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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Mon, 04 Nov 2024 08:54:37 GMT2024-11-04T08:54:37ZMaximum Torque Per Ampere Strategy for a Biharmonic Five-phase Synchronous Machine
http://hdl.handle.net/10985/11323
Maximum Torque Per Ampere Strategy for a Biharmonic Five-phase Synchronous Machine
ZAHR, Hussein; ASLAN, Bassel; SEMAIL, Eric; SCUILLER, Franck
The paper studies the impact of first and third current-harmonic repartition in a five-phase Permanent Magnet machine whose Electromotive Forces (emfs) have first and third harmonics of the same amplitude. With a five-phase machine, it is possible for the torque production to achieve independent controls of the first and third harmonics of currents by using a vector control in each one of the two characteristic orthogonal sub-spaces of the machine. The same torque quality as obtained with a three-phase machine with sinusoidal emf can be thus obtained with a non-sinusoidal emf and with one more supplementary degree of freedom for the control. Based on the Maximum Torque Per Ampere (MTPA) strategy used for three-phase machines, a comparison of the obtained torque/speed characteristics of the machine is achieved using either one or two harmonics. The voltage limits imposed by the Voltage Source Inverter and two different values of the maximum allowed current densities are taken into account for obtaining the optimum repartition between first and third harmonics of currents: it appears that at first, from the point of view of efficiency, the MTPA is not optimal except for low speeds and secondly that the repartition of currents is not trivial and depends for example on the considered maximum current densities.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/113232016-01-01T00:00:00ZZAHR, HusseinASLAN, BasselSEMAIL, EricSCUILLER, FranckThe paper studies the impact of first and third current-harmonic repartition in a five-phase Permanent Magnet machine whose Electromotive Forces (emfs) have first and third harmonics of the same amplitude. With a five-phase machine, it is possible for the torque production to achieve independent controls of the first and third harmonics of currents by using a vector control in each one of the two characteristic orthogonal sub-spaces of the machine. The same torque quality as obtained with a three-phase machine with sinusoidal emf can be thus obtained with a non-sinusoidal emf and with one more supplementary degree of freedom for the control. Based on the Maximum Torque Per Ampere (MTPA) strategy used for three-phase machines, a comparison of the obtained torque/speed characteristics of the machine is achieved using either one or two harmonics. The voltage limits imposed by the Voltage Source Inverter and two different values of the maximum allowed current densities are taken into account for obtaining the optimum repartition between first and third harmonics of currents: it appears that at first, from the point of view of efficiency, the MTPA is not optimal except for low speeds and secondly that the repartition of currents is not trivial and depends for example on the considered maximum current densities.Multi-criteria based design approach of multiphase permanent magnet low speed synchronous machines
http://hdl.handle.net/10985/6957
Multi-criteria based design approach of multiphase permanent magnet low speed synchronous machines
CHARPENTIER, Jean-Frederic; LETELLIER, Paul; SEMAIL, Eric; SCUILLER, Franck
A design methodology dedicated to multi-phase permanent magnet synchronous machines (PMSMs) supplied by pulse width modulation voltage source inverters (PWM VSIs) is presented. First, opportunities for increasing torque density using the harmonics are considered. The specific constraints caused by the PWM supply of multi-phase machines are also taken into account during the design phase. All the defined constraints are expressed in a simple manner by using a multi-machine modelling of the multi-phase machines. This multi-machine design is then applied to meet the specifications of a marine propeller: verifying simultaneously four design constraints, an initial 60-pole three-phase machine is converted into a 58-pole five-phase machine without changing the geometry and the active volume (iron, copper and magnet). First, a specific fractional-slot winding, which yields to good characteristics for PWM supply and winding factors, is chosen. Then, using this winding, the magnet layer is designed to improve the flux focussing. According to analytical and numerical calculations, the five-phase machine provides a higher torque (about 15%) and less pulsating torque (71% lower) than the initial three-phase machine with the same copper losses.
Version éditeur disponible à cette adresse : http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4797497&isnumber=4797494
Thu, 01 Jan 2009 00:00:00 GMThttp://hdl.handle.net/10985/69572009-01-01T00:00:00ZCHARPENTIER, Jean-FredericLETELLIER, PaulSEMAIL, EricSCUILLER, FranckA design methodology dedicated to multi-phase permanent magnet synchronous machines (PMSMs) supplied by pulse width modulation voltage source inverters (PWM VSIs) is presented. First, opportunities for increasing torque density using the harmonics are considered. The specific constraints caused by the PWM supply of multi-phase machines are also taken into account during the design phase. All the defined constraints are expressed in a simple manner by using a multi-machine modelling of the multi-phase machines. This multi-machine design is then applied to meet the specifications of a marine propeller: verifying simultaneously four design constraints, an initial 60-pole three-phase machine is converted into a 58-pole five-phase machine without changing the geometry and the active volume (iron, copper and magnet). First, a specific fractional-slot winding, which yields to good characteristics for PWM supply and winding factors, is chosen. Then, using this winding, the magnet layer is designed to improve the flux focussing. According to analytical and numerical calculations, the five-phase machine provides a higher torque (about 15%) and less pulsating torque (71% lower) than the initial three-phase machine with the same copper losses.Inductances and back-emf harmonics influence on the Torque/Speed characteristic of five-phase SPM machine
http://hdl.handle.net/10985/10306
Inductances and back-emf harmonics influence on the Torque/Speed characteristic of five-phase SPM machine
SEMAIL, Eric; SCUILLER, Franck
In this paper, the study of torque/speed characteristic for five-phase Surface-mounted Permanent Magnet (SPM) machine is carried out. With considering several hypothesis (linear magnetic modelling, only first and third harmonic terms in the back-emf and current spectrums), an optimization problem that aims to maximize the torque for given maximum voltage and RMS current is formulated: the optimal torque sharing among the two virtual machines (the two dq-axis subspaces) that represent the real five-phase machine is thus calculated for any mechanical speed. For an inverter and a DC voltage sized with only considering the first harmonic of back-emf and current, the problem is solved with changing the ratio between the two virtual machine back-emfs and changing the ratio between the two virtual machine inductances. The results are examined by introducing particular speed points.
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10985/103062014-01-01T00:00:00ZSEMAIL, EricSCUILLER, FranckIn this paper, the study of torque/speed characteristic for five-phase Surface-mounted Permanent Magnet (SPM) machine is carried out. With considering several hypothesis (linear magnetic modelling, only first and third harmonic terms in the back-emf and current spectrums), an optimization problem that aims to maximize the torque for given maximum voltage and RMS current is formulated: the optimal torque sharing among the two virtual machines (the two dq-axis subspaces) that represent the real five-phase machine is thus calculated for any mechanical speed. For an inverter and a DC voltage sized with only considering the first harmonic of back-emf and current, the problem is solved with changing the ratio between the two virtual machine back-emfs and changing the ratio between the two virtual machine inductances. The results are examined by introducing particular speed points.Magnet Shape Optimization to Reduce Pulsating Torque for a Five-Phase Permanent-Magnet Low-Speed Machine
http://hdl.handle.net/10985/8440
Magnet Shape Optimization to Reduce Pulsating Torque for a Five-Phase Permanent-Magnet Low-Speed Machine
SCUILLER, Franck
Five-phase Surface-Mounted Permanent Magnet (SMPM) machines can inherently produce a smooth electromagnetic torque which can be increased when using third harmonic current injection. To really take advantage of these characteristics, the rotor magnets can be shaped in order to obtain a back-emf with large third harmonic term. This is the scope of the paper. For the design specifications of a low speed marine propulsion machine, the following objective must be achieved: to significantly mitigate the pulsating torque without reducing the average torque bearing in mind the solution where the rotor is made with full pole-pitch magnets. An analytical field computation, called equivalent coil method, is developed in order to quicly explore the magnet geometries. Thus a procedure to optimize small trapezoid notches at the surface of the pole magnets is performed. Referring to the classical fully pole-pitch magnet shape, the solution found allows a substantial reduction of the pulsating torque without reducing the torque density. Furthermore, with regard to an equivalent three-phase machine, for the same copper losses, the average torque of the optimized five-phase machine can be potentially higher if the third harmonic current injection is implemented.
The author would like to thank S. Djebarri from the Research Institute of Naval Academy for his help with computing the machines with FEA program FEMM and F. Byrne from the French Naval Academy for her English proofreading
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10985/84402014-01-01T00:00:00ZSCUILLER, FranckFive-phase Surface-Mounted Permanent Magnet (SMPM) machines can inherently produce a smooth electromagnetic torque which can be increased when using third harmonic current injection. To really take advantage of these characteristics, the rotor magnets can be shaped in order to obtain a back-emf with large third harmonic term. This is the scope of the paper. For the design specifications of a low speed marine propulsion machine, the following objective must be achieved: to significantly mitigate the pulsating torque without reducing the average torque bearing in mind the solution where the rotor is made with full pole-pitch magnets. An analytical field computation, called equivalent coil method, is developed in order to quicly explore the magnet geometries. Thus a procedure to optimize small trapezoid notches at the surface of the pole magnets is performed. Referring to the classical fully pole-pitch magnet shape, the solution found allows a substantial reduction of the pulsating torque without reducing the torque density. Furthermore, with regard to an equivalent three-phase machine, for the same copper losses, the average torque of the optimized five-phase machine can be potentially higher if the third harmonic current injection is implemented.Five-phase SPM machine with electronic pole changing effect for marine propulsion
http://hdl.handle.net/10985/11662
Five-phase SPM machine with electronic pole changing effect for marine propulsion
ZAHR, Hussein; SEMAIL, Eric; SCUILLER, Franck
In this paper, the possibility of designing a five-phase Surface-mounted Permanent Magnet (SPM) machine with 20 slots and 8 poles for a low power marine propulsion system is examined. Due to its particular winding and surface magnet design, the machine inherently offers an electronic pole changing effect from 3×4 pole pairs at low speed to 4 pole pairs at high speed. At high speed, in the constant power range, according to Finite Element Analysis, the Maximum Torque Per Ampere strategy appears not to be the right solution to minimize the whole machine losses (copper, iron and magnets). In particular, a strategy that favors the 4-pole rotating field at high speed allows to mitigate the magnet losses, thus limiting the risk of magnet overheating.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/116622016-01-01T00:00:00ZZAHR, HusseinSEMAIL, EricSCUILLER, FranckIn this paper, the possibility of designing a five-phase Surface-mounted Permanent Magnet (SPM) machine with 20 slots and 8 poles for a low power marine propulsion system is examined. Due to its particular winding and surface magnet design, the machine inherently offers an electronic pole changing effect from 3×4 pole pairs at low speed to 4 pole pairs at high speed. At high speed, in the constant power range, according to Finite Element Analysis, the Maximum Torque Per Ampere strategy appears not to be the right solution to minimize the whole machine losses (copper, iron and magnets). In particular, a strategy that favors the 4-pole rotating field at high speed allows to mitigate the magnet losses, thus limiting the risk of magnet overheating.Comparizon of Conventional and Unconventional 5-phase PM Motor Structures for Naval Applications
http://hdl.handle.net/10985/7378
Comparizon of Conventional and Unconventional 5-phase PM Motor Structures for Naval Applications
SEMAIL, Eric; CHARPENTIER, Jean-Frederic; SCUILLER, Franck; CLENET, Stephane
Multi-phase motors are widely used in marine propulsion. In this paper, a Multi-machine modeling of Surface Mounted PM motors is presented and applied to a 5-phase one. The latter is proved to be equivalent to a set of two-phase fictitious machines each ones being characterized by a set of specific harmonic rank. A simple control consists in supplying each fictitious machine by a current which contains only one harmonic. A five phase machine is then supplied by currents with only both first and third harmonics. Considering this kind of control, it is proved that for given stator resistance and average torque the Joule losses and the torque ripple are minimized if a simple criterion on the harmonics of electromotive force at constant speed is fullfilled. Different structures of rotor are then compared to examine numerically which improvements can be practically obtained
Thu, 01 Jan 2004 00:00:00 GMThttp://hdl.handle.net/10985/73782004-01-01T00:00:00ZSEMAIL, EricCHARPENTIER, Jean-FredericSCUILLER, FranckCLENET, StephaneMulti-phase motors are widely used in marine propulsion. In this paper, a Multi-machine modeling of Surface Mounted PM motors is presented and applied to a 5-phase one. The latter is proved to be equivalent to a set of two-phase fictitious machines each ones being characterized by a set of specific harmonic rank. A simple control consists in supplying each fictitious machine by a current which contains only one harmonic. A five phase machine is then supplied by currents with only both first and third harmonics. Considering this kind of control, it is proved that for given stator resistance and average torque the Joule losses and the torque ripple are minimized if a simple criterion on the harmonics of electromotive force at constant speed is fullfilled. Different structures of rotor are then compared to examine numerically which improvements can be practically obtainedComparison of Optimized Control Strategies of a High-Speed Traction Machine with Five Phases and Bi-Harmonic Electromotive Force
http://hdl.handle.net/10985/11435
Comparison of Optimized Control Strategies of a High-Speed Traction Machine with Five Phases and Bi-Harmonic Electromotive Force
ZAHR, Hussein; GONG, Jinlin; SEMAIL, Eric; SCUILLER, Franck
The purpose of the paper is to present the potentialities in terms of the control of a new kind of PM synchronous machine. With five phases and electromotive forces whose first (E1) and third (E3) harmonics are of similar amplitude, the studied machine, so-called bi-harmonic, has properties that are interesting for traction machine payload. With three-phase machines, supplied by a mono-harmonic sinusoidal current, the weak number of freedom degrees limits the strategy of control for traction machines especially when voltage saturation occurs at high speeds. As the torque is managed for three-phase machines by a current with only one harmonic, flux weakening is necessary to increase speed when the voltage limitation is reached. The studied five-phase machine, thanks to the increase in the number of freedom degrees for control, aims to alleviate this fact. In his paper, three optimized control strategies are compared in terms of efficiency and associated torque/speed characteristics. These strategies take into account numerous constraints either from the supply (with limited voltage) or from the machine (with limited current densities and maximum acceptable copper, iron and permanent magnet losses). The obtained results prove the wide potentialities of such a kind of five-phase bi-harmonic machine in terms of control under constraints. It is thus shown that the classical Maximum Torque Per Ampere (MTPA) strategy developed for the three-phase machine is clearly not satisfying on the whole range of speed because of the presence of iron losses whose values can no more be neglected at high speeds. Two other strategies have been then proposed to be able to manage the compromises, at high speeds, between the high values of torque and efficiency under the constraints of admissible total losses either in the rotor or in the stator.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/114352016-01-01T00:00:00ZZAHR, HusseinGONG, JinlinSEMAIL, EricSCUILLER, FranckThe purpose of the paper is to present the potentialities in terms of the control of a new kind of PM synchronous machine. With five phases and electromotive forces whose first (E1) and third (E3) harmonics are of similar amplitude, the studied machine, so-called bi-harmonic, has properties that are interesting for traction machine payload. With three-phase machines, supplied by a mono-harmonic sinusoidal current, the weak number of freedom degrees limits the strategy of control for traction machines especially when voltage saturation occurs at high speeds. As the torque is managed for three-phase machines by a current with only one harmonic, flux weakening is necessary to increase speed when the voltage limitation is reached. The studied five-phase machine, thanks to the increase in the number of freedom degrees for control, aims to alleviate this fact. In his paper, three optimized control strategies are compared in terms of efficiency and associated torque/speed characteristics. These strategies take into account numerous constraints either from the supply (with limited voltage) or from the machine (with limited current densities and maximum acceptable copper, iron and permanent magnet losses). The obtained results prove the wide potentialities of such a kind of five-phase bi-harmonic machine in terms of control under constraints. It is thus shown that the classical Maximum Torque Per Ampere (MTPA) strategy developed for the three-phase machine is clearly not satisfying on the whole range of speed because of the presence of iron losses whose values can no more be neglected at high speeds. Two other strategies have been then proposed to be able to manage the compromises, at high speeds, between the high values of torque and efficiency under the constraints of admissible total losses either in the rotor or in the stator.Design Considerations of Five-Phase Machine with Double p/3p Polarity
http://hdl.handle.net/10985/13423
Design Considerations of Five-Phase Machine with Double p/3p Polarity
GONG, Jinlin; ZAHR, Hussein; TRABELSI, Mohamed; ASLAN, Bassel; SEMAIL, Eric; SCUILLER, Franck
In the context of traction drives with required torque transient capabilities and a classically wide flux weakening speed range, this paper gives design considerations of a particular Double-Polarity (DP) five-phase machine. Beyond its intrinsic fault tolerance due its five phases, its specificity is the ability to develop torques of comparable values under three kinds of supply: with only first, third or both first and third sinusoidal currents. This property, due to first (E1) and third (E3) harmonic electromotive forces (emf) of comparable values, gives more degrees of freedom for the control of the machine. Unlike three-phase sinusoidal machine, flux weakening is no more the unique solution when maximum voltage is reached. Thanks to the extra degrees of freedom in this kind of machines, more possibilities for the control of the torque and current supply can be applied. At first, elements for the choice of slots/poles combination of such DP machines are given. Then, in case of an Interior Permanent Magnet Synchronous Machine (IPMSM), possible adaptations of the rotor are proposed in order to bring the double p/3p polarity property. The last design criterion considered is the level of eddy-current losses, important at high frequencies. For proof of the concept effectiveness, a prototype with a five-phase fractional-slot concentrated winding of 40 slots and 16/48 poles is presented with results from experimental set-up and Finite Element modeling. A comparison with equivalent no-fault-tolerant three-phase 24 slots /16 poles machines is also carried out.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/134232018-01-01T00:00:00ZGONG, JinlinZAHR, HusseinTRABELSI, MohamedASLAN, BasselSEMAIL, EricSCUILLER, FranckIn the context of traction drives with required torque transient capabilities and a classically wide flux weakening speed range, this paper gives design considerations of a particular Double-Polarity (DP) five-phase machine. Beyond its intrinsic fault tolerance due its five phases, its specificity is the ability to develop torques of comparable values under three kinds of supply: with only first, third or both first and third sinusoidal currents. This property, due to first (E1) and third (E3) harmonic electromotive forces (emf) of comparable values, gives more degrees of freedom for the control of the machine. Unlike three-phase sinusoidal machine, flux weakening is no more the unique solution when maximum voltage is reached. Thanks to the extra degrees of freedom in this kind of machines, more possibilities for the control of the torque and current supply can be applied. At first, elements for the choice of slots/poles combination of such DP machines are given. Then, in case of an Interior Permanent Magnet Synchronous Machine (IPMSM), possible adaptations of the rotor are proposed in order to bring the double p/3p polarity property. The last design criterion considered is the level of eddy-current losses, important at high frequencies. For proof of the concept effectiveness, a prototype with a five-phase fractional-slot concentrated winding of 40 slots and 16/48 poles is presented with results from experimental set-up and Finite Element modeling. A comparison with equivalent no-fault-tolerant three-phase 24 slots /16 poles machines is also carried out.Effect of Rotor Bar Number on Performance of Five-Phase Induction Machine for Traction
http://hdl.handle.net/10985/13800
Effect of Rotor Bar Number on Performance of Five-Phase Induction Machine for Traction
MEKAHLIA, Abdelhak; HAMITI, Tahar; BENLAMINE, Raouf; SEMAIL, Eric; SCUILLER, Franck
The paper investigates the effect of the bar number on the performances of a five-phase squirrel-cage induction machine with fractional-slot tooth concentrated winding. With a same stator, five different rotor bar numbers are chosen and the rotor magnetic circuits are designed using an analytical approach. Then, a finite-element analysis is done under two different supply conditions: fundamental currents and third harmonic currents. Finally regarding the used winding specificities the possibility of second harmonic current supply is evaluated. The results are presented in a comparative way in order to determine the impact of rotor bar number on torque quality for the different supply modes.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/138002018-01-01T00:00:00ZMEKAHLIA, AbdelhakHAMITI, TaharBENLAMINE, RaoufSEMAIL, EricSCUILLER, FranckThe paper investigates the effect of the bar number on the performances of a five-phase squirrel-cage induction machine with fractional-slot tooth concentrated winding. With a same stator, five different rotor bar numbers are chosen and the rotor magnetic circuits are designed using an analytical approach. Then, a finite-element analysis is done under two different supply conditions: fundamental currents and third harmonic currents. Finally regarding the used winding specificities the possibility of second harmonic current supply is evaluated. The results are presented in a comparative way in order to determine the impact of rotor bar number on torque quality for the different supply modes.A bi-harmonic five-phase SPM machine with low ripple torque for marine propulsion
http://hdl.handle.net/10985/13422
A bi-harmonic five-phase SPM machine with low ripple torque for marine propulsion
ZAHR, Hussein; SEMAIL, Eric; SCUILLER, Franck
This paper addresses the design of a bi-harmonic five-phase Surface-mounted Permanent Magnet (SPM) machine for marine propulsion. The bi-harmonic characteristic results from the particular 20 slots-8 poles configuration that makes possible high value of third harmonic current injection. Thus the machine performance can be improved in terms of average torque, speed range, losses control and torque quality, this last feature being the scope of the paper. As low ripple torques are wanted at low speed, the magnet layer is defined to reduce the cogging torque and to make third harmonic current injection increasing average torque and reducing pulsating torque in the same time. According to a selection procedure based on the numerical simulations of a high number of machines, it appears that designing the rotor with two identical radially magnetized magnet that cover two-third the pole arc allows to reach this goal. Referring to an equivalent three-phase machine, the torque ripple level of the bi-harmonic five-phase machine is more than three times lower, thus being obtained with a simple control strategy that aims at achieving constant currents in the rotating frames. The time simulations of the drive confirm the significant reduction of the speed oscillation, especially at low speed.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/134222017-01-01T00:00:00ZZAHR, HusseinSEMAIL, EricSCUILLER, FranckThis paper addresses the design of a bi-harmonic five-phase Surface-mounted Permanent Magnet (SPM) machine for marine propulsion. The bi-harmonic characteristic results from the particular 20 slots-8 poles configuration that makes possible high value of third harmonic current injection. Thus the machine performance can be improved in terms of average torque, speed range, losses control and torque quality, this last feature being the scope of the paper. As low ripple torques are wanted at low speed, the magnet layer is defined to reduce the cogging torque and to make third harmonic current injection increasing average torque and reducing pulsating torque in the same time. According to a selection procedure based on the numerical simulations of a high number of machines, it appears that designing the rotor with two identical radially magnetized magnet that cover two-third the pole arc allows to reach this goal. Referring to an equivalent three-phase machine, the torque ripple level of the bi-harmonic five-phase machine is more than three times lower, thus being obtained with a simple control strategy that aims at achieving constant currents in the rotating frames. The time simulations of the drive confirm the significant reduction of the speed oscillation, especially at low speed.