LITERATURE SURVEY OF PERMANENT MAGNET AC MOTORS AND
P. PILIAY, MEMBER, IEEE, AND P. EREERE
Department of Electrical Engineering,
University of Newcastle upon Tyne,
NE1 7RU, England.
ABSTRACT starting torque) and inverter fed as shown in
figure 1. Inverter fed machines may have a cage,
Permanent magnet (PM) motors and drives are although frequently they do not. If a cage is used,
being used increasingly in a wide range of then it is possible to operate the machine on open
applications, which include machine ' tools, loop, like the line start machine. If the machine
robotics, aerospace generators and actuators and is cageless, then normally some form of rotor
electric vehicles. This has been made possible with position detection is necessary; this may be done
the advent of high performance permanent magnets with hall sensors, absolute optical encoders,
with high coercivity and residual magnetism, which resolvers or some form of sensorless position
make it possible for the PM to have superior power detection. Note that in the latter, the position
density, torque to inertia ratio and efficiency, loop is closed, even though there is no position
when compared to an induction or conventional DC sensor.
It is possible to classify the cageless motor
This paper surveys the literature of the PM drives into essentially two types. The first uses
motor and drives and includes line-start as well as continuous rotor position feedback to force
inverter fed applications and designs. The currents into the rotor. The ideal motor back emf
inverter-fed literature is divided into two, those is sinusoidal, so that when sinusoidal currents are
that deal with drives that use discrete feedback input, a constant torque is produced with very l o w
every 6' (electrical) for a three phase machine, ripple. There is also the possibility of feeding
and those that deal with drives that use continuous this machine with PWM voltages, without any direct
feedback. In the former, the ideal machine back emf attempt to control the waveform of the current. In
is trapezoidal and in the latter it is sinusoidal. this paper, this is called a permanent magnet
The paper should prove useful to both researchers synchronous motor (PMSM) drive, since the motor was
as well as practising engineers as a signpost to originally produced by replacing the field coil and
the current state of the art. slip rings of a wound rotor synchronous motor with
a permanent magnet. It should be noted that this
1.0 INTRODUCTION definition is by no means standard and that other
nomenclature used include brushless ac, brushless
Permanent magnet (PM) motor drives have come DC or permanent magnet ac.
of age. The invention of high performance magnets,
like samarium cobalt and neodymium-boron-iron,have The second category is based on position
made it possible to achieve motor performances that feedback that is not continuous, but rather
can surpass the conventional DC or induction motors obtained at fixed points, for example every 6 0'
(IM). Particular areas where permanent magnet (electrical). This is called a brushless DC motor
drives can be superior include power density, (BDCM) drive, where typically the current is held
torque to inertia ratio, and efficiency. Hence, constant for at least 10 2' and hence is
depending on the application, there are many approximately rectangular in shape for a current-
instances where permanent magnet motor drives are fed machine. Alternatively, the voltage may be fed
preferable. in blocks of 120°, with just a current limit to
ensure that the motor current is held within the
Permanent magnet machines may be classified motor's capabilities. Again, the above definition
into line start (which uses a cage to provide is not standard and some of the nomenclature
to line start)
r - 7 Rectangular
Figure 1. Classification of permanent magnet motors and drives.
89CH2792-0/89/0000-074$01 .OO 0 1989 IEEE
mentioned above with respect to the permanent provided it is not saturated. Hence maximum torque
magnet synchronous motor drive, is also used to '
is obtained at a load angle greater than 9
describe the brushless DC motor drive. The
definitions are made with respect to the drive and [A21 reviews the development of line start
not the machines. The generic term used to describe PMSMs and considers the effects of variations of
both drives is permanent magnet ac motor drives. parameters on its performance, whereas [A31 looks
at the characteristics of various Nd-Fe-B magnets
Position sensorless drives typically are and views the possibilities for use in permanent
based on brushless DC motor drives, since position magnet line start motors.
information is required only every 60 electrical
degrees, instead of continously as in the PMSM An analysis of a PMSM (with a cage rotor)
drive. This makes sensorless implementation easier. operating off a fixed 60 Hz supply was done in [A4-
A7). A detailed steady state analysis was done
A fair amount of research work has been done [Ah], while the starting performance has been
on the machine design and modelling, as well as the studied [A5-A7] using the d,q axis equations of a
drive design and analysis. The main aim of this PMSM with damper windings, and also the design of
paper is to review the work done in the area of PM the motor in [A8]. Saturation on the q axis was
motors and drives. The review categorises the considered in [A5], the rotor cage contributing to
literature into a number of different areas like the iron saturation, due to the rotor induced
machine design, analysis, drive simulation etc. It currents.
should prove useful both to researchers as well as
practising engineers as a signpost to the current Parameter sensitivity of the self starting
state of the art. PMSM was considered in [A91 while the measurement
of motor parameters was examined in [AlO).
In order to keep the search comprehensive,
yet manageable, the following sources have been PMSM performance has been considered both
primarily consulted. after (All] and before [A121 synchronization. In
[All], the effects of iron losses are included in
1) IEEE Transactions on Industry Applications, the model. The effects of the magnet and cage
2) IEEE conference records of the Industry torques on the ability of the machine to run up on
Applications Society Annual Meetings, load are examined in detail and the subsynchronous
3 ) IEEE Transactions on Energy Conversion and torque is divided into its constituents. The line
the Power Apparatus and Systems, starting performance and steady state operation for
4 IEEE Transactions on Industrial Electronics,
) a single phase PMSM is dealt with by [A13].
5) IEEE Transactions on Magnetics, Conditions for balanced operation are also derived.
6) Proceedings of the IEE,
7) Proceedings of the Motorcon conferences, In (A14-A16], a similar study was done as in
8) IEE conference publications. [All,A12] but with a different emphasis. Torque
pulsations during starting were studied in [A141
Although not every paper in the above publications while design aspects were dealt with in [A151 and
are cited, it is believed that those that are, give criteria for synchronization in [A16]. In [A171 the
a fair indication of the progress made thus far. swing equation, necessary to study synchronization,
was derived. The inclusion of saturation in the
model was done in [Ala]. The effects of different
2 . 0 LITERATURE SURVEY OF THE PXSX designs on the machine performance were discussed
[A19,A20] while a performance analysis, using
The majority of work that has been done on finite elements as a tool, was presented in [A21].
the PMSM has been concerned with its operation from
a fixed frequency supply. Most of the earlier work A series of three papers: [A22], [A23],
was concerned with the starting of these machines [A24], consider the performance and analysis of the
using a cage on the rotor to provide induction machines with damper windings, taking into account
motor torque to run the machine up to almost space harmonics, current density distributions
synchronous speed; the magnet exerts a braking etc., and [A251 computes the winding inductances.
torque during this starting period. The machine
then pulls into synchronism with a combination of 2 . 2 THE INVERTER DRIVEN PXSX SYSTEn
the synchronous motor torque provided by the magnet
and a reluctance torque provided by unequal 2 . 2 . 1 PXSX XODELLING, ANALYSIS AND PERFORMANCE
inductance values on the periphery of the rotor.
Therefore, the first part of this literature survey Inverter driven PMSM's may have a cage, in
deals with the so called "self starting" PMSM. which case their construction can be similar to
that of the last section. It is more common,
though, to avoid the cage. This has a few
2.1 LINE STARTING PXSXs advantages. Firstly, the cage, which is in close
proximity to the magnet, is a direct source of heat
The mathematical modelling and performance on the rotor. The performance of the magnets,
analysis of a PMSM obtained by fitting a permanent however, degrade considerably with a rise in
magnet inside the cage rotor of an induction temperature. Removal of the cage makes the major
machine has been done [All. The magnets in these source of heat production occur in the stator, from
machines are frequently buried in the rotor to where it is more easily removed. It also makes the
provide space for the rotor cage close to the rotor construction easier. Finally, there is more
surface of the rotor. [All points out that the freedom available with respect to the location of
presence of the magnet provides a reluctance torque the magnet on the rotor.
that is opposite in sign to that of a wound rotor
synchronous machine. This occurs because the In the absence of a cage, the PMSM (and
permeability of the magnet on the direct axis is indeed the BDCM) can have a few different
close to that of air while the iron on the configurations of the rotor, as shown in [Bl] in
quadrature axis has a much higher permeability the context of a historical development of the
motors. The magnets may be placed on the surface of
the rotor (surface mounted, figure 2 ) , inset into
the rotor (inset mounted, figure 3 ) , or buried
within the rotor core (buried configuration, figure
4). These give rise to different motor
characteristics, and indeed, affect the behaviour
of the overall drive as well. A schematic of a
complete PMSM drive system is given in figure 5.
This assumes a resolver for position/velocity
feedback and appropriate current controllers to
force sinusoidal currents into the machine. The
literature search on inverter fed machines is
divided into papers that are concerned primarily
with machine design on the one hand, and with the
entire drive analysis or design on the other:
Classification of inverter driven PMSMs was
carried out by [BZ] in terms of the motor design,
power circuit configuration, commutation control
signals, current regulation and principal motor
control methods. [B3] generally compares the
characteristics of BDCMs and PMSMs. For permanent
magnet machines using rare-earth cobalt magnets,
[B4) investigates the power density limitations of
The dynamic model of a PMSM with no damper ro
windings [B5,B6] has also been derived, and using
linear d-q axis equivalent circuit theory for
surface mounted permanent magnet motors, [B7]
predicts the transient behaviour of the machine.
Modelling of both the PMSM and the BDCM was
Figure 3 . PM motor with inset magnet.
performed by [B8]. In the case of the PMSM, the d-q
axis transformation was used, but neglecting
saturation, hysteresis and eddy current losses.
An analysis based on the motor's
A detailed field analysis has been done [B9], electromagnetic equations was done in [B14], and
modelling in [BlO,Bll], and use of both lumped and using the ideas developed in [B15], a steady state
distributed parameters, combining both field and analysis of the PMSM when fed from a voltage [B16]
circuit equations in [B12], while in [B13] as well as a current source inverter [B17], has
particular attention was paid to the magnet been done. A steady state model has been developed
properties of a PMSM. that represents the excitation of a PMSM as an
magnet magnet rotor' core
Figure 2. PM motor with surface mounted magnets. Figure 4. PM motor with buried magnets-
1 TI ,T2,T3,T4,T5,Th
equivalent current source [B18], with a model for The possibility of operating the inverter
efficiency calculations being developed in [B19]. driven machine above rated speed by field weakening
Inclusion of an extra cross-coupling term to was examined in [B18]. The effects of the voltage
represent saturation in the model for buried source inverter on the motor performance has been
permanent magnet ac machines has been proposed analysed [B31] as well as the use of a half wave
[B20], while [B21] varies the lumped circuit bridge for self excitation in the event of loss of
parameters to take the saturation into account. magnetism [B32]. Extended speed operation using
field weakening was examined in [B20,B33-B37] while
A systematic procedure to obtain the machine the operating limits of a PMSM determined [B38]
parameters was shown in [B22]. The use of these using a previously developed model [Ble]. A new
parameters to predict the steady state performance flux weakening algorithm has also been developed
was also shown. [B23] developed an analytical model [B39].
for a surface mounted PMSM, by predicting the
magnetic circuit parameters from which the Prediction using finite element analysis, and
equivalent electrical circuit is derived. In comparison with experiment, of the cogging and
[B24,B25] it was shown how "permeance coefficients" commutation torques for both surface and buried
can be used in conjunction with finite element PMSMs, and then considering the effect of a
field solutions to obtain the parameters of a variation of the machines parameters (such as
machine. Taking account of the rotor saliency, magnet width) was carried out in [B40]. An
[B26] develops simple tests to measure the analytical technique for the torque analysis was
parameters and calculate the effective commutating presented by [B41]. Using a lossless equivalent
inductance. circuit, [B42] investigated the effect of the d-q
reactances and open circuit voltage on the power
[B27] offers a complete.mode1,the simulation capability of the machine. Consideration was also
and analysis of an entire drive system, for a given as to how to extend the speed, torque and
vector controlled PMSM system. State space models power capability. A PMSM with a multistacked,
of the motor and speed controller are used, as well imbricated rotor was considered by [B43] using a
as real-time models of the inverter switches and discrete reluctance circuit model to predict the
vector controller. Using both phasor diagrams and performance. In order to prevent possible
an admittance method, [B28] predicts the machines demagnetisation, [B44] looks at the short circuit
performance. More specifically. [B29) analyses a and transient torque capabilities of a NdFeB PMSM.
PMSM powered by a 10 phase controlled inverter,
in terms of the torque as a function of the phase A detailed study of the inverter behavior on
between the stator voltages and the rotor angle. the drive performance was made in [B45].
The parameter sensitivity of the PMSM was examined Complementary switching of the power devices was
in [B30] (in terms of the effects of temperature included and "loss of modulation" of the inverter
variations). examined at depth. Damper windings were not used,
the machine starting up on synchronous motor torque Electromagnetic considerations were used in (8631
only. A more detailed inverter description was to optimise the stator laminations for circular or
given in [B46]. trapezoidal stator slots. Design techniques to
reduce pulsating torques, obtaining low moment of
In [B47] a half speed design and in [B48] a inertia for fast response and optimizing magnet
microprocessor based speed controller was volume were all discussed in [B64]. A new half
designed. Digital modelling, using the 2-transform speed design has also been developed [B47].
was developed in [B49] to consider the case where
the current controller was implemented using analog Dual disc PMSMs are studied in [B65] and in
circuitry and a digital speed controller, and then [B66]. The former uses analytical field
also the case where both are digitally implemented, calculations to take into account the finite stator
assuming different sampling rates. iron permeability, as well as magnet leakage, while
the latter deals with the effects of stator teeth
composed of an iron/resin powder designed to
2.2.2 PMSM APPLICATIONS operate at 600Hz, amongst other design
A comparison of the application
characteristics of the BDCM and the PMSM was given By considering the area immediately around
by [B2], on the basis of power density, torque per the permanent magnets, [B67], [B68] and [B69]
unit current, speed range, feedback devices, propose analytical solutions to the effect of; the
inverter rating, cogging torque, ripple torque and PM on the airgap field, stator slotting and axial
parameter sensitivity. Consideration is also given fringing flux with stator slotting, respectively.
to the braking capability, losses and thermal
matters. [B70] describes a complete control system for
a 70 hp interior PMSM machine. It considers the
It was shown [B50] that the axial field PMSM operation in the constant torque mode, using vector
can offer improved performance over the radial control and in the constant power mode utilising
field PMSM. The possibility of replacing the square wave currents. [B71] uses a pseudo
standard induction motor used in industry with the differential speed controller and then simulates
PMSM, because of its higher efficiency and power the complete system to study various control
factor, was investigated in [B51], considering the strategies.
technical and economic aspects of an efficient
induction machine compared to a suitably designed
PM machine, seeking to obtain a satisfactory 3.0 LITERATURE SURVEY OF THE BRUSHLESS DC MOTOR
marginal pay back period based on the energy
savings of the permanent magnet motor. In Whereas the literature on the PMSM is split
considering the PMSM for electric vehicles, [B52] between its operation from fixed 50 or 60 Hz and
identifies several constraints in the use of a variable frequency supplies, all the literature on
vector controlled machine. The feasibility of the BDCM is concerned with its operation from
developing PMSMs of up to 125 HP has also been variable frequency supplies. The reason for this is
analysed, and new applications of the PMSM for that the PMSM requires only a sinusoidal supply to
run, which is readily available from the ac mains.
electric vehicles [B33] and the positioning of
The BDCM on the other hand, requires rectangular
space instrumentation has been researched [B53].
shaped stator currents to operate, which is only
obtainable from an inverter. The overall structure
of a BDCM drive is similar to that of the PMSM
2.2.3 DESIGN OF MACHINE AND/OR DRIVE SYSTEM
drive of figure 5. A crucial difference is that the
current commanded is rectangular, so that Hall
A brief history and comparison between
sensors located every 60 degrees can be used. Since
different types of magnets is given in [B54],
only two phases conduct at any one time, the
together with design possibilities for Ne-B-Fe
decoding necessary is easier and less expensive to
magnets, while [B55] considers the more general
implement than that required for the PMSM drive.
design constraints to give some design guidelines. The BDCM is defined in [Cl] in terms of the motor
A comparison of the design differences between the
description and its component parts.
PMSM and IM with respect to servo drives was made
in [B56]. The performance and design were Papers comparing and contrasting the
considered in [B57] as well as the impact of performance of a BDCM drive with other drives are
different motor designs on the drive system. A PMSM also being published. A comparison between the IM,
design both with and without a rotor cage for drive SM and BDCM drives has been done [C2]. Basic motor
applications has been presented [B58], and the configurations and feedback devices used in each
design and construction of a PMSM as a direct drive drive system were discussed. A comparison between a
servo motor, capable of supplying 400 Nm torque at BDCM and a DC excited synchronous reluctance motor,
270 rpm, was carried out by [B59]. Calculation of was given by [C3], and a comparison between a brush
the optimum size of the magnets for a PMSM was DC motor with a BDCM [C4]. Some of the qualities
performed by [B60], using the magnetic energy in required in high performance servos have been
the field and the finite element method. The listed [C5]. Some of the components used in BDCM
general design requirements are developed by [B61] and IH servo drive systems were discussed in (C61.
in terms of the operating requirements of the Some comparisons between the two were made as well
motor. and some differences between a BDCM and PMSM have
been presented [C7].
The impact of different motor designs, in
particular, different back emfs on the servo drive
performance, have been considered [B62]. The 3.1 BDCM MODELLING, ANALYSIS AND PERFORMANCE
appropriate current waveform needed to produce
constant output power was shown. In addition, Mathematical models for the BDCM were
design aspects, like the optimum motor inductance developed in [C8-C13]. In [CBI, an abc phase
value needed for best performance, were discussed. variable model was developed with the back emf
represented as a Fourier series. [BE] also develops published. In [C36] it was shown how a BDCM can be
an abc phase model, since the non-sinusoidal used to drive a solar powered pump. Applications of
variation of the mutual inductances renders a d-q the BDCM range from transit systems [C37] to a
axes transformation of little benefit. Some of the direct drive for a robot [C38].
simulation results were presented in [C9,ClO]. A
digital model was developed in [Cll]. A different The use of a linear BDCM, whenever linear
digital model for a BDCM was developed in [C13], reciprocating motion is required, has been
while [C14] includes the equations of the power suggested [C39]. This would remove the need for a
supply and motor to analyse the entire drive mechanical device to convert the rotating motion of
system. The operation of a BDCM from a voltage a conventional BDCM to linear motion, thus
source inverter has also been analysed [C15,C16]. improving accuracy and reliability.
In the latter, particular attention was paid to the
3.4 DESIGN OF MACHINE AND/OR DRIVE SYSTEM
The modelling, simulation and analysis of a
BDCM was completed by [C17] using a phase variable Conventional DC machines have operational
model to examine its performance as a speed servo difficulties at high speed operation. Techniques
drive system, powered by either P M or hysteresis
W for overcoming them by using BDCMs. are discussed
current controllers. The transient behaviour of the in [C40]. In [C41] some practical design problems
two controllers was also compared. For nonidealised of the BDCM were addressed. The properties of the
drives and machines, [ClEl uses a three phase state magnets used in the design of a BDCM have been
variable approach and discusses the effect of determined [C42,C43].
various approximations. When an equivalent circuit
or the d-q model are not easily applicable, [Cl91 The electronic circuit design for a BDCM
offers an alternative, which was used to consider drive system was discussed in [C44-C46]. The
transient response, parameter sensitivity and to electronics for sensorless starting is shown in
determine some design guidelines. [C44], for the generation of rectangular currents
using PWM in [C45] and interfacing problems
Performance equations were developed, and addressed in [C46]. Various power switching
differences between the BDCM and DC motor pointed circuits are considered in [C47] and compared on
out [C20]. A comparison between the performance of the basis of their efficiency and torque
a BDCM using two different magnet materials has production.
been made [C21]. The impact of motor and controller
designs on the BDCM servo drive performance has In order to achieve the maximum power density
been analysed [C22]. Techniques for high speed for a given frame size, [C48] approaches the
operation have also been presented. No damper problem by designing the motor to match the
windings were assumed to be on the rotor. In [C23] inverter characteristics. It is interesting that in
the effects of motor design parameters on the drive [C23] a seven phase machine is proposed, which is a
performance has been considered. Detailed studies break away from the traditional three phases.
of cogging torque have also been done [C24,C25]. Designs using unsymmetrical magnetization have been
Numerical solutions to the electromagnetic done [C49].
equations describing the magnetic fields of the
machine were obtained [C24] in order to calculate [C50] considers the design of a BDCM, in
the variation of cogging torque as a function of terms of the rotor (in particular imbricated or
the rotor position. Speed variations produced by segmented), and the type of magnets. The theory was
cogging torque have been analysed in [C25]. A supported by experimental results from a NdFeB
"claw-type'' stator for improved performance has motor. Some of the impacts of using a computer as a
been proposed in [C26]. design tool were discussed in [C12].
The effects of complex waveforms on the
output torque were studied in [C27,C28], while 4.0 CONCLUSIONS
commutation torque ripple was examined in [C29].
[C30] and [C31] look at the torque pulsations in a Although many areas have been covered by the
BDCM due to the non-idealised flux density and papers, much is yet to be done in the areas of
current waveforms, whereas [C32] modulates the machine design, control algorithms and drive
inverter's pulse width and phase, to increase design. As the technology for manufacturing the
torque at high speeds, which was then motors becomes more established and higher
experimentally demonstrated. performance magnets become available, it can be
expected that due to economies of scale, the cost
[C33] deals with a miniature, flat rotor of the machines and their drives will reduce,
BDCM. Due to the low inertia and the unevenly encouraging many more applications for the machines
distributed flux, torque ripple is apparent. The and drive systems.
paper studies the reduction of torque ripple using
an overlapping turn-on,and a PWM method.
Control of a BDCM by a microprocessor, with a REFERENCES
discussion of hardware and software options, was
dealt with by [C34]. Extending this was [C35], The references are divided into 3 sections,
where the digital signal processor utilises real each dealing with a particular type of permanent
time parameter identification, with speed and magnet motor or drive. These are:
A) line starting PMSMs
B) inverter fed PMSMs
3 . 3 BDCM APPLICATIONS C) BDCMs
After the design of the BDCM and associated
control electronic circuitry, papers on the
application of these drives to various systems were
A . LINE STARTING PMSUS [Ala] A. Consoli and A. Abela, "Transient
performance of permanent magnet AC motor drives,"
[All D.P.M. Cahill and B. Adkins, "The permanent IAS Annual Meeting, 1984, pp. 458-463.
magnet synchronous motor," Proc. IEE, vol. 109, pt.
A. no. 48, Dec. 1962, pp. 483-491. [A191 K.J. Binns, W.R. Barnard and M.A. Jabbar,
"Hybrid permanent-magnetsynchronous motors", Proc.
[A21 K.J. Binns and W.R. Barnard, M.A. Jabbar, IEE, vol. 125, no. 3., March 1978, pp. 203-208.
"Hybrid permanent-magnetsynchronous motors", Proc.
IEE, vol. 125. no. 3, March 1978, pp. 203 - 208. [AZO] K.J. Binns and M.A. Jabbar, "High-field self-
starting permanent-magnet synchronous motor," Proc.
[A31 T.W. Neumann and R. E. Tompkins, "Line start IEE, vol. 128, pt.B, no. 3, May 1981, pp. 157-160.
motor designed with Ne-Fe-Bpermanent magnets" 8th
Intl. Workshop on Rare Earth Magnets and Their [A211 K.J. Binns and T.M. Wong, "Analysis and
Applications, Dayton, Ohio, 1985, pp. 77 - 89. performance of a high-field permanent-magnet
synchronous machine," Proc. IEE, vol. 131, pt. B,
[A41 M.A. Rahman, "High efficiency permanent magnet no. 6 , November 1984, pp. 252-257.
synchronous motors," IAS Annual Meeting, 1979, pp.
561-564. [A221 T.M. Hijazi and N.A. Demerdash, "The impact
of the addition of a rotor-mounted damper bar cage
[A51 M.A. Rahman, T.A. Little and P.K. Dash, on the performance of a samarium-cobaltpermanent
"Computer simulation of the dynamic performance of magnet brushless DC motor system", IEEE Trans. on
permanent magnet synchronous motors," IAS Annual Energy Conv., vol. 3, no. 4, Dec 1988, pp, 890-898.
Meeting, 1981, pp. 511-514.
[A231 T.M. Hijazi and N.A. Demerdash, "Computer-
[A61 M.A. Rahman and T.A. Little, "Dynamic aided modeling and experimental verification of the
performance analysis of permanent magnet performance of power conditioner operated permanent
synchronous motors," IEEE Trans., vol. PAS-103,no. magnet brushless DC motors including rotor damping
6, June 1984, pp. 1277-1282. effects", IEEE Trans. on Energy Conversion, vol. 3,
no. 3, Sept. 1988, pp. 714 - 721.
[A71 M.A. Rahman, A.M. Oshiba and M.A. Choudhury,
"Run-up response of polyphase permanent magnet [A241 T.M. Hijazi and N.A. Demerdash, "Impact of
synchronous motors," Electric Machines and Power the addition of a rotor-mounted damper bar cage on
Systems, vol. 9 , 1984, pp. 347-356. the performance of samarium-cobaltpermanent magnet
brushless DC motor systems", IEEE Trans. on Energy
[A81 M.A. Rahman, "Design analysis of large Conv., vol. 3, no. 4, Dec. 1988, pp. 890 - 898.
permanent magnet synchronous motor", 8th Intl.
Workshop on Rare Earth Magnets and their [A251 N.A. Demerdash, T.M. Hijazi and A.A. Arkadan,
Applications, Dayton, Ohio, 1985, pp. 67 - 75. "Computation of winding inductance of permanent
magnet brushless DC motors with damper windings by
[A91 M.A. Rahman and A.M. Osheiba, "Effect of energy perturbation", IEEE Trans. on Energy Conv.,
parameter variations on the performance of vol 3, no. 3, Sept. 1988. pp. 705 - 713.
permanent magnet motors," IAS Annual Meeting,
1986, pp. 787-793.
B. INVERTER DRIVEN PMSMS
[A101 T.J.E. Miller, "Methods for testing permanent [Bl] M.A. Rahman, "Permanent magnet synchronous
magnet polyphase AC motors," IAS Annual Meeting, motors - a review of the state of design art,"
1981, pp. 494-499. Proc. Intl. Conference on Electrical Machines,
[All] V.B. Honsinger, "Performance of polyphase
Athens, 1980, pp. 312- 319.
permanent magnet machines," IEEE Trans., vol. PAS- [BZ] R.Colby, "Classification of inverter driven
99, no. 4, July/August 1980, pp. 1510-1518. permanent magnet synchronous motors," IAS Annual
Meeting, 1988, pp. 1 - 6.
[A121 V.B. Honsinger, "Permanent magnet machines:
Asynchronous operation," IEEE Trans., vol. PAS-99, [B3] P. Pillay and R. Krishnan, "Application
no. 4, July/August 1980, pp. 1503-1509. characteristics of permanent magnet synchronous and
brushless DC motors for servo drives," IAS Annual
[A131 A. Osheiba and M. Rahman, "Performance of Meeting, Atlanta, 1987, pp. 380-390.
line start single phase permanent magnet
synchronous motors," IAS Annual Meeting, pt. 1, [B4] E. Richter, "Power density considerations for
1987, pp. io4 - 108. permanent magnet machines", Electric Machines and
Electromechanics,vol. 4, July/Aug. 1979, pp. 21 -
[A141 T.J.E. Miller, "Transient performance of 32.
permanent magnet machines," IAS Annual Meeting,
1981, pp. 500-502. (851 P. Enjeti, J.F. Lindsay and M.H. Rashid,
"Parameter estimation and dynamic performance of
[A151 T.J.E. Miller, T.W. Neumann and E. Richter, permanent magnet synchronous motors," IAS Annual
"A permanent magnet excited high efficiency Meeting, 1985, pp. 627-633.
synchronous motor with line start capability," IAS.
Annu.l Meeting, 1982, pp. 455-461. [B6] P. Enjeti, J.F. Lindsay and M.H. Rashid,
"Stability and dynamic performance of variable
[A161 T.J.E. Miller, "Synchronization of line-start speed permanent magnet synchronous motors," IECON,
permanent-magnetAC motors," IEEE Trans., vol. PAS- 1985,~~. 749-754.
103, no. 7, July 1984, pp. 1822-1828.
[B7] T. Sebastian and G. Slemon, "Transient
[A171 M. Jufer, "Starting optimization of modelling and performance . of variable speed
synchronous permanent magnets motors," Proceedings permanent magnet motors," IAS Annual Meeting, pt.
of the Motorcon Conference, 1982, pp. 366-374. 1, 1987, pp. 3619 - 3621.
[BE] P. Pillay and R. Krishnan, "Modelling of [B24] A. Isizaki and Y. Yamamoto, "Asynchronous
permanent magnet motor drives," IEEE Trans. Ind. performance prediction of AC permanent magnet
Electronics,Vol 35, no. 4, Nov. 1988, pp. 537 - motor," IEEE Trans., vol. EC-1, no. 3. Sept. 1986,
541. pp. 101-108.
[B9] N. Boules, "Prediction of no load flux density [B25] A. Isizaki, T. Tabako and K. Saitoh,
distribution in permanent magnet machines," IAS "Prediction and improvement of synchronous
Annual Meeting, 1984, pp. 464-473. performance of AC permanent magnet motor," IAS
Annual Meeting, 1985, pp. 824-831.
[BlO] Y. Takeda, S. Morimoto and T. Hirasi,
"Generalised analysis of steady state [B26] S . F . Gorman, C. Chen and J.J. Cathey,
characteristics of DC commutatorless motors," Proc. "Determination of permanent magnet synchronous
IEE, vol. 130, pt. B, no. 6 , Nov. 1983, pp. 373- motor parameters for use in brushless DC motor
380. drive analysis", IEEE Trans. on Energy Conversion,
vol. 3, no. 3, Sept 1988, pp. 674 - 681.
[Bll] V. Ostovic, "Computation of saturated
permanent magnet AC motor performance by means of [B27] P. Pillay and R. Krishnan, "Modeling analysis
magnetic circuits," IAS Annual Meeting, 1986, pp. and simulation of a high performance, vector
794-799. controlled permanent magnet synchronous motor
drive," IAS Annual Meeting, Atlanta, 1987, pp. 253-
[B12) E.G. Strangers and T. Ray, "Combining field 261.
and circuit equations for the analysis of permanent
magnet AC motor drives", IAS Annual Meeting, Pt 1, [B28] V.B. Honsinger, "Performance of polyphase
1988, pp. 7 - 10. permanent magnet machines", IEEE Trans. on PAS, vol
PAS-99, no.4, July/August, 1980, pp. 1510 - 1518.
[B13] H.F. Mildrum, "Hard permanent magnet
development trends and their application to AC [B29] P. Krause, R. Nucera, R. Krefta and 0.
machines," IAS Annual Meeting, 1981, pp. 504-510. Waynczuk, "Analysis of a permanent magnet
synchronous machine supplied from a 180 degrees
[B14) B. Davat, H. Rezine and M. Lajoie-Mazenc, inverter with phase control," IEEE Trans. Energy
"Modelling of a brushless DC motor with solid parts Conversion, Vol EC2, no. 3, Sept. 1987, pp. 423 -
involving eddy currents," IAS Annual Meeting, 1982, 431.
[B30] R. Krishnan and P. Pillay, "Parameter
[B15] G.R. Slemon, "Analytical models for saturated sensitivity in vector controlled AC motor drives",
synchronous machines," IEEE Trans., vol. PAS-90, Proceedings of the IEEE IECON'87 conference, 1987,
no. 2, March/April 1971, pp. 409-417. pp. 212 - 218.
[B16] A.V. Gumaste and G.R. Slemon, "Steady state [B31] S. Funabiki and T. Hemei, "Estimation of
analysis of a permanent magnet synchronous motor torque pulsation due to the behavior of a converter
drive with voltage source inverter," IAS Annual
Meeting, 1980, pp. 618-625. and inverter in a brushless DC drive system,"
Proc.IEE, vol. 132, pt.B, no.4, July 1985, pp 215-
[B17] G.R. Slemon and A.V. Gumaste, "Steady state 222.
analysis of a permanent magnet synchronous motor
[B32] S . Nonaka and H. Takami, "Low speed drive of
drive with current source inverter," IAS Annual
Meeting, 1981, pp. 683-690. PWM VSI fed brushless self-excited synchronous
motor," IAS Annual Meeting, 1985, pp. 726-731.
[B18] T. Sebastian, G.R. Slemon and M.A. Rahman,
"Modelling of permanent magnet synchronous motors," [B33] G. Maggetto, B. Sneyers and J.L. van Eck,
IEEE Trans'.,vol MAG-22, no.9, Sept 1986, pp. 1069- "Permanent magnet motor used for traction
1086. purposes,",Proceedings of the Motorcon Conference,
1982, pp. 61-68.
[B19] R. Colby and D.W. Novotny, "Efficient
operation of a surface mounted permanent magnet [B34] M.Jufer and A. Perret, "Self controlled
synchronous motor," IAS Annual Meeting, 1986, pp. synchronous motor: performance improvement by lead
806-813. angle regulation," Proceedings of the Motorcon
Conference, 1983, pp. 532-541.
[B20] B. Sneyers, D.W. Novotny and T.A. Lipo,
"Field weakening in buried permanent magnet AC [B35] W.T. Fejes, "Computer simulation of torque
motor drives," IAS Annual Meeting, 1982, pp. 462- speed characteristics of a brushless servo system,"
468. Proceedings of the Motorcon Conference, 1985, pp.
[B21] M. Chen, E. Levi and M. Dov Pella, "Iron
saturation effects in PM AC motors", IEEE [B36] G.H. Holling and A. Persha1l;"The technique
Transactions on Magnetics, vol. Mag21, no. 3, May of phase advancing for brushless motors,"
1985, pp. 1262-1265. Proceedings of the Motorcon Conference, 1985, pp.
[B22] B.J. Chalmers, S.A. Hamed and G.D. Baines,
"Parameters and performance of a high field [B37] M. Steuer, "Extended speed-torque operation
permanent magnet synchronous motor for variable of permanent magnet synchronous motors,"
frequency operation," Proc. IEE, vol. 132, pt. B, Proceedings of the Motorcon Conference, 1985, pp.
no. 3, May 1985, pp. 117-124. 179- 183.
[B23] M. Rahman, "Analytical Models for Exterior [B38] T. Sebastian and G.R. Slemon, "Operating
Type Permanent Magnet Synchronous Motors." IEEE limits of inverter-drivenpermanent magnet motor
Transactions on Magnetics, vol. 23, no.5; Sept. drives," IAS Annual Meeting, 1986, pp. 800-803.
1987, pp. 3625 - 3627.
[B39] T.M. Jahns, "Flux weakening regime operation electrical machines", IEEE Trans. on Magnetics, vol
of an interior permanent magnet synchronous motor Mag-21, no. 5, Sept. 1985, 1712 - 1716.
drive," IAS Annual Meeting, 1986, pp. 814-823.
(B55] A. Levran and E. Levi, "Design of polyphase
[B40] J. De La Ree and J . Latorre, "Permanent motors with PM excitation", IEEE Trans. on
magnet machines torque considerations," IAS Annual Magnetics, vol Mag-20, no. 3, May 1984, pp. 507 -
Meeting, pt. 1, 1988, pp. 32 - 37. 515.
[B41] J . De la Ree and N. Boules, "Torque [B56] D. Pauly, G. Pfaff and A. Weschta, "Brushless
production in permanent magnet synchronous motors," servo drives with permanent magnet motors or
IAS Annual Meeting, pt. 1, 1987, pp. 15 - 20. squirrel cage induction motors - a comparison," IAS
Annual Meeting, 1984, pp. 503-509.
[B42] R. Schiferl and T.A. Lipo, "Power capability
of salient pole permanent magnet synchronous motors [B57] T.M. Jahns, G.B. Kliman and T.W. Neumann,
in variable speed drive applications", IAS Annual "Interior permanent magnet synchronous motors for
Meeting, pt. 1, 1988, pp. 23 - 31. adjustable speed drives," IAS Annual Meeting, 1985,
[B43] T. Low and W. Lee, "Characteristics and
performance analysis of a permanent-magnet motor [B58] P. Viarouge, M. I Lajoie-Mazenc and C.
with a multistacked imbricated rotor," IEEE Trans. Andrieux, "Design and construction of a brushless
Energy Conversion, Vol EC2, no. 3, 450 - 457 Sept. permanent magnet servomotor for direct drive
1987. applications," IAS Annual Meeting, 1986, pp. 781-
[B44] T. Sebastian and G.R. Slemon, "Transient
torque and short circuit capabilities of variable [B59] P. Viarouge, M. Lajoie-Mazene and C.
speed permanent magnet motors," IEEE Trans. of Andrieux, "Design and construction of a brushless
Magnetics, vol. 23, no. 5, pp. 3619 - 3621, Sept. permanent magnet servomotor for direct drive
1987. applications", IEEE Trans on Industry Applications,
Vol 1A-23, no. 3, May/June 1987, pp. 526 - 431.
[B45] M. Lajoie-Mazenc, C. Villaneuva and J.
Hector, "Study and implementation of hysteresis [B60] D. Pavlick, V. Garg, J. Repp and J. Weiss,
controlled inverter on a permanent magnet "Finite element technique for calculating magnet
synchronous machine," IEEE Trans., vol. 1A-21, no. sizes and inductances of permanent magnet
2, March/April 1985, pp. 408-413. machines," IEEE Trans. on Energy Conversion, vol.
3, no. 1, March 1988, pp. 116 - 122.
[B46] M. Lajoie-Mazenc, H. Foch and C. Villaneuva,
"Feeding permanent magnet machines by a (8611 H. Grostollen, G. Pfaff, A. Weschta, K.P.
transistorized inverter," Proceedings of the Kovacs, "Design and dynamic behaviour of a
Motorcon Conference, 1983, pp. 558-569. permanent magnet synchronous servo-motor with rare-
earth-cobalt magnets", Proc. of Intl. Conf. on
[B47] S . Nonaka and K. Fujii, "A new brushless Electrical Machines, Greece, Sept. 1980, pp. 320 -
half-speed synchronous motor with Q-axis squirrel- 329.
cage damper winding driven by voltage source
inverter," IAS Annual Meeting, 1986, pp. 896-901. [B62] A. Weschta, "Design considerations and
performance of brushless permanent magnet servo
[B48] M.F. Rahman, T.S. Low and L.B. Wee, motors," IAS Annual Meeting, 1982, pp. 469-475.
"Development of a digitally controlled permanent
magnet brushless DC drive system," Conference on [B63] D.E. Hesmondhalgh and D. Tipping, "Torque
Applied Motion Control, 1986, pp. 283-288. availability from synchronous motors using high
coercivity magnets", Proc. IEE, vol 132, Pt B, no.
[B49] P. Pillay and R. Krishnan, "Development of 5, Sept. 1985, pp. 279 - 288.
digital models for a vector controlled permanent
magnet synchronous motor drive", IAS Annual [B64] G. Pfaff, A. Weschta and A. Wick, "Design and
Meeting, 1988, pp. 476 - 482. experimental results of a brushless ac servo
drive," IAS Annual Meeting, 1982, pp. 692-697.
[B50] R. Krishnan and A.J. Beutler, "Performance
and design of an axial field PM synchronous motor [B65] H. Weh and N. Boules, "Field analysis for a
servo drive," IAS Annual Meeting, 1985, pp. 635- high power, high speed permanent magnet synchronous
640. machine of the disc construction type", Electric
Machines and Electromechanics, vol. 5. no. 1, Jan.
[B51] E. Richter, T.J.E. Miller and T.W. Neumann, 1980, pp. 25 - 37.
"The ferrite permanent magnet AC motor - A
technical and economic assessment," IAS Annual [B66] N. Boules and H. Weh, "Machine constants and
Meeting, 1984, pp. 1353-1358. design considerations of a high-power,high-speed
permanent magnet disc type synchronous machine",
[B52] K.J. Binns, B. Sneyers, G. Maggetto, Ph. Electric Machines and Electromechanics, vol. 5, no.
Lataire, "Rotor position controlled permanent 2, March/April 1980, pp. 113 - 123.
magnet synchronous machines for electric vehicles,"
Proc. Intl. Conference on Electrical Machines, [B67] G. Qishan and G. Hongzhan, "Air gap field for
Athens, 1980, pp 346 - 357. PM electrical machines", Electric Machines and
Power Systems, vol. 10, no.s 5-6, 1985, pp. 459 -
[B53] G. Champenois, P. Mollard and J.P. Rognon, 470.
".Synchronous motor drive: a special application,"
IAS Annual Meeting, 1986, pp. 182-189. [sa81 G. Qishan and G. Hongzhan, "Effect of
slotting in PM electric machines", Electric
[B54] M.A. Rahman and G.R. Slemon, "Promising Machines and Power Systems, vol. 10, no. 4, 1985,
applications of neodymium boron iron magnets in pp. 273 - 284.
[B69] G. Qishan and G. Hongzhan, "The fringing [Cl21 R.H. Miller, T.W. Nehl, N.A. Demerdash, B.P.
effect in PM electric machines", Electric Machines Overton and C.J. Ford, "An electronically
and Power Systems, vol. 11, no. 2, 1986, pp. 159 - controlled permanent magnet synchronous machine
169. conditioner system for electric passenger vehicle
propulsion," IAS Annual Meeting, 1982, pp. 506-510.
[B70] B.K. Bose, "A high performance inverter-fed
drive system of an interior permanent magnet [C13] P.F. Muir and C.P. Neumann, "Pulsewidth
synchronous machine", IAS Annual Meeting, pt. 1, modulation control of brushless DC motors for
1987, pp. 269 - 276. robotic applications," IEEE Trans., vol. IE-32, no.
3, August 1985, pp. 222-229.
[B71] P. Pillay and R. Krishnan, "Control
characteristics and speed controller design for a [Cl41 D.M. Erdman and H.B. Harms, "Estimating
high performance permanent magnet synchronous motor speed-torque profiles of the brushless DC motor,"
drive," IEEE Power Electronics Specialist Proceedings of the Motorcon Conference, 1985, pp.
Conference, 1987, pp. 598 - 606. 1-8.
[Cl51 A.K. Wallace and R.F. Spee, "The effects of
C. BDGMs motor parameters on the performance of brushless DC
drives," 1987 IEEE PESC, pp. 591-597.
[Cl] A. Kusko, "Definition of the brushless DC
motor," IAS Annual Meeting, pt. 1, 1988, pp. 20 - [C16] F.M.Vasquez, "Brushless DC motor simulation",
22. M.S. thesis, 1984, VPICSU.
[C2] E.K. Persson, "Brushless DC motors - a review (Cl71 P. Pillay and R. Krishnan, "Modelling,
of the state of the art," Proceedings of the simulation and ananlysis of a permanent magnet
Motorcon Conference, 1981, pp. 1-16. brushless DC motor drive", IAS Annual Meeting, pt.
1, 1987, pp. 7 - 14.
[C3] H. Gaede, "A new brushless DC drive for
industrial power ranges and applications," IEE [C18] R. Spee and A. Wallace, "Performance
conf. on Electrical Variable Speed Drives, vol. 93, characteristics of brushless DC drives", IAS Annual
1972, pp. 132 - 136. Meeting, pt. 1, p p . 1 - 6.
[C4] D.B. Jones, "Performance characteristics of DC [C19] A. Wallace and R. Spee, "The effects of motor
motors, both brush and brushless in incremental parameters on the performance of brushless DC
motion systems," Proceedings of the Motorcon drives", IEEE Power Electronics Council, Power
Conference, 1982, pp.. 392-407. Electronics Specialist Conference, PESC'87, pp. 591
[C5] P. Zimmermann, "Electronically commutated DC
feed drives for machine tools," Proceedings of the [C20] J. Mazurkiewicz, "Analysis of new compact
Motorcon Conference, 1982, pp. 69-86. brushless vs pancake motors," Proceedings of the
Motorcon Conference, 1983, pp. 521-531.
[C6] M. Brown and D. Moore, "Brushless DC or
inverter motor drives; a comparison of attributes," [C21] N.A. Demerdash, R.H. Miller, T.W. Nehl, B.P.
Proceedings of the Motorcon Conference, 1982, pp. Overton and C.J. Ford, "Comparison between features
111-123. and performance characteristics of fifteen HP
samarium cobalt and ferrite based brushless DC
[C7] H. Le-Huy, R. Perret and R. Feuillet, motors operated by same power conditioner," IEEE
"Minimization of torque ripple in brushless DC Trans., vol. PAS-102,no. 1, January 1983, pp. 104-
motor drives," IAS Annual Meeting, 1985, pp. 790- 111.
[C22] T.M. Jahns, "Torque production in permanent
[C8] T.W. Nehl, F.A. Fouad, N.A. Demerdash and E.A. magnet synchronous motor drives with rectangular
Maslowski, "Dynamic simulation of radially oriented current excitation," IEEE Trans., vol. IA-20,no.
permanent magnet electronically operated 4, July/August 1984, pp. 803-813.
synchronous machines with parameters obtained from
finite element field solutions," IEEE Trans., vol. [C23] H.R. Bolton, Y.D. Liu and N.M. Mallison,
IA-18. no. 2, March/April, 1982, pp. 172-181. "Investigation into a class of brushless DC motor
with quasisquare voltages and currents," Proc. IEE,
[C9] T.W. Nehl, F.A. Fouad and N.A. Demerdash, vol. 133, pt. B, no. 2, March 1986, pp. 103-111.
"Digital simulation of power conditioner - machine
interaction for electronically commutated DC [C24] J.A. Wagner, "Numerical analysis of cogging
permanent magnet machines," IEEE Trans.on torque in a brushless DC motor," IAS Annual
Magnetics, vol. MAG-17, no. 6 , Nov. 1981, pp. 3284 Meeting, 1975, pp. 669-674.
- 3286. [C25] G. Bretani, "The effects of the torque ripple
and cogging torque on the instantaneous speed
[ClO] N.A. Demerdash and T.W. Nehl, "Dynamic variation of a brushless DC motor," Proceedings of
modelling of brushless DC motors in electric the Motorcon Conference, 1985, pp. 20-30.
propulsion and electromechanical actuation by
digital techniques," IAS Annual Meeting, 1980, pp. [C26] G.W. Mclean, "Brushless DC drives using claw-
570-578. type stator and disc rotor," Proc. IEE, vol. 126,
no. 7, July 1979, pp. 683-689.
[Cll] N.A. Demerdash and T.W. Nehl, "Dynamic
modelling of brushless DC motors for aerospace [C27] V.K. Garg, N.A. Demerdash and J. Whited,
actuation," IEEE Trans., vol. AES-16, no. 6, "Effect of SCR complex waveforms on torque ratings
November 1980, pp. 811-821. of permanent magnet DC servo motors used for
digital control in machine tool industries," I A S
Annual Meeting, 1977, pp. 466-470. 1975
[C28] F. Perion, A. Razek, R. Perret and H. Le-Huy, [C44] K. Iizuka and H. Uzuhashi, "Microcomputer
"Torque characteristics of brushless DC motors with control for sensorless brushless motor," IAS Annual
imposed current waveform," IAS Annual Meeting, Meeting, 1984, pp. 618-624.
1986, pp. 176-181.
[C45] B.V. Murthy, "Fast response brushless DC
[C29] A. Fratta and A. Vagati, "DC brushless drive with regenerative braking," IAS Annual
servomotor: optimizing the commutation Meeting, pp. 445-450.
performances," IAS Annual Meeting, 1986, pp. 169-
175. [C46] E.H. Hopper, "Interfacing servomotors drives
and controls- today and tomorrow," Proceedings of
[C30) P. Pillay and R. Krishnan, "An Investigation the Motorcon Conference, 1983, pp. 512-520.
into the Torque Behaviour of a Brushless DC Motor
Drive", IAS Annual Meeting, pt. 1, 1988, pp. 201 - [G47] P.P. Acarnley, A.G. Jack and P.T. Jowett,
208, "Power circuits for small permanent-magnet
brushless DC drives", 3rd Intl. Conf. on Power
[C31] C.K. Patni and B.W. Williams, "The effect of Electronics and Variable Speed Drives, IEE Conf.
modulation techniques and electromagnetic design on publication 291, 1988, pp. 237 - 240.
torque ripple in brushless PM motors", 2nd Intl.
Conf. on Power Electronics and Variable Speed [G48] B.T. Ooi, P. Bissoneau and L. Brugel,
Drives, IEE Conf. publication 264, 1986, pp. 76 - "Optimal winding design of a permanent magnet motor
79. for self-controlled inverter operation", Electric
Machines and Electromechanics, vol. 6 , no. 5,
[C32] R. Becerra and M. Ehsani, "High speed torque Sept./Oct. 1981, pp. 381 - 389.
control of brushless permanent magnet motors", IEEE
Trans. on Industrial Electronics, vol. 35, no. 3 , [C49] A. Kusko and S.M. Peeran, "Brushless DC
August, pp. 402 - 406, 1988. motors using unsymmetrical field magnetization,"
'IAS Annual Meeting, 1986, pp. 774-780.
[C33] Y. Murai, Y. Kawase. K. Ohashi, K. Nagatabe
and K. Okuyama, "Torque ripple improvement for [C50] M. Jabbar, T. Low and M. Rahman, "Permanent
brushless miniature motors", IAS Annual Meeting, magnet motors for brushless operation", IAS Annual
pt. 1, 1987, pp. 21 - 26. Meeting, pt. 1, 1988, pp. 15 - 19.
[C34] W. Sakmann, "A brushless DC motor controlled
by a microprocessor with examples for a 3 phase ACKNOWLEDGEMENTS
motor," IEEE Trans. on Industrial Electronics, vol.
34, no. 3, Aug., 1988, pp. 339 - 344. P. Pillay would like to acknowledge the SERC for
funding his research at the University of Newcastle
[C35] N. Matsui and H. Ohashi, "DSP-based adaptive upon Tyne. He also acknowledges R. Krishnan, of the
control of a brushless motor," IAS Annual Meeting, Virginia Polytechnic Institute and State
pt. 1, 1988, pp. 375 - 380. University, for his help and suggestions during the
initial phases of this work.
[C36] J. Mazurkiewicz, "Submersible brushless motor
with integrated electronics," Proceedings of the
Motorcon Conference, 1983, pp. 542-548.
[C37] W.R. Pearson and P.G. Sen, "Brushless DC
motor propulsion using synchronous motors for
transit systems," IEEE Trans., vol. IE-31, no. 4.,
November 1984, pp. 346-351.
IC381 S. Williams, "Direct drive system for an
industrial robot using a brushless DC motor," Proc.
IEE, vol. 132, pt. B, no. 1, January 1985, pp. 53-
[C39] D.A. Topmiller, J . J . Cathey and C.H. Yang, "A
microprocessor D.A. based controller for
oscillatory mode drive of a tubular brushless DC
motor," IAS Annual Meeting, 1985, pp. 536-541.
[C40] M. Liska, "A new brushless variable speed DC
drive for 60,000 rev/min and torque output upto 50
Ncm," IEE conf. on Electrical Variable Speed
Drives, vol. 93, 1972, pp. 74 - 78.
[C41] R. Muller, "DC motors for special
applications," Proceedings of the Motorcon
Conference, 1982, pp. 299-309.
[C42] P. Campbell, "Modern permanent magnet
materials in rotating electrical machines,"
Proceedings of the Motorcon Conference, 1982, pp.
[C43] A.S. Rashidi, "High energy permanent magnets
in DC motors," Proceedings of the Motorcon
Conference, 1981, pp. 24-23.