Modeling and control strategies for a variable reluctance direct-drive motor

A high-performance ripple-free dynamic torque controller for a variable-reluctance (VR) motor intended for trajectory tracking in robotic applications is designed. A modeling approach that simplifies the design of the controller is investigated. Model structure and parameter estimation techniques are presented. Different approaches to the overall torque controller design problem are discussed, and the solution adopted is illustrated. A cascade controller structure consisting of a feedforward nonlinear torque compensator, cascaded to a nonlinear flux or current closed-loop controller is considered, and optimization techniques are used for its design. Although developed for a specific commercial motor, the proposed modeling and optimization strategies can be used for other VR motors with magnetically decoupled phases, both rotating and linear. Laboratory experiments for model validation and preliminary simulation results of the overall torque control system are presente

A prototype controller for variable reluctance motors

A three-level cascade structure is proposed for the control of a variable reluctance (VR) motor. In order to deal with the highly nonlinear behavior of VR motors, the controlling system includes two variable-structure controllers for current and velocity loops as well as an intermediate torque-sharing compensator. The intermediate compensator has been designed by means of nonlinear optimization techniques in order to reduce the torque ripple and to get the maximum motor velocity. The proposed controller has been validated through extensive simulation experiments. The architecture of a prototype controller is presented and the actual performance measured on a VR motor is discussed in comparison with simulations. The results show practical feasibility and good performance of the proposed controller, which is also suitable for a very simple and quite inexpensive fully hardware implementatio

Design and experimental verification of a 72/48 switched reluctance motor for low-speed direct-drive mining applications

Typically, a geared drive system is used to connect an induction motor of 1500 rpm with a Raymond Pulverizer of 105 rpm in mining applications. This system suffers from low efficiency and a heavy motor drive. This paper proposes a novel design of a 75 kW, 72/48 switched reluctance motor (SRM) for a low-speed direct-drive as for mining applications. The paper is focused on the design and comparative evaluation of the proposed machine in order to replace a geared drive system whilst providing a high torque low-speed and direct-drive solution. The machine performance is studied and the switching angle configuration of the machine is also optimised. The efficiency of the whole drive system is found to be as high as 90.19%, whereas the geared induction motor drive provides only an efficiency of 59.32% under similar operating conditions. An SRM prototype was built and experimentally tested. Simulation and experimental results show that the drive system has better performance to substitute the induction motor option in mining applications. c 2018 by the authors. Licensee MDPI, Basel, Switzerland

Fuzzy Controller Based DTC of SRM Drive Fed by Common High Side Asymmetric Switch Converter

The switched reluctance motor (SRM) is recently gaining huge popularity in electric vehicle (EV) applications due to its control flexibility, simple structure, lower cost and high efficiency than the synchronous and induction motors. Among all the controllers, the direct torque control (DTC) is the most preferred due to its higher efficiency, lower losses and superior control characteristics. In this paper, a 6/4 pole SRM with fuzzy logic based DTC has been proposed for the EV application along with a converter with reduced switch counts to reduce the torque ripples and enhance the performance of the system under steady and transient state conditions. The proposed system is tested and validated under various scenarios that include load torque and speed variations and compared with the vector control method. From, the investigation it has been found that the proposed technique reduces ripples from the system during all the scenarios with a resultant flux of less than 0.5pu

Drive control and real-time simulation for switched reluctance motor in a fuel cell power system.

Switched Reluctance Motor (SRM) drive is considered as a possible alternative to other conventional variable-speed drives because of several advantages [1], [2]. However, in order for the performance of a switched reluctance motor drive to suit several applications, it has to be tailored through appropriate control. Rotor position sensing is an integral part of SRM control because of the nature of torque production. Sensorless control reduces overall cost and dimension of the drive in addition to improving reliability. In this thesis, an Inductance Model Based Sensorless [8] Switched Reluctance Motor is used to design the drive controller for SRM. A hysteresis current controller and a speed controller were implemented to produce smooth torque and a stable speed for SRM. In addition, the do power supply for the SRM was derived from Fuel Cell Stack rather than from batteries or from utility lines through a front-end diode rectifier. In this research, first, the current controller and the speed controller are developed and connected to the Inductance Based Sensorless SRM model with the Fuel Cell Stack model and an offline simulation using Matlab/Simulink is obtained. A detailed computer model of the SRM control drive connected to the Fuel Cell stack model is developed in which the design of the proposed controller scheme is verified. As a next major step, a Real-Time simulation was obtained for the model using Opal-RT platform, and a comparison between the offline simulation results and real time simulation results is developed. As a final step, the characteristics of the SRM Inductance model, Controller model, and the Fuel Cell stack model are studied in detail, which is required in order to use them in future applications.Dept. of Electrical and Computer Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .S246. Source: Masters Abstracts International, Volume: 43-05, page: 1783. Adviser: X. Chen. Thesis (M.A.Sc.)--University of Windsor (Canada), 2004

Optimum Switching Angle Of Switched Reluctance Motor Using Response Surface Methodology

Switched Reluctance Motor has numerous advantages compared to another electric motor. Simple structure, low-cost production, robustness, and high fault tolerance have been remarkable milestones. Still, the problem of excitation angle at power converter becomes crucial, especially for traction use, requiring higher torque at low speed for starting and acceleration. Therefore, this research emphasized finding the optimum excitation angle at low speed using Response Surface Methodology, a practical application to achieve the highest torque, as indicated by the best speed in the constant torque region. As a result, using Matlab simulation, the adaptive combination of optimum angles reached 2691 rpm quicker than a single excitation angle with 2568 rpm, an increase of 4.79% higher speed using RSM optimization. According to the experimental data, the adaptive combination of optimum angle achieved 2475 rpm better than the single excitation angle reached 2340 rpm, an increase of 5.77% higher speed using the Response Surface Methodology

Synchronous Reluctance Motor Performance Improvement Using MTPA Control Strategy and Five-Level Inverter Topology

An improved vector control method is presented in this study to enhance synchronous reluctance motor (SynRM) performance. The maximum torque per ampere (MTPA) technique has demonstrated good dynamic properties since the torque control is closely tied to the current control. The selection of the control approach is primarily influenced by how the reference current values will be defined. Additionally, a five-level neutral-point-clamped (NPC) inverter replaces the traditional two-level inverter. Only eight voltage vectors can be produced by a two-level inverter, whereas one hundred twenty-five voltage vectors can be generated by a five-level inverter. The goal is to produce an output voltage vector that closely resembles the reference voltage vector in order to ensure a quick response on the one hand and enhance dynamic performance on the other. An exact comparison of the suggested vector control strategy's properties is made once it has been simulated in MATLAB/Simulink. The acquired findings are satisfactory and high performance is attained in terms of response time, torque ripple reduction, and current waveform improvement

A Review of Transverse Flux Machines Topologies and Design

High torque and power density are unique merits of transverse flux machines (TFMs). TFMs are particularly suitable for use in direct-drive systems, that is, those power systems with no gearbox between the electric machine and the prime mover or load. Variable speed wind turbines and in-wheel traction seem to be great-potential applications for TFMs. Nevertheless, the cogging torque, efficiency, power factor and manufacturing of TFMs should still be improved. In this paper, a comprehensive review of TFMs topologies and design is made, dealing with TFM applications, topologies, operation, design and modeling