This coupled effect will bring the dynamic press on the payload and extremely destroyed the payload. For researching the influence of internal flow field by the deformation of inhibitor, the parallel fluid structure interaction method with the large eddy simulation model was used to analyze the solid rocket motor with segments. The results show that the deformation of inhibitor will influence the internal flow field parameter’s distribution and enhance the pressure frequency and amplitude remarkably. The partitioned method could solution the fluid structure interaction problems in the segmented solid rocket motor properly.