Evaluation of the magnetization direction effects on ferrite PM brushless fractional machines

Permanent magnets are frequently adopted in small brushless machines for automotive applications. Normally anisotropic ferrites, but some research on bonded magnets is being carried on. Several types of magnetization can be proposed, involving different levels of complexity in the magnetization process. In the paper a comparison between parallel and radial magnetization is described, taking into account on one side the major complexity of the radial process and on the other the small power derating of the paralle

Towards Fully Additively-Manufactured Permanent Magnet Synchronous Machines: Opportunities and Challenges

With the growing interest in electrification and as hybrid and pure electric powertrains are adopted in more applications, electrical machine design is facing challenges in terms of meeting very demanding performance metrics for example high specific power, harsh environments, etc. This provides clear motivation to explore the impact of advanced materials and manufacturing on the performance of electrical machines. This paper provides an overview of additive manufacturing (AM) approaches that can be used for constructing permanent magnet (PM) machines, with a specific focus on additively-manufactured iron core, winding, insulation, PM as well as cooling systems. Since there has only been a few attempts so far to explore AM in electrical machines (especially when it comes to fully additively-manufactured machines), the benefits and challenges of AM have not been comprehensively understood. In this regard, this paper offers a detailed comparison of multiple multi-material AM methods, showing not only the possibility of fully additively-manufactured PM machines but also the potential significant improvements in their mechanical, electromagnetic and thermal properties. The paper will provide a comprehensive discussion of opportunities and challenges of AM in the context of electrical machines

Design of a new non-rare-earth magnetic variable gear for hybrid vehicular propulsion system

This study presents the design of a new non-rare-earth magnetic variable gear (MVG) with 16 electrically controlled gear ratios, which incorporates both the concept of the magnetic gear and the concept of the memory machine. The high-remanence low-coercivity permanent magnet material: namely, the aluminium–nickel–cobalt is adopted to realise the controllable gear ratios. The key is to design the stationary ring newly integrated with magnetising windings in such a way that 16 sets of gear ratios can be achieved so as to fulfil different driving requirements and road conditions. First, the original MVG, the improved MVG and the proposed MVG are discussed. Then, a comprehensive analysis of the proposed MVG is conducted. Consequently, the proposed MVG is extended to electronic-continuously variable transmission for hybrid vehicular propulsion. By using finite element analysis, the electromagnetic performances of three MVGs at various gear ratios are evaluated, hence validating the theoretical design. Moreover, the process of gear-ratio-changing is simulated and analysed. A quantitative comparison among these MVGs is also carried out. Hence, the corresponding validity can be further verified.postprin

Design of systems and components for high-speed electric propulsion systems

This PhD dissertation presents the modelling and design of a novel High Speed (HS) Electric Propulsion System (EPS) for automotive application. In particular, Chapter I presents a comparison among different EPS configurations, which are designed by combining different Permanent Magnet Synchronous Machines (PMSMs) with the corresponding most suitable transmission system; this is done in order to investigate the competitiveness of HS-EPS for automotive applications. Subsequently, the design of a novel ferrite-based HS-PMSM suitable for automotive application is presented in Chapter II. The design has been carried out through a novel multi-parameter analytical design procedure, which has been developed with the aim of achieving a preliminary machine design that considers both design targets and constraints. This preliminary design has been then validated through accurate and extensive finite element analyses, which regard both mechanical and electromagnetic performances. In order to guarantee appropriate coupling between the designed HS-PMSM and vehicle wheels, the design and optimization of a novel coaxial Magnetic Gear Transmission (MaGT) is presented in Chapter III. In particular, a single-stage MaGT is designed at first in accordance with mechanical and magnetic analytical models. However, as far as a very high gear ratio is required (more than 20), the design of a double-stage MaGT has been carried out, which addresses some of the issues arising from the single-stage solution. A comparison in terms of performances and sizes between the two designed MaGTs is thus presented and discussed: the results obtained through the analytical models are validated by means of accurate finite element analyses. Subsequently, a further optimization of the double-stage MaGT has been carried out, which aims at reducing the harmonic content of the magnetic flux density. A comparative study between the two double stage MaGTs is presented and discussed, especially with reference to core losses and temperature distribution, highlighting the improved performances achieved by the optimized configuration

An Improved Sideband Current Harmonic Model of Interior PMSM Drive by Considering Magnetic Saturation and Cross-Coupling Effects

The sideband current harmonics, as parasitic characteristics in permanent-magnet synchronous machine (PMSM) drives with space vector pulsewidth modulation technique, will increase the corresponding electromagnetic loss, torque ripple, vibration, and acoustic noises. Therefore, fast yet accurate evaluation of the resultant sideband current harmonic components is of particular importance during the design stage of the drive system. However, the inevitable magnetic saturation and cross-coupling effects in interior PMSM drives would have a significant impact on the current components, while the existing analytical sideband current harmonic model neglects those effects. This paper introduces a significant improvement on the analytical model by taking into account these effects with corresponding nonlinear factors. Experimental results are carried out to underpin the accuracy improvements of the predictions from the proposed model over the existing analytical one. The proposed model can offer a very detailed and insightful revelation of impacts of the magnetic saturation and cross-coupling effects on the corresponding sideband current harmonics

Design of a new outer-rotor flux-controllable vernier PM in-wheel motor drive for electric vehicle

This paper proposes a new in-wheel motor drive for electric vehicle (EV), which utilizes the outer-rotor topology to directly couple with the tire rims and hence removing the mechanical transmission. The key is to use the vernier structure for obtaining the high-speed to low-speed gear effect and achieving the high output torque at low speed operation. Also, the proposed motor drive adopts the DC field winding for performing the flux weakening control at high speed operation. Thus, this new in-wheel motor drive can smoothly operate within the speed range of 0∼1000rpm at different operation modes for EVs. The motor drive and its three-operation modes for EV operation, as well as the steady-state and transient performances are analyzed by using the time-stepping finite-element-method. © 2011 IEEE.published_or_final_versionThe 2011 International Conference on Electrical Machines and Systems (ICEMS 2011), Beijing, China, 20-23 August 2011. In Proceedings of ICEMS, 2011, p. 1-

A comprehensive analytical mathematic model for permanent-magnet synchronous machines incorporating structural and saturation saliencies

We introduce a new method to model permanent-magnet synchronous machines (PMSMs) with saliencies due to the salient structure and magnetic saturation. We define two parameters to indicate these saliencies, i.e., the structural saliency ratio (Kstr) and the saturation saliency ratio (K sat). To verify the nonlinear model, we tested a real PMSM and numerically simulated it. The nonlinear inductance matrix is deduced and expressed by a nonlinear function regressed from the experimental data. The simulation and experimental results agree well with each other. © 2010 IEEE

Modern Control Approaches for a Wind Energy Conversion System based on a Permanent Magnet Synchronous Generator (PMSG) Fed by a Matrix Converter

This “paper proposes a super-twisting adaptive Control Approaches for a Wind Energy Conversion System Based on a Permanent Magnet Synchronous Generator (PMSG) Fed by a matrix sliding mode for tracking the maximum power point of wind energy conversion systems using permanent magnet synchronous generators (PMSGs). As the adaptive control algorithm employed retains the robustness properties of classical wind energy conversion system control methods when perturbations and parameter uncertainties are present, it can be considered an effective solution; at the same time, it reduces chattering by adjusting gain and generating second-order adaptive control methods. The Egyptian power system (EPS), a three-zone interconnected microgrid (MG), and a single machine linked to the grid are only a few examples of the power systems for which this article introduces the concept of direct adaptive control (SMIB).The goal of our work is to maximize the captured power by solving a multi-input multi-output tracking control problem. In the presence of variations in stator resistance, stator inductance, and magnetic flux linkage, simulation results are presented using real wind speed data and discussed for the proposed controller and four other sliding mode control solutions for the same problem. The proposed controller achieves the best trade-off between tracking performance and chattering reduction among the five considered solutions: compared to a standard sliding mode control algorithm, it reduces chattering by two to five orders of magnitude, and steadystate errors on PMSG rotor velocity by one order of magnitude”. The purpose of this article is to examine wind turbine control system techniques and controller trends related to permanent magnet synchronous generators. The article presents an overview of the most popular control strategies for PMSG wind power conversion systems. There are several kinds of nonlinear sliding modes, such as direct power, backstepping, and predictive currents. To determine the performance of each control under variable wind conditions, a description of each control is presented, followed by a simulation performed in MATLAB /Simulink. This simulation evaluates the performance of each control in terms of reference tracking, response times, stability, and signal quality. Finally, this work was concluded with a comparison of the four controls to gain a better understanding of their effects. “Moreover, it reduces the above-mentioned steady-state error by four orders of magnitude compared to a previously-proposed linear quadratic regulator based integral sliding mode control law.  A dynamic model is simulated under both variable step and random wind speeds using the DEV-C++ software, and the results are plotted using MATLAB. The obtained results demonstrate the robustness of the proposed controller in spite of the presence of different uncertainties when compared to the classical direct torque control technique