Finite-control-set model predictive control of axially laminated flux-switching permanent magent machine with extended voltage space vectors

University of Technology Sydney. Faculty of Engineering and Information Technology.The Flux-switching permanent magnet machine (FSPMM) has recently attracted considerable interest for high performance drive applications due to their high torque and high power density features. The laminations of traditional FSPMMs are radially laminated, i.e. steel sheets are laminated perpendicular to the shaft axis. Due to the nonlinear magnetic path, the radial laminations can have serious partial magnetic saturation at the edges/tips of stator teeth or rotor poles. The rated frequency of FSPMMs is usually much higher than traditional rotor-inserted PM machines at a given speed. In this case, the core loss of FSPMMs becomes evident especially beyond the rated speed, which leads to decrease of output power, torque/power density and efficiency. The reluctance motor with axially laminated rotor has received growing interest in recent years. This type of motor can achieve a higher torque density compared with segmented rotors and flux-barrier rotors. In this thesis, an axially laminated flux-switching permanent magnet machine (ALFSPMM) with HiB grain oriented silicon steel stator and rotor cores is proposed. The HiB silicon steel features high permeability and low specific core loss, and as a result, the total power loss of proposed motor is much lower than the conventional FSPMMs. The detailed fabrication procedures are presented. The theoretical characteristics of ALFSPMM are calculated by 2D finite element method (FEM). Experimental measurements of the prototype machine are presented to validate the FEM calculation. On the machine control side, the direct torque control (DTC) is one of the most popular control algorithms. It features simple structure and fast dynamic response. However, the performance of DTC in terms of torque and flux ripples and drive system efficiency is unsatisfactory since the voltage space vector (VSV) is selected heuristically. Recently, the finite-control-set model predictive direct torque control (FCS-MPDTC) has been developed as a simple and promising control technique to overcome these problems. The FCS-MPDTC still suffers from relatively high torque and flux ripples due to the limited number of VSVs. This thesis proposes a novel FCS-MPDTC with an extended set of twenty modulated VSVs, which are formed by eight basic VSVs and twelve extended VSVs by modulating eight basic VSVs with fixed duty ratio. To mitigate the computational burden caused by the increased number of VSVs, a pre-selective scheme is designed for the proposed FCS-MPDTC to filter out the impractical VSVs. The drive system efficiency is also investigated. The theory and simulation are validated by experimental results on the ALFSPMM prototype

Permanent Magnet Assisted Synchronous Reluctance Machine (PMa-SynRM) Design and Performance Analysis for Fan and Pump Applications

One of the major industrial applications of electric machines is driving fans and pumps. According to the pump and fan affinity laws, decreasing the speed of the load can reduce the power consumption on the load significantly. Therefore, a variable speed drive offers reduction in energy consumption of the induction motor driving those types of loads. As an alternative, synchronous machines can be used for this application to get the benefit of higher efficiency. In this work, the performance of an optimized permanent magnet assisted synchronous reluctance machine (PMa-SynRM) with a NEMA standard stator has been studied for fan and pump applications. The effect of using different quantities of the permanent magnet in this machine is studied experimentally. In addition, the performance of the PMa-SynRM is compared with a standard general purpose induction machine for the same loading condition. This work presents the comparison of the energy consumption and performance of the machines under the fan and pump type loads operating on specific typical duty cycles

Study with magnetic property measurement of soft magnetic composite material and its application in electrical machines

This paper reports our study with the magnetic property measurements of soft magnetic composite (SMC) materials under both alternating and rotational magnetic excitations, and development of different electrical machines with SMC cores and three-dimensional magnetic field, such as claw pole and transverse flux motors. Three-dimensional finite element electromagnetic field analysis is conducted for determining some important parameters and optimizing the machine structures. The analysis methods are validated by the experimental results on two SMC motor prototypes

Design and Optimise Synchronous Reluctance Machines in Sensorless Control

This thesis researches the design and fabrication of axially laminated, anisotropic synchronous reluctance rotors with a high saliency ratio and low torque ripple for both three- and five-phase machines. One clear novelty of the research is the first method reported that allows skew to be incorporated in the axially laminated anisotropic (ALA) rotor. The designed rotor is then built with the help of the 3D printing technique which significantly reduces the complexity of the prototyping and fabrication process. The thesis then considers the control necessary including sensorless control schemes for the three- and five-phase synchronous reluctance motors with varying levels of skew. The performance and the effectiveness of the sensorless controllers are verified by experiments for all designed rotors under the three- and five-phase excitation. The three- and five-phase system of the synchronous reluctance motor is first discussed with the stator voltage equations and equivalent circuits. The d-and q-axis inductances are evaluated using finite element analysis. Finite element analysis (FEA) is a common used method in simulating and solving the electrical engineering problems. The FEA shows that for both three- and five-phase motors, the saliency ratio can reach around 10. Further detailed optimization is performed based on the rotor barrier dimensions such as shape, arc length, rib and bridge length, width, and the number of barriers. The final designed rotor in this research is an ALA rotor with 4 poles and 9 layers of magnetic segments. The barrier used is the round-type. The experimental inductances are shown to match the FEA predictions. The method of fabricating an ALA-type rotor with skew is a significant advance in this research. The FEA analysis for both three- and five-phase motor shows that torque ripple can be significantly reduced with the skew process: for instance, the 5.5° skewed rotor and the 9.5° skewed rotor are predicted to offer the best choice for the three- and five-phase stator designs from a parametric study of skew angles. Three skewed rotors are fabricated (5.5 o, 6 o and 9.5o). The experimental results of the torque ripple are compared. For the three-phase case, the rotors with skew shows a good reduction in torque ripple, the 6° skewed rotor performs better than the 5.5° skewed rotor. For the five-phase case, the 9.5° skewed rotor provides the best torque ripple reduction experimentally. The sensorless control is achieved for both three- and five-phase systems. According to the speed demand, the high-frequency injection sensorless control is used when the speed is below 500rpm. To further reduce the transient error, two different sliding mode observer methods are used for three and five-phase systems when the speed demand is above 500rpm. For both three- and five-phase synchronous reluctance motors with non-skewed and skewed rotors, the sensorless control can be successfully implemented. The transient and steady-state errors are all controlled in an acceptable range. By suddenly adding full load at rated and zero speed, the effectiveness of the sensorless control is also verified

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

Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Machinery Program

The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as FreedomCAR (derived from 'Freedom' and 'Cooperative Automotive Research'), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieve the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993 through 2001. The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency. In supporting the development of hybrid propulsion systems, the APEEM effort has enabled the development of technologies that will significantly improve advanced vehicle efficiency, costs, and fuel economy. The APEEM subprogram supports the efforts of the FreedomCAR and Fuel Partnership through a three-phase approach intended to: (1) identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements and then develop the appropriate technical targets for systems, subsystems, and component research and development activities; (2) develop and validate individual subsystems and components, including electric motors, and power electronics; and (3) determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed under this subprogram will help remove technical and cost barriers to enable the development of technology for use in such advanced vehicles as hybrid electric vehicles (HEVs), plug-in HEVs, and fuel-cell-powered automobiles that meet the goals of the Vehicle Technologies Program. A key element in making HEVs practical is providing an affordable electric traction drive system. This will require attaining weight, volume, and cost targets for the power electronics and electrical machines subsystems of the traction drive system. Areas of development include these: (1) novel traction motor designs that result in increased power density and lower cost; (2) inverter technologies involving new topologies to achieve higher efficiency and the ability to accommodate higher-temperature environments; (3) converter concepts that employ means of reducing the component count and integrating functionality to decrease size, weight, and cost; (4) more effective thermal control and packaging technologies; and (5) integrated motor/inverter concepts. The Oak Ridge National Laboratory's (ORNL's) Power Electronics and Electric Machinery Research Center conducts fundamental research, evaluates hardware, and assists in the technical direction of the DOE Vehicle Technologies Program, APEEM subprogram. In this role, ORNL serves on the FreedomCAR Electrical and Electronics Technical Team, evaluates proposals for DOE, and lends its technological expertise to the direction of projects and evaluation of developing technologies

Suurnopeusmoottorin prototyypin tuotteistaminen sarjatuotantoon

Productization is the art of developing a customized product, service or prototype into a standardized marketable and commercialized product. In this thesis a high-speed induction motor prototype is designed for manufacturing. The motor has an output power of 86 kW, rotational speed of 21000 rpm and IEC frame size 160. The motor has a copper coated solid rotor concept, hybrid bearings and a totally enclosed air cooling system. High-speed motor systems provide advantages as improvement of over-all efficiency and reliability in comparison to conventional systems by eliminating the gear box normally used for applications requiring high-speed. In the literature study mechanical restrictions and design considerations due to high rotational speed and centrifugal forces on machine elements are reviewed. Different machine elements are presented as alternatives for high-speed motor components. To construct a profitable product from manufacturing point of view a concurrent engineering philosophy and DFMA method is adopted. The system of hybrid bearings was retained and the bearing support parts design was reconstructed by reconsidering necessity of the tolerances and altering unnecessarily tight tolerances. It was decided that the bearing end shields and the motor frame foot should be incorporated into one part and produced by casting iron in serial production. Prototype evaluation concludes that a standard stator frame can be used and several rotor concepts were evaluated. The potential for reducing the manufacturing costs of the prototype motor are substantial. However, regarding the rotor concepts more development needs to be done to ensure a functional rotor concept.Työn tavoitteena oli tuotteistaa suurnopeussähkömoottorin prototyyppi sarjatuotantoa varten. Lähtökohteena oli 86kW:n suurnopeusmoottori, jonka pyörimisnopeus on 21000 r/min ja IEC runkokoko 160. Moottorilla on kuparipinnoitettu massiiviroottori roottorikonseptina, hybridilaakereita ja ilmajäähdytys. Suurnopeusteknologia mahdollistaa paremman kokonaishyötysuhteen ja kestävämmän järjestelmän poistamalla perinteisesti käytetty vaihteisto suurta pyörimisnopeutta vaativissa sovelluksissa. Suuri pyörimisnopeus ja keskipakovoimien vaikutus suurnopeusmoottorissa aiheuttaa mekaanisia rajoituksia sekä erilliskomponenttien tarvetta. Kirjallisuustutkimuksessa esitellään eri komponenttivaihtoehtoja suurnopeusmoottorin kone-elimistöön. Tuotteistamisprojektissa käytetään rinnakkaissuunnittelun ja DFMA:n periaatteita. Laakerointiosien toleranssien tarkkuus sekä roottorikonsepti on arvioitu uudestaan ja laakerikilvet ovat yhdistetty staattorirungon jalkaan. Standardistaattorirunko sekä alunperäiset hybridilaakerit soveltuvat käytettäväksi sarjatuotantomoottorissa prototyyppimoottorin evaluoinnin mukaan. Moottorin sarjatuotannon kustannukset ovat merkittävästi pienempiä verrattuna prototyyppimoottoriin tuotantokustannuksiin, mutta tarvitaan kuitenkin lisätuotekehitystä saavuttaakseen kannattavan hintalaatusuhteen