Computer-based automated test measurement system for determining magnetization characteristics of switched reluctance motors

©2001 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.This paper describes a fully automated method of measuring the magnetization characteristics (flux linkage versus current and position) of switched-reluctance (SR) motors. The measuring scheme was developed using a graphical programming environment (LabVIEW), a data acquisition card, and external interface hardware. The graphical programming method allows a high degree of software modularity and provides the features needed for sensor zero adjustment, data acquisition and analysis, and automated presentation of results. Furthermore, the experimental setup described in this paper can be used to obtain the magnetization characteristics of other electromechanical devices. Experimentally measured results from a test SR motor using the scheme are presented in the paper.Adrian David Cheok and Nesimi Ertugru

Indirect angle estimation in switched reluctance motor drives using fuzzy logic based motor model

Copyright © 2000 IEEEIn this paper, a novel rotor position estimation scheme is described that was developed to overcome the drawbacks of the previous sensorless techniques, which were proposed for switched reluctance (SR) motor drives. It is based on fuzzy-logic, and does not require complex mathematical models or large look up tables. The scheme was implemented by using a digital signal processor. The real-time experimental results given in this paper show that the position estimation method proposed can provide accurate and continual position data over a wide range of speeds (zero/low/high), and can also function accurately at different operating conditions (chopping/single pulse mode and steady state/transient operation).Nesimi Ertugrul and Adrian D. Cheo

Dynamic measurement of magnetic characteristics of switched reluctance motor

Introduction. Switched reluctance motor (SRM) is a type of electric motor featuring nonlinear magnetic characteristics. The flux linkage or inductance profile of SRM is usually required for the purpose of high control performance, and can be normally obtained through conventional static test by using DC or AC method when the rotor is locked. Problem. However, it is not practical to use the conventional method of measurement when the specific apparatus for locking the rotor is unavailable. Besides, due to the magnetic nonlinearity of SRM, the saturation effect makes it difficult to obtain the saturated magnetic characteristics, and the conventional static AC test fails to address this problem. Novelty. In this paper, a dynamic measurement method of the magnetization curves of SRM is proposed which allows the measurement take place while the motor is running with load. Methodology. Based on the conventional static AC test, the proposed measurement handles the saturation problem successfully by introducing a DC offset in the high frequency AC voltage. Phase inductance with different rotor positions and currents can be obtained by analyzing simple equivalent circuit. Practical value. Simulation is conducted in MATLAB/Simulink environment and the results have verified that the proposed dynamic measurement can effectively obtain the magnetic characteristics of SRM.Вступ. Вентильний реактивний двигун (ВРД) є типом електродвигуна з нелінійними магнітними характеристиками. Профіль потокозчеплення або індуктивності ВРД зазвичай потрібний для забезпечення високої ефективності управління і зазвичай може бути отриманий за допомогою звичайних статичних випробувань з використанням постійного або змінного струму, коли ротор заблокований. Проблема. Однак недоцільно використовувати традиційний метод вимірювання, коли відсутній спеціальний пристрій для блокування ротора. Крім того, через магнітну нелінійність ВРД ефект насичення ускладнює отримання насичених магнітних характеристик, і звичайне статичне випробування змінним струмом не вирішує цю проблему. Новизна. У цій роботі пропонується метод динамічного вимірювання кривих намагнічування ВРМ, який дозволяє проводити вимірювання під час роботи двигуна з навантаженням. Методологія Пропонований вимір, заснований на звичайному статичному випробуванні змінним струмом, успішно вирішує проблему насичення за рахунок введення зміщення постійного струму у високочастотну змінну напругу. Фазна індуктивність при різних положеннях ротора та струмів може бути отримана шляхом аналізу простої еквівалентної схеми. Практична цінність. Моделювання проводилося у MATLAB/Simulink, і результати підтвердили, що пропонованим динамічним вимірюванням можливо ефективно отримати магнітні характеристики ВРД

Dynamic measurement of magnetic characteristics of switched reluctance motor

Introduction. Switched reluctance motor (SRM) is a type of electric motor featuring nonlinear magnetic characteristics. The flux linkage or inductance profile of SRM is usually required for the purpose of high control performance, and can be normally obtained through conventional static test by using DC or AC method when the rotor is locked. Problem. However, it is not practical to use the conventional method of measurement when the specific apparatus for locking the rotor is unavailable. Besides, due to the magnetic nonlinearity of SRM, the saturation effect makes it difficult to obtain the saturated magnetic characteristics, and the conventional static AC test fails to address this problem. Novelty. In this paper, a dynamic measurement method of the magnetization curves of SRM is proposed which allows the measurement take place while the motor is running with load. Methodology. Based on the conventional static AC test, the proposed measurement handles the saturation problem successfully by introducing a DC offset in the high frequency AC voltage. Phase inductance with different rotor positions and currents can be obtained by analyzing simple equivalent circuit. Practical value. Simulation is conducted in MATLAB/Simulink environment and the results have verified that the proposed dynamic measurement can effectively obtain the magnetic characteristics of SRM.Вступ. Вентильний реактивний двигун (ВРД) є типом електродвигуна з нелінійними магнітними характеристиками. Профіль потокозчеплення або індуктивності ВРД зазвичай потрібний для забезпечення високої ефективності управління і зазвичай може бути отриманий за допомогою звичайних статичних випробувань з використанням постійного або змінного струму, коли ротор заблокований. Проблема. Однак недоцільно використовувати традиційний метод вимірювання, коли відсутній спеціальний пристрій для блокування ротора. Крім того, через магнітну нелінійність ВРД ефект насичення ускладнює отримання насичених магнітних характеристик, і звичайне статичне випробування змінним струмом не вирішує цю проблему. Новизна. У цій роботі пропонується метод динамічного вимірювання кривих намагнічування ВРМ, який дозволяє проводити вимірювання під час роботи двигуна з навантаженням. Методологія Пропонований вимір, заснований на звичайному статичному випробуванні змінним струмом, успішно вирішує проблему насичення за рахунок введення зміщення постійного струму у високочастотну змінну напругу. Фазна індуктивність при різних положеннях ротора та струмів може бути отримана шляхом аналізу простої еквівалентної схеми. Практична цінність. Моделювання проводилося у MATLAB/Simulink, і результати підтвердили, що пропонованим динамічним вимірюванням можливо ефективно отримати магнітні характеристики ВРД

Computationally Efficient Optimization of a Five-Phase Flux-Switching PM Machine Under Different Operating Conditions

This paper investigates the comparative design optimizations of a five-phase outer-rotor flux-switching permanent magnet (FSPM) machine for in-wheel traction applications. To improve the comprehensive performance of the motor, two kinds of large-scale design optimizations under different operating conditions are performed and compared, including the traditional optimization performed at the rated operating point and the optimization targeting the whole driving cycles. Three driving cycles are taken into account, namely, the urban dynamometer driving schedule (UDDS), the highway fuel economy driving schedule (HWFET), and the combined UDDS/HWFET, representing the city, highway, and combined city/highway driving, respectively. Meanwhile, the computationally efficient finite-element analysis (CE-FEA) method, the cyclic representative operating points extraction technique, as well as the response surface methodology (in order to minimize the number of experiments when establishing the inverse machine model), are presented to reduce the computational effort and cost. From the results and discussion, it will be found that the optimization results against different operating conditions exhibit distinct characteristics in terms of geometry, efficiency, and energy loss distributions. For the traditional optimization performed at the rated operating point, the optimal design tends to reduce copper losses but suffer from high core losses; for UDDS, the optimal design tends to minimize both copper losses and PM eddy-current losses in the low-speed region; for HWFET, the optimal design tends to minimize core losses in the high-speed region; for the combined UDDS/HWFET, the optimal design tends to balance/compromise the loss components in both the low-speed and high-speed regions. Furthermore, the advantages of the adopted optimization methodologies versus the traditional procedure are highlighted

Design and Construction Modifications of Switched Reluctance Machines

Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system

Model predictive current control of switched reluctance motor with inductance auto-calibration

The thesis is composed of three papers, which investigate the application of Model Predictive Controller (MPC) for current control of Switched Reluctance Motor (SRM). Since the conventional hysteresis current control method is not suitable for high power SRM drive system with low inductance and limited switching frequency, MPC is a promising alternative approach for this application. The proposed MPC can cope with the measurement noise as well as uncertainties within the machine inductance profile. In the first paper, a MPC current control method for Double-Stator Switched Reluctance Motor (DSSRM) drives is presented. A direct adaptive estimator is incorporated to follow the inductance variations in a DSSRM. In the second paper, the Linear Quadratic (LQ) form and dynamic programming recursion for MPC are analyzed, afterwards the unconstrained MPC solution for stochastic SRM model is derived. The Kalman filter is employed to reduce the variance of measurement noises. Based on Recursive Linear-Square (RLS) estimation, the inductance profile is calibrated dynamically. In the third paper, a simplified recursive MPC current control algorithm for SRM is applied for embedded implementation. A novel auto-calibration method for inductance surface estimation is developed to improve current control performance of SRM drive in statistic terms. --Abstract, page iv

Multiple Objective Co-Optimization of Switched Reluctance Machine Design and Control

This dissertation includes a review of various motor types, a motivation for selecting the switched reluctance motor (SRM) as a focus of this work, a review of SRM design and control optimization methods in literature, a proposed co-optimization approach, and empirical evaluations to validate the models and proposed co-optimization methods. The switched reluctance motor (SRM) was chosen as a focus of research based on its low cost, easy manufacturability, moderate performance and efficiency, and its potential for improvement through advanced design and control optimization. After a review of SRM design and control optimization methods in the literature, it was found that co-optimization of both SRM design and controls is not common, and key areas for improvement in methods for optimizing SRM design and control were identified. Among many things, this includes the need for computationally efficient transient models with the accuracy of FEA simulations and the need for co-optimization of both machine geometry and control methods throughout the entire operation range with multiple objectives such as torque ripple, efficiency, etc. A modeling and optimization framework with multiple stages is proposed that includes robust transient simulators that use mappings from FEA in order to optimize SRM geometry, windings, and control conditions throughout the entire operation region with multiple objectives. These unique methods include the use of particle swarm optimization to determine current profiles for low to moderate speeds and other optimization methods to determine optimal control conditions throughout the entire operation range with consideration of various characteristics and boundary conditions such as voltage and current constraints. This multi-stage optimization process includes down-selections in two previous stages based on performance and operational characteristics at zero and maximum speed. Co-optimization of SRM design and control conditions is demonstrated as a final design is selected based on a fitness function evaluating various operational characteristics including torque ripple and efficiency throughout the torque-speed operation range. The final design was scaled, fabricated, and tested to demonstrate the viability of the proposed framework and co-optimization method. Accuracy of the models was confirmed by comparing simulated and empirical results. Test results from operation at various torques and speeds demonstrates the effectiveness of the optimization approach throughout the entire operating range. Furthermore, test results confirm the feasibility of the proposed torque ripple minimization and efficiency maximization control schemes. A key benefit of the overall proposed approach is that a wide range of machine design parameters and control conditions can be swept, and based on the needs of an application, the designer can select the appropriate geometry, winding, and control approach based on various performance functions that consider torque ripple, efficiency, and other metrics