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Journal ArticleDOI

Permanent-Magnet Synchronous Generator Supplying an Isolated Load

19 Jul 2010-IEEE Transactions on Magnetics (IEEE)-Vol. 46, Iss: 8, pp 3353-3356
TL;DR: In this paper, the steadystate and transient performance of a surface-inset permanent-magnet synchronous generator feeding an isolated load is studied using a coupled-circuit, time-stepping, two-dimensional finite-element analysis.
Abstract: The steady-state and transient performance of a surface-inset permanent-magnet synchronous generator (PMSG) feeding an isolated load is studied using a coupled-circuit, time-stepping, two-dimensional finite-element analysis. Nonlinearities in the field and electric circuit are taken into consideration and both passive ac load and bridge rectifier dc load operating conditions are analyzed. The main contribution of this paper is the quantitative analysis of voltage and current harmonics, as well as the study of short-circuit performance. The computed results have been verified by experiments on a 2.5 kVA generator.

Summary (1 min read)

Introduction

  • Permanent-magnet synchronous generators are increasingly used for distributed generation and many standalone applications.
  • For these applications the PMSG may supply a passive R-L load or a dc load via a diode bridge rectifier connected across the armature terminals [1].
  • The nonlinear electric and field systems pose considerable difficulties in analysis.
  • A time-stepping, coupled field-circuit finite element method [2], [3] is used for performance analysis of a surface-inset PMSG feeding an isolated load.
  • The analysis result helps in improving the generator design aspects.

II. ANALYSIS

  • The electric circuit of a star-connected PMSG that supplies a three-wire R-L load comprises six circuit variables, namely the resultant generated phase EMFs eA, eB, and eC and the phase currents iA, iB and iC.
  • The circuit element that represents the corresponding coil-side has three nodes (Ii, Ji, Ki).
  • Finally, the external circuit for isolated operation of the threephase AFPMSG is set up by including the load impedances.
  • In the case of a rectifier load, the actual circuit configuration depends upon the conduction states of the diodes, which are conveniently modelled by their Norton equivalent circuits.
  • The time-stepping, coupled field-circuit, 2-D FEA was performed in order to study the steady-state and transient performance of the experimental PMSG with surface-inset rotor [3].

III. GENERATOR PERFORMANCE

  • A. PMSG Supplying an Isolated Passive Load Fig. 3 shows the computed and experimental waveforms of the PMSG on no load and Fig. 4 shows the computed and experimental waveforms of phase voltage and phase current when the PMSG is supplying a load resistance of 9.1 Ω per phase.
  • Agreement between the computed and experimental waveforms is good in general, but the deviation in frequency becomes more pronounced due to the speed drop in the experimental machine set, a fact which was not accounted for in the FEA.
  • All the triplen harmonics are absent, while most of the harmonics decrease as the load current increases.

IV. CONCLUSIONS

  • The performance analysis of a permanentmagnet synchronous generator with inset rotor feeding an isolated load using a coupled-circuit, time-stepping, 2-D FEM is described.
  • The direct-coupled field-circuit method enables the instantaneous value of field and circuit variables to be solved simultaneously without using the D-Q axis model of the generator.
  • Both steady-state and transient operation of the PMSG can be analyzed.
  • PMSG supplying a rectifier load can also be handled.
  • A short-circuit study reveals regions of the rotor permanent magnet that might suffer from partial demagnetization.

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11. ELECTRIC MACHINES AND DRIVES: CMP-290
Permanent-Magnet Synchronous Generator
Supplying an Isolated Load
T. F. Chan
1
, Weimin Wang
1
, and L. L. Lai
2
1
Department of EE, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
2
Energy Systems Group, School of Engineering and Mathematical Sciences, City University London, UK
eetfchan@polyu.edu.hk
Abstract — The steady-state and transient performance of a
surface-inset permanent-magnet synchronous generator (PMSG)
feeding an isolated load is studied using a coupled-circuit, time-
stepping, two-dimensional finite-element analysis. Nonlinearities
in the field and electric circuit are taken into consideration and
both passive ac load and bridge rectifier dc load operating
conditions are analyzed. The main contribution of this paper is
the quantitative analysis of voltage and current harmonics, as
well as the study of short-circuit performance. The computed
results have been verified by experiments on a 2.5 kVA
generator.
I. INTRODUCTION
Permanent-magnet synchronous generators (PMSGs) are
increasingly used for distributed generation and many stand-
alone applications. For these applications the PMSG may
supply a passive R-L load or a dc load via a diode bridge
rectifier connected across the armature terminals [1]. The
nonlinear electric and field systems pose considerable
difficulties in analysis. In this paper, a time-stepping, coupled
field-circuit finite element method [2], [3] is used for
performance analysis of a surface-inset PMSG feeding an
isolated load. Besides the field characteristics, the coupled
field-circuit solution also yields other useful generator
information, taking into consideration the armature current
effect, magnetic saturation, and circuit nonlinearities. The
analysis result helps in improving the generator design
aspects. The computed results have been verified by
experiments on a 2.5 kVA generator.
II.
A
NALYSIS
The electric circuit of a star-connected PMSG that supplies a
three-wire R-L load comprises six circuit variables, namely
the resultant generated phase EMFs e
A
, e
B
, and e
C
and the
phase currents i
A
, i
B
and i
C
. The external circuit comprises the
armature resistance R, armature end-winding leakage
inductance L
e
, and the load impedance. In the case of a PMSG
supplying a bridge rectifier load (Fig. 1), the additional circuit
components include the six diodes D
1
to D
6
, the load
resistance R
L
, and the load inductance L
L
. In the present FEA
study the field-circuit coupling is accomplished via the phase
EMFs e
A
, e
B
, and e
C
, each of which being the sum of the e.m.f.s
of all the coil-sides that make up the phase winding. The field
region occupied by a coil-side has vector potential, current
and EMF degrees of freedom (DOFs). The circuit element that
represents the corresponding coil-side has three nodes (I
i
, J
i
,
K
i
). I
i
and J
i
are the negative and positive nodes that have the
Voltage degrees of freedom, and each of these nodes is
connected to that of the adjacent coil sides, depending upon
the winding configuration. The third node K
i
is a selected
node in the conductor field region and it has both current and
EMF degrees of freedom. Since all the current and back EMF
variables in the conductor field region have already been
unified, the vector potentials of all these nodes will be used to
evaluate the back EMF and current to be returned to node K
i
.
The field region and the corresponding circuit component are
thus coupled together. Each phase winding can now be
constructed by connecting the appropriate circuit elements.
Finally, the external circuit for isolated operation of the three-
phase AFPMSG is set up by including the load impedances.
In the case of a rectifier load, the actual circuit
configuration depends upon the conduction states of the diodes,
which are conveniently modelled by their Norton equivalent
circuits. Each diode is represented by a piecewise-linearized
current-voltage curve, defined by the forward voltage, forward
resistance and the reverse blocking resistance.
Maxwell’s equations, applied to PMSG domains, will give
rise to the diffusion equations:
()vA0,
×∇× =
in iron and air gap
(),
s
i
s
vA
×∇× =
in armature windings (1)
()(),
P
M
vA vB
PMr
×∇×=× in permanent magnets
where A,
ν
, i
s
, S, B
r
and
ν
PM
are magnetic vector potential,
reluctivity, armature phase current, total cross-sectional area
of one turn, remanent flux density of the PM and equivalent
reluctivity, respectively.
By applying periodic conditions, the solution region can
be confined to a half cross-section of the PMSG (Fig. 1). In
this work, a time-step corresponding to two mechanical
degrees of rotor movement was found to give satisfactory
results without unduly long computation time.
Fig. 1. Cross-section of prototype PMSG with inset rotor construction
feeding a rectifier load
This is the Pre-Published Version.

11. ELECTRIC MACHINES AND DRIVES: CMP-290
Fig. 2. Cross-section of PMSG with surface-inset rotor and the flux plot
obtained from FEA
The time-stepping, coupled field-circuit, 2-D FEA was
performed in order to study the steady-state and transient
performance of the experimental PMSG with surface-inset
rotor [3]. Constant speed operation is assumed and the PMSG
supplies an isolated load. Both passive load and rectifier load
cases are analyzed. Fig. 2 shows the cross-section of the
machine and the field plot obtained.
III. GENERATOR PERFORMANCE
A. PMSG Supplying an Isolated Passive Load
Fig. 3 shows the computed and experimental waveforms of
the PMSG on no load and Fig. 4 shows the computed and
experimental waveforms of phase voltage and phase current
when the PMSG is supplying a load resistance of 9.1 Ω per
phase. It is observed that the waveforms computed from FEA
match the experimental waveform very closely, thus verifying
the validity of the field computation method. It is found that
there is marked distortion in the phase voltage waveform
when the PMSG is on load. To study the effect of load current
on the harmonics, a harmonic analysis was carried out on the
waveforms computed from FEA. From Fig. 5, it is seen that
both the 3rd and 15th harmonics increase with load current,
while the 9th triplen harmonics remains constant. On the other
hand, the non-triplen harmonics mostly decrease with increase
in load current. It can be concluded that the increased
harmonic distortion in phase voltage is due to increase in the
triplen harmonics. Since a three-wire load is being supplied,
the current waveform in Fig. 4 is practically sinusoidal since
triplen harmonics are suppressed across the lines. On no load,
the total harmonic distortion (THD) in the phase voltage and
line voltage is 5.3% and 3.45%, respectively. At full load (13
A), the THD in the phase voltage is 9.4 %, whereas THD in
the line voltage (and load current) is only 2.5%.
B.
Transient Switching of Isolated Passive Load
The time-stepping coupled field-circuit method was next
used to study the transient performance of the PMSG. The
PMSG was operating on no-load at rated speed when a balanced
resistive load of 12.45 Ω per phase was switched across the
generator terminals. As shown in Fig. 6, a brief transient period
follows the application of load at time t = 1.018 s, and a notch is
produced in the voltage waveform. Agreement between the
computed and experimental waveforms is good in general, but
the deviation in frequency becomes more pronounced due to the
speed drop in the experimental machine set, a fact which was
not accounted for in the FEA.
-100
-50
0
50
100
1 1.005 1.01 1.015 1.02 1.025 1.03 1.035
Time (s)
Phase voltage (V)
Computed Experimental
Fig. 3. Computed and experimental waveforms of no-load phase voltage
-100
-50
0
50
100
1.005 1.01 1.015 1.02 1.025 1.03 1.035
Time (s)
V
ph
(V) , I
ph
(x 0.2 A)
Vph (Comp.) Iph (Comp.) Vph (Expt'l) Iph (Expt'l)
Fig. 4. Computed and experimental waveforms of phase voltage and phase
current when the PMSG is supplying a load resistance of 9.1 Ω per phase
0
2
4
6
8
0246810121
Load current (A)
V
n
/V
1
x 100 (%)
4
n = 3 n = 5 n = 7 n = 9 n = 11 n = 13 n = 15 n = 17 n = 19
Fig. 5. Computed harmonics in the phase voltage when the PMSG is
supplying a resistive load
-120
-80
-40
0
40
80
120
1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08
Time (s)
Voltage (V), Current (x 0.2 A)
Phase voltage (Comp.) Phase current (Comp.) Phase voltage (Expt'l.) Phase current (Expt'l.)
Fig.6. Waveforms of phase voltage and phase current when a load resistance
of 12.45 Ω per phase is switched across the generator terminals

11. ELECTRIC MACHINES AND DRIVES: CMP-290
C. Short-circuit Transients
The time-stepping coupled field-circuit method was also
used for studying the short-circuit performance of the PMSG
and the computed results are shown in Fig. 7. The PMSG is
assumed to be running on open circuit when a three-phase short
circuit occurs at the terminals. Since triplen harmonic currents
cannot flow, the triplen harmonic voltage components remain in
each phase during the short circuit (Fig. 7). The steady-state
short-circuit current, however, is quite sinusoidal as observed
from Fig. 8. The peak short-circuit current reaches 131 A, while
the steady-state short-circuit current is 107 A (peak), or 76 A
(rms), which is almost six times the rated current.
Fig. 9 shows the distribution of the normal flux density at
the mean air gap of the PMSG computed at the instant when
maximum short-circuit current (131 A) is flowing. Due to the
inset rotor construction, the flux density is large in the interpolar
regions (I) where the soft iron rotor pole pieces are located.
Over the surfaces of magnets (II), however, the flux density is
smaller due to the demagnetizing effect of the armature currents.
Fig. 10 shows the computed flux density distribution at
different radial positions of a rotor magnet at the same time
instant. It is observed that there are regions in the rotor magnet
with flux reversal, i.e., flux density less than zero. This implies
that partial demagnetisation in the magnet will result subsequent
to a terminal three-phase short circuit.
-100
-50
0
50
100
1.005 1.015 1.025 1.035 1.045 1.055 1.065 1.075
Time (s)
Phase voltage (V)
Va Vb Vc
Fig. 7. Three-phase short-circuit transients of PMSG: phase voltage
waveforms
-150
-100
-50
0
50
100
150
1.005 1.015 1.025 1.035 1.045 1.055 1.065 1.075
Time (s)
Phase current (A)
Ia Ib Ic
Fig. 8. Three-phase short-circuit transients of PMSG: phase current
waveforms.
-2
-1
0
1
2
0 120 240 360 480 600 720
Electrical angle (deg.)
Flux density (T)
I
Fig. 9. Computed air gap flux density distribution of PMSG when phase A
is carrying maximum instantaneous short-circuit current
(I: interpolar regions; II: surfaces of magnets)
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 30 60 90 120 150 180
Circumferential distance (Elect. Deg.)
Flux density (T)
Outer radius Mean radius Inner radius
Fig. 10. Computed flux density at different radial positions of a rotor magnet
when phase A is carrying maximum instantaneous short-circuit current
D. PMSG Supplying a Rectifier Load
Fig. 11 shows the computed and experimental phase
voltage waveforms of the PMSG-rectifier-load system when
R
L
= 9.2 Ω and L
L
= 0. Compared with the waveforms for
passive loads (Fig. 4), the harmonic distortion the phase
voltages and phase currents is more severe due to the
nonlinear load. During commutation overlap, the phase
voltage is approximately constant at 50 V while the phase
current increases (or decreases) approximately linearly, giving
rise to quasi-trapezoidal current pulses in the positive and
negative half cycles (Fig. 12). The good agreement between
computed and experimental waveforms confirms the validity
of the coupled field-circuit FEA as applied to a PMSG
supplying rectifier loads.
Fig. 13 shows the variation of voltage harmonics with
load current of the PMSG from a Fourier analysis of the
computed waveforms. It is found that variation of the triplen
harmonics is practically the same as that for the passive load
case. The variation of non-triplen harmonics, however, shows
a great difference. The predominant harmonic is the 5th, and it
increases rapidly with load current. As a result the THD in the
line voltage also increases with load.
Fig. 14 shows the corresponding variation of harmonics in
the phase current. The harmonic contents are large as a result
of the nonlinear rectifier load. All the triplen harmonics are
absent, while most of the harmonics decrease as the load
current increases. The THD in the phase current drops from
27% to 20.6% as the load current increases from 2.8 A to 11.7
A.
I
II II
II
I

11. ELECTRIC MACHINES AND DRIVES: CMP-290
Fig. 15 shows the computed and experimental waveforms
of the phase current when R
L
= 9.2 Ω and L
L
= 11.27 mH.
Compared with the waveforms in Fig. 12 (when there is no
filter inductance), the ripple content in the phase current (and
hence the dc load current) is reduced considerably. A filter
inductance L
L
in series with R
L
in the circuit shown in Fig. 1 is
thus useful in improving the quality of the output current.
-100
-50
0
50
100
1.005 1.01 1.015 1.02 1.025 1.03 1.035
Time (s)
Phase voltage (V)
Computed Experimental
-20
-10
0
10
20
1.005 1.01 1.015 1.02 1.025 1.03 1.035
Time (s)
Phase current (A)
Computed Experimental
Fig. 11. Waveforms of phase voltage when the PMSG is supplying
a rectifier load (R
L
= 9.2 Ω)
-20
-10
0
10
20
1.005 1.01 1.015 1.02 1.025 1.03 1.035
Time (s)
Phase current (A)
Computed Experimental
Fig. 15. Computed and experimental waveforms of phase current when the
PMSG is supplying a rectifier load (R
L
= 9.2 Ω, L
L
= 11.27 mH)
IV.
CONCLUSIONS
In this work, the performance analysis of a permanent-
magnet synchronous generator with inset rotor feeding an
isolated load using a coupled-circuit, time-stepping, 2-D FEM
is described. The direct-coupled field-circuit method enables
the instantaneous value of field and circuit variables to be
solved simultaneously without using the D-Q axis model of
the generator. Both steady-state and transient operation of the
PMSG can be analyzed. PMSG supplying a rectifier load can
also be handled. A short-circuit study reveals regions of the
rotor permanent magnet that might suffer from partial
demagnetization. Based on waveforms computed from FEA, a
quantitative analysis of the harmonics and THD of a PMSG is
also presented and interesting results have been obtained for
both passive load and rectifier load. The computed results are
validated through measurements on a 2.5 kVA prototype
generator.
Fig. 12. Waveforms of phase current when the PMSG is supplying
a rectifier load (R
L
= 9.2 Ω)
0
2
4
6
8
10
12
14
16
0246810
Load current (A)
V
n
/V
1
x 100 (%)
12
n = 3 n = 5 n = 7 n = 9 n = 11 n = 13 n = 15 n = 17 n = 19
V. ACKNOWLEDGMENT
The work described in this paper was fully supported by a
grant from the Research Grants Council of the Hong Kong
Special Administrative Region, China (Project No. PolyU
5121/06E).
Fig. 13. Computed harmonics in the phase voltage when the PMSG
is supplying a rectifier load
0
5
10
15
20
25
0246810
Load current (A)
I
n
/I
1
x 100 (%)
VI. REFERENCES
[1] O. Ojo and J. Cox, “Investigation into the performance characteristics of
an interior permanent magnet generator including saturation effects,” in
Conf. Rec. 1996 IAS Annual Meeting, vol. 1, pp. 533-540.
[2] S. Williamson and A. F. Volshenk, “Time-stepping finite-element analysis
for a synchronous generator feeding a rectifier load,” IEE Proc.
Elect.
Power Appl., 142(1): 50–56, 1995.
12
n = 5 n = 7 n = 11 n = 13 n = 17 n = 19
[3] T. F. Chan, L. L. Lai and L. T. Yan, “Analysis of a stand-alone
permanent-magnet synchronous generator using a time-stepping coupled
field-circuit method,” IEE Proc.
Elect. Power Appl., 152(6): 1459-1467,
2005.
Fig. 14. Computed harmonics in the phase current when the PMSG is
supplying a rectifier load
Citations
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TL;DR: This paper demonstrates a multiplatform hardware-in-the-loop (HIL) approach to observe the operation of a high-speed permanent-magnet synchronous generator coupled with a microturbine in an all-electric-ship power system.
Abstract: This paper demonstrates a multiplatform hardware-in-the-loop (HIL) approach to observe the operation of a high-speed permanent-magnet synchronous generator coupled with a microturbine in an all-electric-ship power system. The mathematical model of the gas turbine and the dynamic equations of the high-speed generator are implemented in real time on a field-programmable gate array (FPGA). This real-time simulation interfaces with hardware via a serial peripheral interface to a supervisory digital signal processor (DSP) of a three-phase voltage source inverter. The inverter output load is virtually emulated in the FPGA using received hardware measurements from the DSP. A user input interface is introduced using dSPACE on a personal computer to acquire data and adjust the speed reference of the generator system through a serial communication interface to the DSP. The real-time simulation and HIL experimental setup are validated in a scaled medium voltage dc ship power system.

88 citations


Cites background from "Permanent-Magnet Synchronous Genera..."

  • ...2, it is assumed that the PMSG is directly connected with a PFC converter to reflect a purely resistive load characteristic on the stator terminals of the PMSG [31]....

    [...]

  • ...Cross section of the PMSG with inset rotor construction feeding a PFC power electronics converter [31]....

    [...]

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TL;DR: The voltage control, load compensation, and fuel efficiency improvement in PMSG-based DG set using BESS and DSTATCOM controlled by hyperbolic tangent function-based LMS algorithm are the main contributions of this paper.
Abstract: This paper deals with the voltage control and load leveling of permanent magnet synchronous generator (PMSG)-based diesel generator (DG) set for standalone supply system. The proposed system is composed of a PMSG and a prototype of diesel engine (DE), along with the distribution static compensator (DSTATCOM) and battery energy storage system (BESS). The DSTATCOM along with BESS is used for loads leveling and voltage control. It also provides balancing of loads, elimination of harmonics, and compensation of reactive power. The battery on dc link of voltage source converter (VSC) of DSTATCOM is used to supply the active power when the load is more than PMSG rating, and it stores the energy during light load periods. The PMSG is always loaded with an optimum load of 80%-100% of its rating. An optimum loading of DG set helps in improving the fuel efficiency of the DE and also helps in load leveling. The reference source currents are estimated using a hyperbolic tangent function-based least mean square (LMS) algorithm. This control algorithm has reduced computation and provides fast convergence rate to eliminate the effect of noise as compared with other LMS algorithms based on adaptive filtering. The voltage control, load compensation, and fuel efficiency improvement in PMSG-based DG set using BESS and DSTATCOM controlled by hyperbolic tangent function-based LMS algorithm are the main contributions of this paper.

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TL;DR: An equivalent magnetic circuit model of a new double-radial PM generator is established using the traditional equivalent circuit method and data analysis, the calculation formulas of permeance and leakage permeance in magnetic circuits in detail are introduced, and the influence factors of the LP are analyzed.
Abstract: The structure and magnetic circuit of the modern permanent magnet (PM) generator are often very complicated, which makes the traditional finite element analysis of magnetic field highly difficult. This paper establishes an equivalent magnetic circuit model of a new double-radial PM generator using the traditional equivalent circuit method and data analysis, introduces the calculation formulas of permeance and leakage permeance (LP) in magnetic circuits in detail, analyzes the influence factors of the LP, and provides the solutions. These studies will have a certain guiding significance for the design and optimization of generator circuits. To obtain the best matching parameters, the main parameters of the generator are tested and analyzed, such as the thickness of PM steel in the magnetization direction, length of PM steel, number of pole pairs, and the thickness of spacer bush. Finally, a prototype is tested, and the results show that the output characteristics of the designed double-radial PM voltage-stabilizing generation device are very good.

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Cites background from "Permanent-Magnet Synchronous Genera..."

  • ...[9] analyzed the steady-state and transient performance of a surface-inset PM synchronous generator that feeding an isolated load used a coupled-circuit, time-stepping, and 2D finite-element analysis....

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TL;DR: In this paper , an experimental performance comparison of self-excited induction generator (SEIG) and permanent magnet synchronous generator (PMSG) for renewable energy-based standalone applications is presented.

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20 Nov 2014
TL;DR: In this paper, the SynRM as a special case of the wound-rotor synchronous generator is considered and a control strategy to operate a SynRM in an extended speed range while reducing cooper loses is proposed.
Abstract: This paper targets to the challenge of electrical energy production and energy efficiency by studying synchronous reluctance machines (SynRM), as an alternative to permanent magnet generator in electric power generation with focus in renewable energy applications. Considering the SynRM as a special case of the wound-rotor synchronous generator, this paper explores the operating limits of the machine and proposes a control strategy to operate a SynRM in an extended speed range while reducing cooper loses. Numerical simulation is used to demonstrate the feasibility of this solution and to validate the analysis.

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  • ...A popular solution is provided by permanent magnet synchronous machines (PMSM) when high power density, high reliability and low maintenance are required [2][3]....

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  • ...Even though SynRMs have been used mainly as motors, the afore mentioned characteristics are highly desirables for generators, for this reason, the use of this kind of machines in electrical generation is gaining attraction [2][9][11]....

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References
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Journal ArticleDOI
01 Jan 1995
TL;DR: In this article, a time-stepping analysis for a salient-pole generator feeding a rectifier load, using a finite-element field model to update inductances where appropriate to allow for changes in rotor orientation and magnetic saturation, is presented.
Abstract: The paper describes a time-stepping analysis for a salient-pole generator feeding a rectifier load, using a finite-element field model to update inductances where appropriate to allow for changes in rotor orientation and magnetic saturation. The method includes a technique that allows skew to be represented. It is shown that if skew is not properly accounted for, spurious slot ripples will appear in the waveforms.< >

34 citations


"Permanent-Magnet Synchronous Genera..." refers methods in this paper

  • ...In this paper, a time-stepping, coupled field-circuit finite element method [2], [3] is used for performance analysis of a surface-inset PMSG feeding an isolated load....

    [...]

Proceedings ArticleDOI
06 Oct 1996
TL;DR: In this article, the analysis and computer simulation of an interior permanent magnet generator feeding an impedance load, a rectifier load and a rectifiers-PWM inverter connected to the impedance load is presented.
Abstract: The availability of high-energy permanent magnet materials has brought about renewed interest in the use of permanent magnets to provide field excitation in electric generators for use in industrial and utility applications. This paper sets forth the analysis and computer simulation of such an interior permanent magnet generator feeding an impedance load, a rectifier load and a rectifier-PWM inverter connected to an impedance load. The analysis accounts for the changing saturation and armature reaction dependent axes inductances and magnet flux linkage. Experimental results from a 2 HP interior permanent magnet generator system corroborate the analysis and computer simulations.

20 citations


"Permanent-Magnet Synchronous Genera..." refers background in this paper

  • ...For these applications the PMSG may supply a passive R-L load or a dc load via a diode bridge rectifier connected across the armature terminals [1]....

    [...]

Journal ArticleDOI
21 Nov 2005
TL;DR: In this paper, the performance analysis of a stand-alone permanent-magnet synchronous generator with inset rotor using a coupled-circuit, time-stepping, two-dimensional finite-element method is described.
Abstract: The performance analysis of a stand-alone permanent-magnet synchronous generator with inset rotor using a coupled-circuit, time-stepping, two-dimensional finite-element method is described. The direct-coupled field-circuit method enables the instantaneous values of the field and circuit variables to be solved simultaneously, without having to evaluate the synchronous reactances and the load angle. Magnetic saturation is accounted for by considering the flux densities in the elements of the field solution region. Besides the load characteristics, the coupled field-circuit solution also yields other useful machine information including the flux plots, components of the air-gap flux density, and the waveforms of voltages and currents. The flux plots obtained clearly demonstrate the effect of armature current on the interpolar flux that helps to improve the voltage regulation. Good agreement between the computed and experimental results has been obtained on a 2.5 kVA prototype generator.

18 citations


"Permanent-Magnet Synchronous Genera..." refers methods in this paper

  • ...In this paper, a time-stepping, coupled field-circuit finite element method [2], [3] is used for performance analysis of a surface-inset PMSG feeding an isolated load....

    [...]

  • ...The time-stepping, coupled field-circuit, 2-D FEA was performed in order to study the steady-state and transient performance of the experimental PMSG with surface-inset rotor [3]....

    [...]

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Q1. What contributions have the authors mentioned in the paper "Permanent-magnet synchronous generator supplying an isolated load" ?

The steady-state and transient performance of a surface-inset permanent-magnet synchronous generator ( PMSG ) feeding an isolated load is studied using a coupled-circuit, timestepping, two-dimensional finite-element analysis. The main contribution of this paper is the quantitative analysis of voltage and current harmonics, as well as the study of short-circuit performance.