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16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
589
Performance Evaluation of Asynchronous Generator Based
Islanded Wind Energy Conversion System
Shailendra Sharma and Bhim Singh
EED, Indian Institute of Technology, Delhi, New Delhi-110016 (India)
[email protected], [email protected]
Abstract—This paper deals with the performance evaluation of a
voltage and frequency controller (VFC) for an isolated
asynchronous generator (IAG) based islanded wind energy
conversion system (IWECS) feeding three-phase four-wire loads.
The control of VFC is based on IcosΦ control algorithm for
extraction of reference source currents. The VFC consists of a
three leg voltage source converter (VSC) with a battery at its dc
bus and a non-isolated star/delta transformer to feed four loads.
The VFC is implemented using a digital signal processor. Test
results are presented to study the performance capabilities of the
proposed VFC for IAG in the wind power generation.
Keywords-Asynchronous
generator,
Battery,
Star-delta
transformer, Voltage source converter, Wind power generation.
C
I.
INTRODUCTION
APACITOR excited Isolated asynchronous generator
(CEIAG) is proved to be prominent generator for the
renewable power generation using wind, hydro and
biomass etc [1]. There are some bottlenecks in its application
as a generator due to its voltage and frequency regulation
characteristics which are non-linear functions of consumer
loads and the prime-mover speed [2]. A number of attempts
have been made to address these problems time to time [3-5].
A satisfactory performance of CEIAG driven by a wind turbine
is reported in [6] with some percentage of unbalanced loading.
However, this study limits the operation of the system for only
partial unbalanced loading.
Further, substantial literature is available on the control of
CEIAG using static power converters in an islanded wind
energy conversion system (IWECS) [7-9]. A stand alone
single-phase induction generator is reported in the literature [8]
in which the supply voltage and frequency are controlled by
single-phase voltage source converter (VSC) and a battery
energy storage (BESS). In [9], simulation results are reported
on the voltage and frequency controller (VFC) with a three
phase CEIAG, feeding three-phase four-wire consumer loads.
However, very rare work is reported on its practical
implementation.
This paper deals with an implementation of VFC based on
IcosΦ algorithm for a CEIAG based IWECS using a digital
signal processor (DSP). A three leg VSC with a battery at its dc
bus is used as a VFC. The star/delta connected transformer is
used with VSC in VFC at point of common coupling (PCC) to
mitigate the neutral current and to provide the neutral terminal
for the distributed single-phase loads. The IcosΦ [10]
algorithm based current detection method is used to extract the
fundamental active and reactive power component of the load
currents. The unit templates sinθ and cosθ are estimated using
phase voltages to compute IWECS frequency. The steady-state
and dynamic performances of VFC are evaluated under
balanced and unbalanced loading of the IWECS.
II.
STUDIED SYSTEM AND PRINCIPLE OF OPERATION
Fig. 1 shows the proposed VFC system for the IWECS. It
shows a CEIAG to feed linear and non-linear consumer loads.
A three leg VSC is used with a BESS as a VFC and it is
connected to the point of common coupling (PCC) through
interface inductors. The VSC provides the reactive power to
CEIAG to regulate the voltage during application of different
kinds of consumer loads. With the BESS at its dc bus, an
active power management takes place by exchanging the
active power under varying input power and consumer loads.
The battery stores the surplus power when the input wind
power is more than the load demand and discharges the deficit
power to common bus when the input wind power goes below
the load demand. The IWECS frequency depends directly on
the instantaneous availability of an input wind power and the
instantaneous load demand. The VSC consists of IGBTs
(Insulated gate bipolar transistors) based three leg VSC
module and a capacitor at its dc bus along with BESS. Each
leg consists of two IGBTs and a common point of each leg is
connected with an individual phase of the generator bus
through an interfacing inductor. In practice majority of small
loads are single phase loads, therefore to take in to
consideration, a three-phase four-wire system is developed in
this IWECS. A non-isolated star-delta transformer is
connected at the PCC to realize the three-phase four-wire
system. The load neutral terminal is provided by the common
terminal of the star-delta transformer primary windings. The
proposed IcosΦ control algorithm is implemented using a
DSP. The VFC implementation requires an appropriate
selection of VSC, a BESS, a dc bus capacitor, an interface
inductor, a scaling circuits for sensing the input signals and
driver circuit for output signals.
Three Hall effect current sensors (ABB EL50 BB) are used
to sense load currents for phase ‘A’, ‘B’ and ‘C’. To sense the
source currents for phase ‘A’ and ‘B’, another set of Hall
effect current sensors (ABB EL50 BB) are used. The
generator is star connected, therefore its third phase source
current is estimated by considering that the algebraic sum of
three phase source currents is zero. Two voltage sensors (LEM
CV3-1500) are used to sense the phase ‘A’ and ‘B’ voltages.
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
590
B
C
vsA
vsB
isA
isB
iLA
iLB
iLC
s1
s3
s5
CP1104(ADC)
dSPACE DSP
Battery
Rack
CP1104 (DAC)
Vbb
Driver Circuit
s1
s4
s3
s6
s5 s2
Fig. 1 System Configration of CEIAG based IWECS
The third phase voltage is estimated considering the algebraic
sum of three phase source voltages is zero. A scaling circuit is
designed to use in between the sensed signals and ADC of
DSP to have a zero offset with the sensed signals. The control
algorithm is realized in MATLAB environment in support
with real time blocks. After compilation, hex codes are loaded
in the dSPACE DSP to generate the switching signals for
IGBT’s through DAC of DSP. An opto-coupler (6N136) based
driver circuit is designed to drive IGBTs of VSC of VFC.
III.
DESIGN OF VOLTAGE AND FREQUENCY CONTROLLER
The proposed VFC for a 3.7 kW, 230V CEIAG consists of
a three-leg in-direct current controlled voltage source
converter (CC-VSC) with the BESS at its dc link. The midpoint of three half bridges are connected individually to each
phase of the generator bus through an inductor. The nonisolated star-delta transformer provides a path for zero
sequence components current present in the loads. It consists
of three single phase transformers with turn ratio of 1:1. For
positive sequence and negative sequence load currents, it
behaves as an open circuit. The current flows in to it only
s4
s6
s2
when zero sequence component present in consumer load
currents. The neutral terminal of the load is connected with
star point of a star-delta transformer. In case of unbalanced
loads, the star-delta transformer provides the path for return
load currents.
A. Excitation Capacitors
The CEIAG requires the reactive power support to build
the rated terminal voltage. The reactive power demand of the
CEIAG is a function of consumer loads connected on the load
bus. Therefore choice of an excitation capacitor affects VSC
rating. In this case the excitation capacitor is selected in such a
way that it delivers the rated terminal voltage at 100% loading
of the machine. The delta connected capacitor bank with 4
kVAR is used in this implementation.
B. DC Bus Voltage
The minimum dc bus voltage of VSC of VFC should be
greater than twice the peak of the phase voltage at the AC
terminals of VSC [11]. The DC bus voltage is calculated as,
(
)
Vdc = 2 2 / 3m VL
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
(1)
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
where m is the modulation index, considered 1 in this case and
VL is the line rms voltage. Thus Vdc is obtained as 376 V for
VL (230 V) and it is selected as 432 V.
C. Selection of Battery
Since the battery is an energy storage unit, its energy is
represented in kilowatt-hours (kWh). As required Vdc is more
than 376V, therefore the minimum battery rack voltage should
be 432V. A battery rack with capacity of 3 kWh is used for
energy storage. For the DC bus voltage of 432 V, 36 units of
12 V, 7Ah are connected in series.
D. AC Inductor
The design of ac inductor depends on permissible current
ripple (icr_pp), DC bus voltage (Vdc) and switching frequency
(fs) of VSC and is given as [11],
3mVdc
Li =
(2)
12af s icr _ PP
where m is the modulation index and a is the overloading
factor. Considering m=1, Vdc=432 V, a=1.2, icr_pp=1.5 % and
fs=10 kHz, the value of Li is obtained as 3.46 mH. A value of 4
mH is selected in this investigation.
IV.
CONTROL SCHEME
As shown in Fig. 2, the control strategy of the proposed
VFC is realized using IcosΦ algorithm for the derivation of
reference source currents. The operation of VFC enforces to
maintain the rated terminal voltage under varying load
conditions and to maintain IWECS frequency along with
balanced and harmonic-free source currents. To achieve this,
the reference source currents need to be controlled through
proper gating of VSC switches. The reference source currents
have two component for each phase, one is active power
component i.e. I.cosφ and other is reactive power component
i.e. I.sinφ. These two components are estimated for each phase
load current. The phase voltages vA and vB are sensed and vC
are estimated from sensed phase voltages. A set of in-phase
(uAp, uBp, uCp) and quadrature unit templates (uAq, uBq, uCq) are
computed using the fundamental phase voltages (filtered using
band pass Butterworth filter). Three phase load currents iLA,
iLB and iLC are sensed and filtered using a 2nd order low pass
Butterworth filter (cutoff frequency 55 Hz) with inherent
phase shift of 900 to extract the amplitude of the fundamental
component of three-phase load currents. A zero crossing
detector (ZCD) is used to detect the negative-going zerocrossing of the corresponding phase voltage. The phaseshifted fundamental current is held as the sample input and
ZCD output pulse is as a hold input to the sample and hold
circuit (SHC) which output is ‘ILp’ as amplitude. The output of
the frequency PI (Proportional-Integral) controller is treated as
‘Ifp’. The average of three-phase active power component of
load currents is derived using the summing amplifier with a
gain (1/3) for the load balancing. The algebraic difference
between the ‘Ifp’ and average of three-phase load currents ‘ILp’
(ILAp, ILBp, ILCp) estimates the amplitude of active power
591
component of the source currents (Ip). Similarly a ZCD is used
to detect the negative-going zero-crossing of the quadrature
template of the respective phase voltage. The phase-shifted
fundamental current is held as the sample input and ZCD
output pulse is as a hold input to the SHC which output is ‘ILq’
as amplitude of reactive power component of the respective
phase current. The average of three-phase reactive power
component of load currents is derived using summing
amplifier with a gain (1/3) for load balancing. The algebraic
difference between the output of the voltage PI regulator ‘Ivq’
and average of three-phase reactive power component of the
load currents ‘ILq’ (ILAq, ILBq, ILCq) computes the amplitude of
the reactive power component of the reference source currents
(Iq). Basic equations of the control algorithm used in the
proposed VFC are as follows.
A. Estimation of IWECS Frequency
The in-phase unit templates are derived using amplitude of
point of common coupling voltage (PCC) Vt and phase
voltages as,
Vt = 2(v A2 + vB2 + vC2 ) / 3
(3)
u Ap = v A / Vt , uBp = vB / Vt , uCp = vC / Vt
(4)
Moreover the quadrature unit template is computed as,
u Aq = (−u Ap + uCp ) / 3,
(5)
u Bq = (u Ap 3 + u Bp − uCp ) / 3,
(6)
u Cq = (−u Ap 3 + uBp − uCp ) / (2 3);
(7)
The in-phase unit templates are in phase with the CEIAG
terminal voltages, so it can be considered as a sinusoidal
function rotating at an angular frequency of the CEIAG
voltage. The quadrature unit template of phase ‘A’ is shifted
from in-phase unit template by an angle of 900, so it can be
treated as a cosine function rotating with a CEIAG angular
frequency.
uAp= sinθ , uBq=cosθ
(8)
The instantaneous value of ‘f’’ is estimated using the in-phase
and quadrature templates for phase ‘A’. The supply frequency
wms in radian/sec can be given as,
wms = cos θ p (sin θ ) − sin θ p(cos θ )
(9)
where p is the time derivative operator and CEIAG frequency
is as f=wms/(2π).
B. Extraction of Amplitude of Fundamental Active Power
Component of Load currents
The amplitudes (ILpA, ILpB, ILpC) of the active power
component of the three-phase consumer load currents are
extracted for phase ‘A’, ‘B’ and ‘C’. These are extracted as the
amplitude of the consumer load currents, phase shifted by
+900, at the negative zero-crossing of the phase voltage. A low
pass Butterworth filter with a cut-off frequency of 55 Hz is
used to shift the load current with an inherent phase shift of
+900. A ZCD is used to detect the negative zero crossing of
the corresponding in-phase unit templates. The phase-shifted
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
amplitude of fundamental active power component of the load
current is held as the sample input and ZCD output is
considered as the hold input to the SHC. The output of SHC is
the ILp. amplitude. The amplitude of three-phase fundamental
active power component of the load currents are as follows,
(10)
I LAp = I LA .cos ϕ A , I LBp = I LB .cos ϕ B , I LCp = I LC .cos ϕC
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reactive power component of the reference source currents.
The ac voltage error at the nth sampling instant is given as,
Ve (n) = Vtr (n) − V (n)
(16)
where φA, φB and φC are the phase angles of the fundamental
currents in A, B and C phases.
C. Extraction of Amplitude of Fundamental Reactive Power
Component of Load currents
The amplitudes (ILqA, ILqB, ILqc) of the reactive power
component of the three-phase consumer load currents are
extracted for phase ‘A’, ‘B’ and ‘C’. These are extracted as the
amplitude of the fundamental load current, phase shifted by
+900, at the negative zero-crossing of the quadrature phase
template. The +900 phase shifted load current is used here. A
ZCD is used to detect the negative zero crossing of the
corresponding quadrature unit templates. The phase-shifted
amplitude of reactive component of the load current is held as
the sample input and ZCD output is considered as the hold
input to the SHC. The output of SHC is the ILq amplitude.
(11)
I LAq = I LA .sin ϕ A , I LBq = I LB .sin ϕ B , I LCq = I LC .sin ϕC
D. Estimation of Active Power Component of Source Currents
The weighted average amplitude of the fundamental active
power component of the consumer load currents is subtracted
from the output of the frequency PI controller to estimate the
amplitude of the active power component of reference source
currents. The frequency error is given as,
f e ( n) = f rf ( n) − f ( n)
(12)
where frf the reference frequency ( i.e. 50 Hz in this case) and
“f” is the frequency of the terminal voltage of an IWECS. The
instantaneous value of “f” is estimated as discussed above in
equation (5).
At the nth sampling instant, the output of the frequency PI
controller is as,
i f p (n) = i fd (n − 1) + k pf { f e (n) − f e (n − 1)} + kif f e (n)
(13)
so the instantaneous value of active power component of
reference source currents (I*P) is as,
(14)
I *p = I fp − I LP
(
)
where I LP = I LAp + I LBp + I LCp / 3
Therefore the fundamental reference active power components
of the source currents for two phases ‘A’ and ‘B’ and ‘C’ are
given as,
*
*
*
isAp
= I * p u Ap , isBp
= I * p u Bp , isCp
= I * p uCp
(15)
E. Reactive Power Component of Reference Source Currents
The weighted average amplitude of the reactive power
component of the load currents is subtracted from the output
of the voltage PI controller to estimate the amplitude of the
Fig. 2 Control Shceme of the proposed Controller
where Vtr(n) is the amplitude of the reference ac terminal
phase voltage and Vt(n) is the amplitude of the sensed three
phase ac voltage.
The output of the voltage PI controller for maintaining a
constant ac terminal voltage at the nth sampling instant is
expressed as,
I vq (n) = I vq (n − 1) + k pa {Ve (n) − Ve (n − 1)} + k piVe (n)
(17)
where kpa and kpi are the proportional and integral gain
constants of the PI controller. Ve(n) and Ve(n-1) are the
voltage errors in the nth and (n-1)th sampling instant and Ivq (n)
and Ivq(n-1) is the output of voltage PI controller in the nth and
(n-1)th instant needed for the voltage control.
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
Therefore the amplitude of fundamental reference reactive
power components of the source current is given as,
(18)
I *q = I vq − I Lq
(
)
where I Lq = I LAq + I LBq + I LCq / 3 ,
593
generated power Pg, load power PL and battery charging power
Pb are shown in Fig. 4 (j-l). However small amount of
generated power is consumed as iron and cu losses takes place
in non-isolated star-delta transformer.
Three-phase fundamental reference reactive power component
of source currents for phase ‘A’ and ‘B’ and ‘C’ are given as,
*
*
*
isAq
= I *q u Aq , isBq
= I *qu Bq , isCq
= I *q uCq
(19)
F. Estimation of Reference Source Currents
Three-phase reference source currents are estimated for each
phase as the vector sum of individual phase fundamental
reference active power component of the source current and
fundamental reference reactive power component of the
source current as,
*
*
*
isA
= i*sAp + i*sAq , isB
= i*sBp + i*sBq , isC
= i*sCp + i*sCq
(20)
G. Current Controller
These three-phase reference source currents (i*sA, i*sB, i*sC)
are compared with sensed source currents (isA, isB, isC). The
independent PWM controllers are used for each leg of threeleg VSC. The resulting current error for each phase is
amplified using a proportional gain and amplified signals are
compared with a fixed frequency (10 kHz) triangular wave to
generate gating signals for the VSC of VFC.
V.
RESULTS AND DISCUSSION
The performance of developed voltage and frequency
controller is tested with linear and nonlinear loads under both
steady-state and dynamic conditions. Load perturbations with
linear loads are made and results are recorded in terms of the
generator line voltage (vAB), generator currents (igA, igB and
igC), source currents (isA, isB and isC), capacitor currents (iCA,
iCB and iCC), star-delta transformer primary currents (iTA, iTB
and iTC) and VSC currents (ivscA, ivscB and ivscC).
A. Performance of VFC With Non-linear Loads
The performance of the VFC is demonstrated with nonlinear loads. A diode bridge rectifier with resistive-inductive
load is chosen as a non-linear load to study the operation of
the controller as a voltage regulator, harmonic eliminator and
as a load leveler. The steady state performance of the
controller is shown in Fig. 3. Test results are recorded with
vAB. The igA, igB and igC are shown with vAB in Figs. 3 (a-c).
The iSA, iSB and iSC along with vAB are shown in Figs. 3 (d-f).
The iCA, iCB and iCC and load currents iLA, iLB and iLC are
recorded with vAB and shown in Figs. 3 (g-l). The VSC
currents ivscA, ivscB and ivscC with vAB are shown in Figs. 4 (a-c).
The load neutral current iLn flowing through star terminal of
non-isolated star-delta transformer is given in Fig. 4 (d). The
non-isolated star-delta transformer primary winding currents
iTA, iTB and iTC with vAB are observed in Figs. 4 (e-g). The
recorded harmonic spectra of generator voltage vA, generator
current igA are shown in Figs. 4 (h-i). The THD’s of generator
current and voltage are well within IEEE- 519 limits. The
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
Fig. 3 Test results of IWECS (a) vAB and igA (b) vAB and igB (c) vAB and igC
(d) vAB and isA (e) vAB and isB (f) vAB and isC (g) vAB and iCA (h) vAB and iCB (i)
vAB and iCC (j) vAB and iLA (k) vAB and iLB (l) vAB and iLC
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
(k)
(l)
Fig. 4 Test results of IWECS (a) vAB and ivscA (b) vAB and ivscB (c) vAB and ivscC
(d) vAB and iLn (e) vAB and iTA (f) vAB and iTB (g) vAB and iTC (h) harmonic
spectrum of vAB (i) harmonic spectrum of igA (j) vAB and Pg (k) vAB and PL (l)
vAB and Pb
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
B. Performance of VFC during Load Removal
Fig. 5 shows the dynamic performance of the controller
during the load removal on phase ‘B’. Test results are
recorded using Agilent make digital oscilloscope
(DSO6014A), voltage differential probe (1/100), current probe
(100mA/V). These waveforms of various test signals are
recorded with vA. Figs. 5(a) shows the three phase source
currents isA, isB and isC during load removal of phase ‘B’.
There is no change in source currents observed during these
conditions. Fig. 5 (b) shows the load currents iLA, iLB and iLC
during the removal of load on phase ‘B’. The dynamic
variation in VSC current ivscA, ivscB and ivscC are observed in
Fig. 5(c). It is clearly seen that during the load removal on
phase ‘B’ leads to necessary change in ivscB magnitude to
absorb the active component of source current towards BESS.
The non-isolated star-delta transformer primary winding
currents iTA, iTB and iTC are recorded in Fig. 5 (d) and are in
consent with the recorded results in Fig. 5 (b) for load
balancing. The dynamic variation in respective phase currents
isB, iLB and ivscB are shown in Fig. 5 (e) during the load
removal on phase ‘B’. To check the variations in battery
current ib during load removal, the results are recorded in Fig.
5 (f).
594
application of phase ‘B’. There is hardly any change in source
current magnitude observed load perturbations. Fig. 6 (b)
shows the load currents iLA, iLB and iLC during the application
of load on phase ‘B’ The dynamic variation in VSC current
ivscA, ivscB and ivscC are observed in Fig. 6(c). It is clearly seen
that applying load on phase ‘B’ leads to necessary reduction in
ivscB magnitude and after load application ivscA, ivscB and ivscC
magnitude are observed identical. The non-isolated star-delta
transformer primary winding currents iTA, iTB and iTC are
recorded in Fig. 6 (d) and are in consent with the recorded
results in Fig. 6 (b). The dynamic variation in respective phase
currents isB, iLB and ivscB are shown in Fig. 6 (e) during the load
application on phase ‘B’. To check the variations in battery
current ib during load removal, the results are recorded in Fig.
6 (f).
VI.
CONCLUSION
The performance of developed VFC for CEIAG based
IWECS has been evaluated under both steady-state and
dynamic conditions. Test results have verified the control
algorithm used for VFC and it performs satisfactory under
both steady state and dynamic conditions. The use of
conventional star-delta transformer has reduced the stress on
(a){ch.1 (75v/div), ch.2-4(5A/div)}
(b) {ch.1 (75v/div), ch.2-4(5A/div)}
( c) {ch.1 (75v/div), ch.2-4(2.5A/div)}
(d) {ch.1 (75v/div), ch.2-4(1.25A/div)}
(e) {ch.1 (75v/div), ch.2-4(2.5A/div)}
(f) {ch.1 (75v/div), ch.2-4(2.5A/div)}
Fig. 5 Test results of IWECS dynamics during load removal (a) vA, isA, isB and isC (b) vA, iLA, iLB and iLC (c) vA, ivscA, ivscB and ivscC (d) vA, iTA, iTB and iTC (e) vA,
isB, iLB and ivscB (f) vA, isB, iLB and ib
C. Performance of VFC during Load Application
Fig. 6 shows the dynamic performance of the controller
during the load application on phase ‘B’. Fig. 6 (a) shows the
three phase source currents isA, isB and isC during load
the VSC for the load balancing which has also facilitated the
IWECS to be used for three-phase four-wire system. The
battery supported VFC has served efficiently for the load
leveling, neutral current compensation and harmonic
elimination.
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
595
(a){ch.1 (75v/div), ch.2-4(5A/div)}
(b) {ch.1 (75v/div), ch.2-4(5A/div)}
( c) {ch.1 (75v/div), ch.2-4(2.5A/div)}
(d) {ch.1 (75v/div), ch.2-4(1.25A/div)}
(e) {ch.1 (75v/div), ch.2-4(2.5A/div)}
(f) {ch.1 (75v/div), ch.2-4(2.5A/div)}
Fig. 6 Test results of IWECS dynamics during load application (a) vA, isA, isB and isC (b) vA, iLA, iLB and iLC (c) vA, ivscA, ivscB and ivscC (d) vA, iTA, iTB and iTC (e) vA,
isB, iLB and ivscB (f) vA, isB, iLB and ib
[6]
APPENDIX
IAG Data
3.7 kW, 230 V, 14.5 A, 50 Hz, Y- Connected, 4Pole
Prime-Mover
Data
3.7 kW, 415 V, 7A, ∆-connected, 4-pole, 1430
rpm, induction motor driven by ABB make AC
Drive ACS 550-01-015A
Ready to shelf semikron make voltage source
converter 25kVA, Lf=4 mH, Rf= 0.01 Ω,
Cdc=4000 µF, Kpav=2, Kaiv=0.05, Kpaf=2,
Kpif=0.8
Vdc=432V, 3kWh, 36 units of 12 V , 7Ah
connected in series
1 kVA Three phase transformer with each phase
having two windings with 133V ratings
VFC Parameters
Battery Rack
Star /delta
Transformer
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Shailendra Sharma was born in Indore, India, in 1972.
He received his M.E. in Electrical Engineering with
specialization in power electronics in 2004 from the
Shri Govindram Seksaria Institute of Technology and
Science, Indore, India. He has five years of industrial
experience as an erection and commissioning engineer.
He joined the Department of Electrical Engineering,
Shri GSITS, Indore in 2004 as a Lecturer. Presently, he
is pursuing research at Indian Institute of Technology, Delhi, India, under the
Quality Improvement Programme. His fields of interest include power
electronics, drives, power quality, and renewable energy. He is Associate
Member of the Institution of Engineers India.
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.
16th NATIONAL POWER SYSTEMS CONFERENCE, 15th-17th DECEMBER, 2010
Bhim Singh was born in Rahamapur, India, in 1956. He
received his B.E. from the University of Roorkee,
Roorkee, India, in 1977 and his M.Tech and Ph.D. from
the Indian Institute of Technology (IIT) Delhi, New
Delhi, India, in 1979 and 1983, respectively. In 1983, he
joined the Department of Electrical Engineering,
University of Roorkee, as a Lecturer, and in 1988 he
became a Reader. In December 1990, he joined the
Department of Electrical Engineering, IIT Delhi, as an Assistant Professor. He
became an Associate Professor in 1994 and a Professor in 1997. His areas of
596
interest include power electronics, electrical machines and drives, active
filters, FACTS, HVDC and power quality. He is a Fellow of the Indian
National Academy of Engineering (INAE), the National Science Academy
(FNSc), the Institution of Engineers (India) (IE(I)), and the Institution of
Electronics and Telecommunication Engineers (IETE). He is also a life
member of the Indian Society for Technical Education (ISTE), the System
Society of India (SSI), and the National Institution of Quality and Reliability
(NIQR). In addition he is a Fellow of the Institute of Electrical and Electronics
Engineers (IEEE).
Department of Electrical Engineering, Univ. College of Engg., Osmania University, Hyderabad, A.P, INDIA.