SlideShare a Scribd company logo
1 of 9
Download to read offline
IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011 307
Grid Interconnection of Renewable
Energy Sources at the Distribution Level
With Power-Quality Improvement Features
Mukhtiar Singh, Student Member, IEEE, Vinod Khadkikar, Member, IEEE, Ambrish Chandra, Senior Member, IEEE,
and Rajiv K. Varma, Senior Member, IEEE
Abstract—Renewable energy resources (RES) are being increas-
ingly connected in distribution systems utilizing power electronic
converters. This paper presents a novel control strategy for
achieving maximum benefits from these grid-interfacing inverters
when installed in 3-phase 4-wire distribution systems. The inverter
is controlled to perform as a multi-function device by incorpo-
rating active power filter functionality. The inverter can thus be
utilized as: 1) power converter to inject power generated from
RES to the grid, and 2) shunt APF to compensate current unbal-
ance, load current harmonics, load reactive power demand and
load neutral current. All of these functions may be accomplished
either individually or simultaneously. With such a control, the
combination of grid-interfacing inverter and the 3-phase 4-wire
linear/non-linear unbalanced load at point of common coupling
appears as balanced linear load to the grid. This new control
concept is demonstrated with extensive MATLAB/Simulink simu-
lation studies and validated through digital signal processor-based
laboratory experimental results.
Index Terms—Active power filter (APF), distributed generation
(DG), distribution system, grid interconnection, power quality
(PQ), renewable energy.
I. INTRODUCTION
ELECTRIC utilities and end users of electric power are
becoming increasingly concerned about meeting the
growing energy demand. Seventy five percent of total global
energy demand is supplied by the burning of fossil fuels. But
increasing air pollution, global warming concerns, diminishing
fossil fuels and their increasing cost have made it necessary
to look towards renewable sources as a future energy solution.
Since the past decade, there has been an enormous interest in
many countries on renewable energy for power generation. The
market liberalization and government’s incentives have further
accelerated the renewable energy sector growth.
Manuscript received March 15, 2009; revised July 04, 2010; accepted August
19, 2010. Date of publication November 01, 2010; date of current version De-
cember 27, 2010. Paper no. TPWRD-00216-2009.
M. Singh and A. Chandra are with the Department of Electrical Engineering,
Ecole de technologie superieure, Montreal, QC H3C 1K3, Canada (e-mail:
smukhtiar_79@yahoo.co.in; ambrish.chandra@etsmtl.ca).
V. Khadkikar is with the Electrical Power Engineering Program, Masdar In-
stitute, Abu Dhabi, United Arab Emirates (e-mail: vkhadkikar@masdar.ac.ae).
R. K. Varma is with the Department of Electrical and Computer Engineering,
University of Western Ontario, London, ON N6A 5B8, Canada (e-mail:
rkvarma@uwo.ca).
Color versions of one or more of the figures in this paper are available online
at http://ieeexplore.ieee.org.
Digital Object Identifier 10.1109/TPWRD.2010.2081384
Renewable energy source (RES) integrated at distribution
level is termed as distributed generation (DG). The utility is
concerned due to the high penetration level of intermittent RES
in distribution systems as it may pose a threat to network in
terms of stability, voltage regulation and power-quality (PQ)
issues. Therefore, the DG systems are required to comply
with strict technical and regulatory frameworks to ensure safe,
reliable and efficient operation of overall network. With the ad-
vancement in power electronics and digital control technology,
the DG systems can now be actively controlled to enhance
the system operation with improved PQ at PCC. However,
the extensive use of power electronics based equipment and
non-linear loads at PCC generate harmonic currents, which
may deteriorate the quality of power [1], [2].
Generally, current controlled voltage source inverters are
used to interface the intermittent RES in distributed system.
Recently, a few control strategies for grid connected inverters
incorporating PQ solution have been proposed. In [3] an inverter
operates as active inductor at a certain frequency to absorb
the harmonic current. But the exact calculation of network
inductance in real-time is difficult and may deteriorate the con-
trol performance. A similar approach in which a shunt active
filter acts as active conductance to damp out the harmonics
in distribution network is proposed in [4]. In [5], a control
strategy for renewable interfacing inverter based on - theory
is proposed. In this strategy both load and inverter current
sensing is required to compensate the load current harmonics.
The non-linear load current harmonics may result in voltage
harmonics and can create a serious PQ problem in the power
system network. Active power filters (APF) are extensively used
to compensate the load current harmonics and load unbalance
at distribution level. This results in an additional hardware cost.
However, in this paper authors have incorporated the features of
APF in the, conventional inverter interfacing renewable with the
grid, without any additional hardware cost. Here, the main idea
is the maximum utilization of inverter rating which is most of the
time underutilized due to intermittent nature of RES. It is shown
in this paper that the grid-interfacing inverter can effectively be
utilized to perform following important functions: 1) transfer
of active power harvested from the renewable resources (wind,
solar, etc.); 2) load reactive power demand support; 3) current
harmonics compensation at PCC; and 4) current unbalance and
neutral current compensation in case of 3-phase 4-wire system.
Moreover, with adequate control of grid-interfacing inverter, all
the four objectives can be accomplished either individually or
simultaneously. The PQ constraints at the PCC can therefore
be strictly maintained within the utility standards without addi-
tional hardware cost.
0885-8977/$26.00 © 2010 IEEE
308 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011
Fig. 1. Schematic of proposed renewable based distributed generation system.
The paper is arranged as follows: Section II describes the
system under consideration and the controller for grid-in-
terfacing inverter. A digital simulation study is presented in
Section III. Extensive experimental results are discussed in
Section IV and, finally, Section V concludes the paper.
II. SYSTEM DESCRIPTION
The proposed system consists of RES connected to the
dc-link of a grid-interfacing inverter as shown in Fig. 1. The
voltage source inverter is a key element of a DG system as it
interfaces the renewable energy source to the grid and delivers
the generated power. The RES may be a DC source or an AC
source with rectifier coupled to dc-link. Usually, the fuel cell
and photovoltaic energy sources generate power at variable low
dc voltage, while the variable speed wind turbines generate
power at variable ac voltage. Thus, the power generated from
these renewable sources needs power conditioning (i.e., dc/dc
or ac/dc) before connecting on dc-link [6]–[8]. The dc-capac-
itor decouples the RES from grid and also allows independent
control of converters on either side of dc-link.
A. DC-Link Voltage and Power Control Operation
Due to the intermittent nature of RES, the generated power is
of variable nature. The dc-link plays an important role in trans-
ferring this variable power from renewable energy source to the
grid. RES are represented as current sources connected to the
dc-link of a grid-interfacing inverter. Fig. 2 shows the system-
atic representation of power transfer from the renewable energy
resources to the grid via the dc-link. The current injected by re-
newable into dc-link at voltage level can be given as
(1)
where is the power generated from RES.
Fig. 2. DC-Link equivalent diagram.
The current flow on the other side of dc-link can be repre-
sented as,
(2)
where and are total power available at grid-in-
terfacing inverter side, active power supplied to the grid and in-
verter losses, respectively. If inverter losses are negligible then
.
B. Control of Grid Interfacing Inverter
The control diagram of grid- interfacing inverter for a 3-phase
4-wire system is shown in Fig. 3. The fourth leg of inverter is
used to compensate the neutral current of load. The main aim
of proposed approach is to regulate the power at PCC during:
1) ; 2) ; and 3)
. While performing the power management oper-
ation, the inverter is actively controlled in such a way that it
always draws/ supplies fundamental active power from/ to the
grid. If the load connected to the PCC is non-linear or unbal-
anced or the combination of both, the given control approach
also compensates the harmonics, unbalance, and neutral current.
The duty ratio of inverter switches are varied in a power cycle
such that the combination of load and inverter injected power
SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 309
Fig. 3. Block diagram representation of grid-interfacing inverter control.
appears as balanced resistive load to the grid. The regulation of
dc-link voltage carries the information regarding the exchange
of active power in between renewable source and grid. Thus the
output of dc-link voltage regulator results in an active current
. The multiplication of active current component with
unity grid voltage vector templates ( , and ) generates
the reference grid currents ( , and ). The reference grid
neutral current is set to zero, being the instantaneous sum
of balanced grid currents. The grid synchronizing angle ob-
tained from phase locked loop (PLL) is used to generate unity
vector template as [9]–[11]
(3)
(4)
(5)
The actual dc-link voltage is sensed and passed through
a first-order low pass filter (LPF) to eliminate the presence of
switching ripples on the dc-link voltage and in the generated
reference current signals. The difference of this filtered dc-link
voltage and reference dc-link voltage is given to a dis-
crete-PI regulator to maintain a constant dc-link voltage under
varying generation and load conditions. The dc-link voltage
error at th sampling instant is given as:
(6)
The output of discrete-PI regulator at th sampling instant is
expressed as
(7)
where and are proportional and
integral gains of dc-voltage regulator. The instantaneous values
of reference three phase grid currents are computed as
(8)
(9)
(10)
The neutral current, present if any, due to the loads connected
to the neutral conductor should be compensated by forth leg of
grid-interfacing inverter and thus should not be drawn from the
grid. In other words, the reference current for the grid neutral
current is considered as zero and can be expressed as
(11)
The reference grid currents ( and ) are compared
with actual grid currents ( and ) to compute the cur-
rent errors as
(12)
(13)
(14)
(15)
These current errors are given to hysteresis current controller.
The hysteresis controller then generates the switching pulses
( to ) for the gate drives of grid-interfacing inverter.
The average model of 4-leg inverter can be obtained by the
following state space equations
(16)
(17)
310 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011
(18)
(19)
(20)
where , and are the three-phase ac
switching voltages generated on the output terminal of inverter.
These inverter output voltages can be modeled in terms of in-
stantaneous dc bus voltage and switching pulses of the inverter
as
(21)
(22)
(23)
(24)
Similarly the charging currents , and
on dc bus due to the each leg of inverter can be expressed
as
(25)
(26)
(27)
(28)
The switching pattern of each IGBT inside inverter can be for-
mulated on the basis of error between actual and reference cur-
rent of inverter, which can be explained as:
If , then upper switch will be OFF
and lower switch will be ON in the
phase “a” leg of inverter.
If , then upper switch will be ON
and lower switch will be OFF in
the phase “a” leg of inverter.
where is the width of hysteresis band. On the same principle,
the switching pulses for the other remaining three legs can be
derived.
III. SIMULATION RESULTS
In order to verify the proposed control approach to achieve
multi-objectives for grid interfaced DG systems connected
to a 3-phase 4-wire network, an extensive simulation study
is carried out using MATLAB/Simulink. A 4-leg current
controlled voltage source inverter is actively controlled to
achieve balanced sinusoidal grid currents at unity power factor
(UPF) despite of highly unbalanced nonlinear load at PCC
under varying renewable generating conditions. A RES with
variable output power is connected on the dc-link of grid-in-
terfacing inverter. An unbalanced 3-phase 4-wire nonlinear
load, whose unbalance, harmonics, and reactive power need
to be compensated, is connected on PCC. The waveforms of
Fig. 4. Simulation results: (a) Grid voltages, (b) Grid Currents (c) Unbalanced
load currents, (d) Inverter Currents.
grid voltage , grid currents ( ), un-
balanced load current and inverter currents
are shown in Fig. 4. The corre-
sponding active-reactive powers of grid , load
and inverter are shown in Fig. 5.
Positive values of grid active-reactive powers and inverter
active-reactive powers imply that these powers flow from grid
side towards PCC and from inverter towards PCC, respectively.
The active and reactive powers absorbed by the load are denoted
by positive signs.
Initially, the grid-interfacing inverter is not connected to the
network (i.e., the load power demand is totally supplied by the
grid alone). Therefore, before time s, the grid cur-
rent profile in Fig. 4(b) is identical to the load current profile
of Fig. 4(c). At s, the grid-interfacing inverter is con-
nected to the network. At this instant the inverter starts injecting
the current in such a way that the profile of grid current starts
changing from unbalanced non linear to balanced sinusoidal
current as shown in Fig. 4(b). As the inverter also supplies the
SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 311
Fig. 5. Simulation results: (a) PQ-Grid, (b) PQ-Load, (c) PQ-Inverter,
(d) dc-link voltage.
load neutral current demand, the grid neutral current be-
comes zero after s.
At s, the inverter starts injecting active power gen-
erated from RES . Since the generated power is
more than the load power demand the additional power is fed
back to the grid. The negative sign of , after time 0.72 s
suggests that the grid is now receiving power from RES. More-
over, the grid-interfacing inverter also supplies the load reactive
power demand locally. Thus, once the inverter is in operation
the grid only supplies/receives fundamental active power.
At s, the active power from RES is increased to
evaluate the performance of system under variable power gener-
ation from RES. This results in increased magnitude of inverter
current. As the load power demand is considered as constant,
this additional power generated from RES flows towards grid,
which can be noticed from the increased magnitude of grid cur-
rent as indicated by its profile. At s, the power available
from RES is reduced. The corresponding change in the inverter
and grid currents can be seen from Fig. 4. The active and re-
active power flows between the inverter, load and grid during
increase and decrease of energy generation from RES can be
noticed from Fig. 5. The dc-link voltage across the grid- inter-
facing inverter (Fig. 5(d)) during different operating condition is
maintained at constant level in order to facilitate the active and
reactive power flow. Thus from the simulation results, it is evi-
dent that the grid-interfacing inverter can be effectively used to
compensate the load reactive power, current unbalance and cur-
rent harmonics in addition to active power injection from RES.
This enables the grid to supply/ receive sinusoidal and balanced
power at UPF.
IV. EXPERIMENTAL VALIDATION
The performance of the proposed control approach is vali-
dated with the help of a scaled laboratory prototype that has
system parameters as given in Table I. The RES is emulated
TABLE I
SYSTEM PARAMETER
using an auxiliary controlled converter, which injects varying
active power at the dc-link of an insulated gate bipolar transistor
(IGBT) based 4-leg voltage source inverter connected to grid. A
3-phase 4-wire nonlinear load, composed of 3-phase non-linear
balanced load, 1-phase R-L load between phase and neutral
and 1-phase non-linear load between phase and neutral, is con-
nected to the grid. The total harmonics distortions (THDs) of
phase and load currents are noticed as 14.21%, 22.93%,
and 16.21%, respectively. The DS1104® DSP of dSPACE is uti-
lized to generate the reference grid current signals in real-time.
The difference of reference and actual grid current signals is
applied to external hysteresis board to generate the gate pulses
for IGBT’s. The proposed control approach requires a sam-
pling time of 75 s to execute the MATLAB/Simulink gener-
ated C-codes in real-time.
The experimental results are divided into three different
modes of operation in order to highlight the validity of pro-
posed controller. First mode of operation considers a situation
when there is no power generation from RES. Under such
condition, the grid-interfacing inverter is utilized as shunt APF
to enhance the quality of power at PCC. While in second mode
of operation, the inverter injects RES active power into grid
and also incorporates the active power filtering functionality. In
the third mode, the dynamic operation of proposed controller
is examined. The experimental results are given in Figs. 6–10.
All the voltage and current waveforms are captured utilizing an
oscilloscope, whereas, the active and reactive powers are cap-
tured in real-time using ControlDesk Developer environment.
A. Mode of Operation—PQ Enhancement
Fig. 6 shows the experimental results for active power fil-
tering mode of operation when there is no power generation
from RES. All the current waveforms are shown with respec-
tive to grid side phase voltage . Fig. 6(a) shows the profile
of the unbalance non-linear load currents. The grid current pro-
file, when grid-interfacing inverter controlled as shunt APF, is
shown in Fig. 6(b). It can be noticed that the highly unbalanced
load currents, after compensation, appear as pure sinusoidal bal-
anced set of currents on grid side. The grid current THD’s are
reduced to 2.36%, 1.68%, 3.65% for and phases, respec-
tively. In Fig. 6(c), the compensating inverter currents are shown
for each phase along with dc-link voltage. For the experimental
study, the dc-link voltage is maintained at 100 V. Fig. 6(d) shows
the traces for neutral current of grid, load and inverter. The load
neutral current due to single-phase loads is effectively compen-
sated by the 4th leg of inverter such that the current in grid side
neutral conductor is reduced to zero.
312 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011
Fig. 6. Experimental results for the active power filtering mode (P = 0): (a) unbalanced load currents, (b) grid currents after compensation, (c) currents
injected by grid-interfacing inverter, (d) load, grid and inverter neutral currents.
Fig. 7. Experimental results for the active power filtering mode (P = 0): active and reactive power flow in real-time.
SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 313
Fig. 8. Experimental results for the active power filtering and renewable power injection mode (P > P ): (a) phase aperformance, (b) phase bperformance,
(c) phase c performance, (d) grid currents (e) load, grid and inverter neutral currents.
Fig. 7 shows the total active and reactive powers of grid, load
and inverter. In the APF mode of operation, the inverter con-
sumes a small amount of active power to maintain the dc-link
voltage and to overcome the losses associated with inverter,
while most of the load reactive power need is supported by in-
verter effectively. Thus, this mode of operation validates the
concept of utilization of grid-interfacing inverter as shunt APF
when there is no power generation from the RES. The experi-
mental results demonstrate the effective compensations of load
current unbalance, harmonics and reactive power.
B. Mode of Operation—Simultaneous PQ Enhancement and
RES Power Injection
The experimental results for simultaneous active power fil-
tering and RES power injection mode are shown in Fig. 8. In this
case study it is considered that the generated power at grid-in-
terfacing inverter is more than the total load power demand.
Therefore, after meeting the load power demand, the additional
RES power flows towards grid. The profiles of grid, load and
inverter currents for individual phases are shown in Figs. 8(a),
(b) & (c) for phase and , respectively. As noticed from
Fig. 8(a) to (c), the inverter currents consist of two compo-
nents: 1) steady-state load current component and 2) grid active
power injection component. Thus the grid-interfacing inverter
now provides the entire load power demand (active, reactive
and harmonics) locally and feeds the additional active power
(sinusoidal and balanced) to the grid. The exact out-of phase
relationship between phase— grid voltage and phase— grid
current suggests that this additional power is fed to the grid at
UPF. The three-phase grid currents (Fig. 8(d)) suggest that the
injected active power from RES to the grid is supplied as bal-
anced active power even the load on the system is unbalanced
in nature. During both mode of operation, as the load on the
system is considered constant, the load neutral current profile
and its compensation is identical to the one already discussed in
previous subsection and can also be noticed from Figs. 6(d) and
8(e).
The exchange of total active and reactive powers between
grid, load and inverter are shown in Fig. 9. The negative sign of
total grid side active power demonstrates that the excess power
generated by RES flows towards grid side. Thus, this case study
demonstrates that the grid-interfacing inverter can simultane-
ously be utilized to inject power generated from RES to PCC and
to improve the quality of power (current unbalance compensa-
tion, current harmonics compensation, load reactive power sup-
port, neutral current compensation) at PCC.
314 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011
Fig. 9. Experimental results for the active power filtering and renewable power injection mode (P > P ): active and reactive power flow in real time.
Fig. 10. Experimental results: Dynamic performance of proposed approach.
C. Dynamic Performance of Proposed Control Approach
Fig. 10 shows the experimental results to validate the
dynamic performance of proposed control approach under
different modes of operation. Initially, it is considered that the
system is working under mode-A operating condition (i.e.,
non-linear load current harmonics and reactive power com-
pensation). After few cycles, the power at dc-link is initially
increased and then decreased, which can be noticed from
the amplitude of injected inverter current profile. The corre-
sponding decrease (for increased power level at dc-link) and
increase (for decreased power level at dc-link) in grid current
magnitude can also be noticed from Fig. 10, under constant load
conditions. Thus, the proposed controller precisely manages
any variation in real power at dc-link and effectively feeds it to
the main grid. A smooth changeover from mode-A operating
condition to the mode-B can be noticed from Fig. 10.
V. CONCLUSION
This paper has presented a novel control of an existing grid-
interfacing inverter to improve the quality of power at PCC for a
3-phase 4-wire DG system. It has been shown that the grid-inter-
facing inverter can be effectively utilized for power conditioning
without affecting its normal operation of real power transfer.
The grid-interfacing inverter with the proposed approach can be
utilized to:
i) inject real power generated from RES to the grid, and/or,
ii) operate as a shunt Active Power Filter (APF).
This approach thus eliminates the need for additional power
conditioning equipment to improve the quality of power at
PCC. Extensive MATLAB/Simulink simulation as well as the
DSP based experimental results have validated the proposed
approach and have shown that the grid-interfacing inverter can
be utilized as a multi-function device.
It is further demonstrated that the PQ enhancement can be
achieved under three different scenarios: 1) , 2)
, and 3) . The current unbalance,
current harmonics and load reactive power, due to unbalanced
and non-linear load connected to the PCC, are compensated ef-
fectively such that the grid side currents are always maintained
as balanced and sinusoidal at unity power factor. Moreover,
the load neutral current is prevented from flowing into the
grid side by compensating it locally from the fourth leg of
inverter. When the power generated from RES is more than the
total load power demand, the grid-interfacing inverter with the
proposed control approach not only fulfills the total load active
and reactive power demand (with harmonic compensation) but
also delivers the excess generated sinusoidal active power to
the grid at unity power factor.
SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 315
REFERENCES
[1] J. M. Guerrero, L. G. de Vicuna, J. Matas, M. Castilla, and J. Miret,
“A wireless controller to enhance dynamic performance of parallel in-
verters in distributed generation systems,” IEEE Trans. Power Elec-
tron., vol. 19, no. 5, pp. 1205–1213, Sep. 2004.
[2] J. H. R. Enslin and P. J. M. Heskes, “Harmonic interaction between
a large number of distributed power inverters and the distribution net-
work,” IEEE Trans. Power Electron., vol. 19, no. 6, pp. 1586–1593,
Nov. 2004.
[3] U. Borup, F. Blaabjerg, and P. N. Enjeti, “Sharing of nonlinear load
in parallel-connected three-phase converters,” IEEE Trans. Ind. Appl.,
vol. 37, no. 6, pp. 1817–1823, Nov./Dec. 2001.
[4] P. Jintakosonwit, H. Fujita, H. Akagi, and S. Ogasawara, “Implemen-
tation and performance of cooperative control of shunt active filters
for harmonic damping throughout a power distribution system,” IEEE
Trans. Ind. Appl., vol. 39, no. 2, pp. 556–564, Mar./Apr. 2003.
[5] J. P. Pinto, R. Pregitzer, L. F. C. Monteiro, and J. L. Afonso, “3-phase
4-wire shunt active power filter with renewable energy interface,” pre-
sented at the Conf. IEEE Rnewable Energy & Power Quality, Seville,
Spain, 2007.
[6] F. Blaabjerg, R. Teodorescu, M. Liserre, and A. V. Timbus, “Overview
of control and grid synchronization for distributed power generation
systems,” IEEE Trans. Ind. Electron., vol. 53, no. 5, pp. 1398–1409,
Oct. 2006.
[7] J. M. Carrasco, L. G. Franquelo, J. T. Bialasiewicz, E. Galván, R. C.
P. Guisado, M. Á. M. Prats, J. I. León, and N. M. Alfonso, “Power-
electronic systems for the grid integration of renewable energy sources:
A survey,” IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1002–1016,
Aug. 2006.
[8] B. Renders, K. De Gusseme, W. R. Ryckaert, K. Stockman, L. Van-
develde, and M. H. J. Bollen, “Distributed generation for mitigating
voltage dips in low-voltage distribution grids,” IEEE Trans. Power.
Del., vol. 23, no. 3, pp. 1581–1588, Jul. 2008.
[9] V. Khadkikar, A. Chandra, A. O. Barry, and T. D. Nguyen, “Appli-
cation of UPQC to protect a sensitive load on a polluted distribution
network,” in Proc. Annu. Conf. IEEE Power Eng. Soc. Gen. Meeting,
2006, pp. 867–872.
[10] M. Singh and A. Chandra, “Power maximization and voltage sag/swell
ride-through capability of PMSG based variable speed wind energy
conversion system,” in Proc. IEEE 34th Annu. Conf. Indus. Electron.
Soc., 2008, pp. 2206–2211.
[11] P. Rodríguez, J. Pou, J. Bergas, J. I. Candela, R. P. Burgos, and D.
Boroyevich, “Decoupled double synchronous reference frame PLL for
power converters control,” IEEE Trans. Power Electron, vol. 22, no. 2,
pp. 584–592, Mar. 2007.
Mukhtiar Singh (S’08) received the B.Tech. and
M.Tech. degrees in electrical engineering from the
National Institute of Technology (formerly known
as R.E.C. Kurukshetra), Kurukshetra, India, in 1999
and 2001, respectively, and is currently pursuing the
Ph.D. degree at Ecole de Technologie Superieure,
Universite du Quebec, Montreal, QC, Canada, under
the National Overseas Scholarship, funded by the
Government of India.
He was a faculty member at B.M.I.E.T., Sonepat,
India, and K.I.E.T., Ghaziabad, India, during
2000–2002. Since 2002, he has been an Assistant Professor in the Department
of Electrical Engineering, Deenbandhu Chhoturam University of Science and
Technology, Sonepat, India. Currently, he is on study leave. His research
interests include renewable energy sources, power quality, energy storage
systems, electric vehicles, and power electronics and drives.
Vinod Khadkikar (S’06–M’09) received the B.E.
degree in electrical engineering from the Gov-
ernment College of Engineering, Dr. B. A. M. U.
University, Aurangabad, India, in 2000, the M.Tech.
degree in electrical engineering from the Indian
Institute of Technology (I.I.T.), New Delhi, India, in
2002, and the Ph.D. degrees in electrical engineering
from the École de Technologie Supérieure (E.T.S.),
Montréal, QC, Canada, in 2008.
From 2008 to 2010, he was a Postdoctoral Fellow
at the University of Western Ontario, London, ON,
Canada. Since 2010, he has been an Assistant Professor at Masdar Institute, Abu
Dhabi, United Arab Emirates. Currently, he is with the visiting faculty at the
Massachusetts Institute of Technology, Cambridge, MA. His research interests
include applications of power electronics in distribution systems, power-quality
enhancement, active power filters, applications of power electronics in renew-
able energy resources, and grid interconnection issues.
Ambrish Chandra (SM’99) was born in India
in 1955. He received the B.E. degree from the
University of Roorkee, India, in 1977, the M.Tech.
degree from the Indian Institute of Technology, New
Delhi, India, in 1980, and the Ph.D. degree from
the University of Calgary, Calgary, AB, Canada, in
1987.
He was a Lecturer and then a Reader at the
University of Roorkee. Since 1994, he has been a
Professor in the Electrical Engineering Department
at École de Technologie Supérieure, Universié du
Québec, Montréal, Canada. His main research interests are power quality,
active filters, static reactive power compensation, flexible ac transmission
systems, and power-quality issues related to autonomous and grid–connected
renewable energy resources.
Dr. Chandra is a member of the Ordre des Ingénieurs du Québec, Canada.
Rajiv K. Varma (SM’96) received the B.Tech. and
Ph.D. degrees in electrical engineering from the In-
dian Institute of Technology (IIT), Kanpur, India, in
1980 and 1988, respectively.
Currently, he is an Associate Professor at the
University of Western Ontario (UWO), London,
ON, Canada. Prior to this position, he was a faculty
member in the Electrical Engineering Department
at the Indian Institute of Technology, Kanpur, India,
from 1989 to 2001. While in India, he was awarded
the Government of India BOYSCAST Young Scien-
tist Fellowship in 1992–1993 to conduct research on flexible ac transmission
systems (FACTS) at the UWO. His research interests include FACTS, power
systems stability, and grid integration of wind and photovoltaic solar power
systems.
Dr. Varma received the Fulbright Grant of the U.S. Educational Foundation
in India to conduct research in FACTS at the Bonneville Power Administration,
Portland, OR, during 1998. He is the Chair of IEEE Working Group on “FACTS
and HVDC Bibliography” and is active on a number of other IEEE working
groups. He has received several Teaching Excellence awards at the Faculty of
Engineering and University level at UWO.

More Related Content

What's hot

Challenges and Benefits of Integrating the Renewable Energy Technologies into...
Challenges and Benefits of Integrating the Renewable Energy Technologies into...Challenges and Benefits of Integrating the Renewable Energy Technologies into...
Challenges and Benefits of Integrating the Renewable Energy Technologies into...Power System Operation
 
Large Scale Grid Integration of Renewable Energy Sources - Way Forward
Large Scale Grid Integration of Renewable Energy Sources - Way ForwardLarge Scale Grid Integration of Renewable Energy Sources - Way Forward
Large Scale Grid Integration of Renewable Energy Sources - Way ForwardSpark Network
 
seminar report on optimal placement and optimal sizing of DG
seminar report on optimal placement and optimal sizing of DGseminar report on optimal placement and optimal sizing of DG
seminar report on optimal placement and optimal sizing of DGkhemraj298
 
Renewable Integration & Energy Strage Smart Grid Pilot Project
Renewable Integration & Energy Strage Smart Grid Pilot ProjectRenewable Integration & Energy Strage Smart Grid Pilot Project
Renewable Integration & Energy Strage Smart Grid Pilot ProjectPartha Deb
 
Grid Integration of Renewables: Challenges and Solutions
Grid Integration of Renewables: Challenges and SolutionsGrid Integration of Renewables: Challenges and Solutions
Grid Integration of Renewables: Challenges and SolutionsPower System Operation
 
Optimal Placement of Distributed Generation on Radial Distribution System for...
Optimal Placement of Distributed Generation on Radial Distribution System for...Optimal Placement of Distributed Generation on Radial Distribution System for...
Optimal Placement of Distributed Generation on Radial Distribution System for...IJMER
 
A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...
A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...
A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...IJERD Editor
 
Grid integration of renewable energy-Priyabrata Patnaik
Grid integration of renewable energy-Priyabrata PatnaikGrid integration of renewable energy-Priyabrata Patnaik
Grid integration of renewable energy-Priyabrata PatnaikDr.Priyabrata Patnaik
 
Integration of Renewable Energy In Grid
Integration of Renewable Energy In GridIntegration of Renewable Energy In Grid
Integration of Renewable Energy In GridTejaswi Shukla
 
A grid connected dual voltage source inverter with power quality improvement ...
A grid connected dual voltage source inverter with power quality improvement ...A grid connected dual voltage source inverter with power quality improvement ...
A grid connected dual voltage source inverter with power quality improvement ...LeMeniz Infotech
 
OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...
OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...
OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...Prashanta Sarkar
 
Renewable energy and grid integration energy transition
Renewable energy and grid integration   energy transitionRenewable energy and grid integration   energy transition
Renewable energy and grid integration energy transitionNarinporn Malasri
 
Distributed generation placement
Distributed generation placementDistributed generation placement
Distributed generation placementreza shahbazi
 
Optimal placement of distributed power flow controller for loss reduction usi...
Optimal placement of distributed power flow controller for loss reduction usi...Optimal placement of distributed power flow controller for loss reduction usi...
Optimal placement of distributed power flow controller for loss reduction usi...eSAT Journals
 
Droop control method for parallel dc converters used in standalone pv wind po...
Droop control method for parallel dc converters used in standalone pv wind po...Droop control method for parallel dc converters used in standalone pv wind po...
Droop control method for parallel dc converters used in standalone pv wind po...eSAT Journals
 
What is Distributed Generation
What is Distributed GenerationWhat is Distributed Generation
What is Distributed GenerationAjay Singh
 
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...ijtsrd
 

What's hot (20)

Challenges and Benefits of Integrating the Renewable Energy Technologies into...
Challenges and Benefits of Integrating the Renewable Energy Technologies into...Challenges and Benefits of Integrating the Renewable Energy Technologies into...
Challenges and Benefits of Integrating the Renewable Energy Technologies into...
 
Impacts of Photovoltaic Distributed Generation Location and Size on Distribut...
Impacts of Photovoltaic Distributed Generation Location and Size on Distribut...Impacts of Photovoltaic Distributed Generation Location and Size on Distribut...
Impacts of Photovoltaic Distributed Generation Location and Size on Distribut...
 
Large Scale Grid Integration of Renewable Energy Sources - Way Forward
Large Scale Grid Integration of Renewable Energy Sources - Way ForwardLarge Scale Grid Integration of Renewable Energy Sources - Way Forward
Large Scale Grid Integration of Renewable Energy Sources - Way Forward
 
seminar report on optimal placement and optimal sizing of DG
seminar report on optimal placement and optimal sizing of DGseminar report on optimal placement and optimal sizing of DG
seminar report on optimal placement and optimal sizing of DG
 
Renewable Integration & Energy Strage Smart Grid Pilot Project
Renewable Integration & Energy Strage Smart Grid Pilot ProjectRenewable Integration & Energy Strage Smart Grid Pilot Project
Renewable Integration & Energy Strage Smart Grid Pilot Project
 
Grid Integration of Renewables: Challenges and Solutions
Grid Integration of Renewables: Challenges and SolutionsGrid Integration of Renewables: Challenges and Solutions
Grid Integration of Renewables: Challenges and Solutions
 
Optimal Placement of Distributed Generation on Radial Distribution System for...
Optimal Placement of Distributed Generation on Radial Distribution System for...Optimal Placement of Distributed Generation on Radial Distribution System for...
Optimal Placement of Distributed Generation on Radial Distribution System for...
 
A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...
A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...
A NOVEL CONTROL STRATEGY FOR POWER QUALITY IMPROVEMENT USING ANN TECHNIQUE FO...
 
Grid integration of renewable energy-Priyabrata Patnaik
Grid integration of renewable energy-Priyabrata PatnaikGrid integration of renewable energy-Priyabrata Patnaik
Grid integration of renewable energy-Priyabrata Patnaik
 
Integration of Renewable Energy In Grid
Integration of Renewable Energy In GridIntegration of Renewable Energy In Grid
Integration of Renewable Energy In Grid
 
A grid connected dual voltage source inverter with power quality improvement ...
A grid connected dual voltage source inverter with power quality improvement ...A grid connected dual voltage source inverter with power quality improvement ...
A grid connected dual voltage source inverter with power quality improvement ...
 
OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...
OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...
OPTIMAL PLACEMENT AND SIZING OF CAPACITOR BANKS BASED ON VOLTAGE PROFILE AND ...
 
Renewable energy and grid integration energy transition
Renewable energy and grid integration   energy transitionRenewable energy and grid integration   energy transition
Renewable energy and grid integration energy transition
 
Distributed generation placement
Distributed generation placementDistributed generation placement
Distributed generation placement
 
www.ijerd.com
www.ijerd.comwww.ijerd.com
www.ijerd.com
 
Optimal placement of distributed power flow controller for loss reduction usi...
Optimal placement of distributed power flow controller for loss reduction usi...Optimal placement of distributed power flow controller for loss reduction usi...
Optimal placement of distributed power flow controller for loss reduction usi...
 
Droop control method for parallel dc converters used in standalone pv wind po...
Droop control method for parallel dc converters used in standalone pv wind po...Droop control method for parallel dc converters used in standalone pv wind po...
Droop control method for parallel dc converters used in standalone pv wind po...
 
What is Distributed Generation
What is Distributed GenerationWhat is Distributed Generation
What is Distributed Generation
 
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...
Analysis and Implementation of Power Quality Enhancement Techniques Using Cus...
 
Final talk trident-05-10-2021- dr p k rout-converted
Final talk trident-05-10-2021- dr p k rout-convertedFinal talk trident-05-10-2021- dr p k rout-converted
Final talk trident-05-10-2021- dr p k rout-converted
 

Viewers also liked

Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...Pradeep Avanigadda
 
a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...
a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...
a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...Srirangam Vamshikrishna
 
Managing competence with IT
Managing competence with ITManaging competence with IT
Managing competence with ITKristinaSWo
 
Fmea sod ranking (1)
Fmea sod ranking (1)Fmea sod ranking (1)
Fmea sod ranking (1)Pardeep Yadav
 
Ethics, Do's & Don’ts, Rumors, Twitter
Ethics, Do's & Don’ts, Rumors, TwitterEthics, Do's & Don’ts, Rumors, Twitter
Ethics, Do's & Don’ts, Rumors, Twittermaureenalley
 
Proyectos Inmobiliarios octubre
Proyectos Inmobiliarios octubreProyectos Inmobiliarios octubre
Proyectos Inmobiliarios octubreEl Universal
 
Geological evolution
Geological evolutionGeological evolution
Geological evolutionssealey
 
GUÍA DE COMPRAS Marzo
GUÍA DE COMPRAS MarzoGUÍA DE COMPRAS Marzo
GUÍA DE COMPRAS MarzoEl Universal
 
Geo evol parrish
Geo evol parrishGeo evol parrish
Geo evol parrishssealey
 
How rocksform
How rocksformHow rocksform
How rocksformssealey
 
1st Web Cross Channel Seminar - Udfordringen Online/Offline
1st Web Cross Channel Seminar - Udfordringen Online/Offline1st Web Cross Channel Seminar - Udfordringen Online/Offline
1st Web Cross Channel Seminar - Udfordringen Online/Offline1st Web
 
TÔNG ĐỒ KHUYẾT TẬT
TÔNG ĐỒ KHUYẾT TẬTTÔNG ĐỒ KHUYẾT TẬT
TÔNG ĐỒ KHUYẾT TẬTtongdokhuyettat
 
Opscora Introduction
Opscora IntroductionOpscora Introduction
Opscora IntroductionOpscora
 
Salesforce training with placement
Salesforce training with placementSalesforce training with placement
Salesforce training with placementFTworks
 
The rockcycle
The rockcycleThe rockcycle
The rockcyclessealey
 
Digital collaboration with machine-readable sign language text in the SignWri...
Digital collaboration with machine-readable sign language text in the SignWri...Digital collaboration with machine-readable sign language text in the SignWri...
Digital collaboration with machine-readable sign language text in the SignWri...Stephen Slevinski
 

Viewers also liked (19)

Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...
Grid Interconnection of Renewable Energy Sources at the Distribution Level Wi...
 
a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...
a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...
a new pv/fuel cell based bi-directional pwm converter for micro grid applicat...
 
Mi proyecto de vida point
Mi proyecto de vida pointMi proyecto de vida point
Mi proyecto de vida point
 
Managing competence with IT
Managing competence with ITManaging competence with IT
Managing competence with IT
 
Fmea sod ranking (1)
Fmea sod ranking (1)Fmea sod ranking (1)
Fmea sod ranking (1)
 
Ethics, Do's & Don’ts, Rumors, Twitter
Ethics, Do's & Don’ts, Rumors, TwitterEthics, Do's & Don’ts, Rumors, Twitter
Ethics, Do's & Don’ts, Rumors, Twitter
 
Proyectos Inmobiliarios octubre
Proyectos Inmobiliarios octubreProyectos Inmobiliarios octubre
Proyectos Inmobiliarios octubre
 
Geological evolution
Geological evolutionGeological evolution
Geological evolution
 
GUÍA DE COMPRAS Marzo
GUÍA DE COMPRAS MarzoGUÍA DE COMPRAS Marzo
GUÍA DE COMPRAS Marzo
 
Final draft
Final draftFinal draft
Final draft
 
Geo evol parrish
Geo evol parrishGeo evol parrish
Geo evol parrish
 
How rocksform
How rocksformHow rocksform
How rocksform
 
1st Web Cross Channel Seminar - Udfordringen Online/Offline
1st Web Cross Channel Seminar - Udfordringen Online/Offline1st Web Cross Channel Seminar - Udfordringen Online/Offline
1st Web Cross Channel Seminar - Udfordringen Online/Offline
 
Ekzamen
EkzamenEkzamen
Ekzamen
 
TÔNG ĐỒ KHUYẾT TẬT
TÔNG ĐỒ KHUYẾT TẬTTÔNG ĐỒ KHUYẾT TẬT
TÔNG ĐỒ KHUYẾT TẬT
 
Opscora Introduction
Opscora IntroductionOpscora Introduction
Opscora Introduction
 
Salesforce training with placement
Salesforce training with placementSalesforce training with placement
Salesforce training with placement
 
The rockcycle
The rockcycleThe rockcycle
The rockcycle
 
Digital collaboration with machine-readable sign language text in the SignWri...
Digital collaboration with machine-readable sign language text in the SignWri...Digital collaboration with machine-readable sign language text in the SignWri...
Digital collaboration with machine-readable sign language text in the SignWri...
 

Similar to Grid-Connected Inverters Provide Power and Power Quality

A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...
A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...
A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...IJMER
 
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...IJERA Editor
 
E021203026035
E021203026035E021203026035
E021203026035theijes
 
Power Quality Improvement at Distribution Level for Grid Connected Renewable ...
Power Quality Improvement at Distribution Level for Grid Connected Renewable ...Power Quality Improvement at Distribution Level for Grid Connected Renewable ...
Power Quality Improvement at Distribution Level for Grid Connected Renewable ...IJERA Editor
 
A CONTROL APPROACH FOR GRID INTERFACING INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...
A CONTROL APPROACH FOR GRID INTERFACING  INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...A CONTROL APPROACH FOR GRID INTERFACING  INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...
A CONTROL APPROACH FOR GRID INTERFACING INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...IJMER
 
IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...
IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...
IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...IRJET Journal
 
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...Power Quality Improvement of Grid Interconnection of renewable Energy Based D...
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...IJERA Editor
 
A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...
A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...
A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...IJERA Editor
 
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and ScienceResearch Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Scienceresearchinventy
 
Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...
Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...
Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...IOSR Journals
 
Iaetsd power-quality improvement of grid interconnected
Iaetsd power-quality improvement of grid interconnectedIaetsd power-quality improvement of grid interconnected
Iaetsd power-quality improvement of grid interconnectedIaetsd Iaetsd
 
4.power quality improvement in dg system using shunt active filter
4.power quality improvement in dg system using shunt active filter4.power quality improvement in dg system using shunt active filter
4.power quality improvement in dg system using shunt active filterEditorJST
 
International Journal of Engineering Research and Development (IJERD)
International Journal of Engineering Research and Development (IJERD)International Journal of Engineering Research and Development (IJERD)
International Journal of Engineering Research and Development (IJERD)IJERD Editor
 
Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...
Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...
Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...IJMTST Journal
 

Similar to Grid-Connected Inverters Provide Power and Power Quality (20)

A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...
A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...
A Novel Technique for Enhancing Active and Reactive Power Quality for Renewab...
 
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...
Enhancement in Power Quality With Grid Interconnection of Renewable Energy So...
 
Dw33741745
Dw33741745Dw33741745
Dw33741745
 
Dw33741745
Dw33741745Dw33741745
Dw33741745
 
E021203026035
E021203026035E021203026035
E021203026035
 
Power Quality Improvement at Distribution Level for Grid Connected Renewable ...
Power Quality Improvement at Distribution Level for Grid Connected Renewable ...Power Quality Improvement at Distribution Level for Grid Connected Renewable ...
Power Quality Improvement at Distribution Level for Grid Connected Renewable ...
 
Pc3426502658
Pc3426502658Pc3426502658
Pc3426502658
 
A CONTROL APPROACH FOR GRID INTERFACING INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...
A CONTROL APPROACH FOR GRID INTERFACING  INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...A CONTROL APPROACH FOR GRID INTERFACING  INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...
A CONTROL APPROACH FOR GRID INTERFACING INVERTER IN 3 PHASE 4 WIRE DISTRIBUT...
 
IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...
IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...
IRJET - The Power Quality Improvement with Harmonic Reduction and Stabilizing...
 
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...Power Quality Improvement of Grid Interconnection of renewable Energy Based D...
Power Quality Improvement of Grid Interconnection of renewable Energy Based D...
 
A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...
A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...
A Novel control of a Grid-Interfacing Inverter to Improve the Quality of Powe...
 
Research Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and ScienceResearch Inventy : International Journal of Engineering and Science
Research Inventy : International Journal of Engineering and Science
 
Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...
Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...
Power Flow Control in Grid-Connected Wind Energy Conversion System Using PMSG...
 
I010125361
I010125361I010125361
I010125361
 
Iaetsd power-quality improvement of grid interconnected
Iaetsd power-quality improvement of grid interconnectedIaetsd power-quality improvement of grid interconnected
Iaetsd power-quality improvement of grid interconnected
 
4.power quality improvement in dg system using shunt active filter
4.power quality improvement in dg system using shunt active filter4.power quality improvement in dg system using shunt active filter
4.power quality improvement in dg system using shunt active filter
 
International Journal of Engineering Research and Development (IJERD)
International Journal of Engineering Research and Development (IJERD)International Journal of Engineering Research and Development (IJERD)
International Journal of Engineering Research and Development (IJERD)
 
Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...
Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...
Stability Improvement in Grid Connected Multi Area System using ANFIS Based S...
 
Optimization The Performance of a Synchronization Controller For a 3-Phase Ph...
Optimization The Performance of a Synchronization Controller For a 3-Phase Ph...Optimization The Performance of a Synchronization Controller For a 3-Phase Ph...
Optimization The Performance of a Synchronization Controller For a 3-Phase Ph...
 
Stability analysis of photovoltaic system under grid faults
Stability analysis of photovoltaic system under grid faultsStability analysis of photovoltaic system under grid faults
Stability analysis of photovoltaic system under grid faults
 

More from Pradeep Avanigadda

Transformer protection & maintenance
Transformer protection & maintenanceTransformer protection & maintenance
Transformer protection & maintenancePradeep Avanigadda
 
Operational description of 400kv switchyard NTPC Ramagundam RSTPS
Operational description of 400kv switchyard NTPC Ramagundam RSTPSOperational description of 400kv switchyard NTPC Ramagundam RSTPS
Operational description of 400kv switchyard NTPC Ramagundam RSTPSPradeep Avanigadda
 
SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...
SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...
SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...Pradeep Avanigadda
 
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...Pradeep Avanigadda
 
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...Supercapacitors and Battery power management for Hybrid Vehicle Applications ...
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...Pradeep Avanigadda
 
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCY
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCYDETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCY
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCYPradeep Avanigadda
 
Super capacitors and Battery power management for Hybrid Vehicle Applications...
Super capacitors and Battery power management for Hybrid VehicleApplications...Super capacitors and Battery power management for Hybrid VehicleApplications...
Super capacitors and Battery power management for Hybrid Vehicle Applications...Pradeep Avanigadda
 
Power generation through foot steps
Power generation through foot stepsPower generation through foot steps
Power generation through foot stepsPradeep Avanigadda
 
Hybrid wind solar energy system : a new rectifier stage topology
Hybrid wind solar energy system : a new rectifier stage topologyHybrid wind solar energy system : a new rectifier stage topology
Hybrid wind solar energy system : a new rectifier stage topologyPradeep Avanigadda
 
Simulation of ac dc step up converter for low efficient energy harvesting
Simulation of ac dc step up converter for low efficient energy harvestingSimulation of ac dc step up converter for low efficient energy harvesting
Simulation of ac dc step up converter for low efficient energy harvestingPradeep Avanigadda
 

More from Pradeep Avanigadda (13)

Transformer protection & maintenance
Transformer protection & maintenanceTransformer protection & maintenance
Transformer protection & maintenance
 
INFRARED PLASTIC SOLAR CELLS
INFRARED PLASTIC SOLAR CELLSINFRARED PLASTIC SOLAR CELLS
INFRARED PLASTIC SOLAR CELLS
 
Operational description of 400kv switchyard NTPC Ramagundam RSTPS
Operational description of 400kv switchyard NTPC Ramagundam RSTPSOperational description of 400kv switchyard NTPC Ramagundam RSTPS
Operational description of 400kv switchyard NTPC Ramagundam RSTPS
 
SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...
SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...
SUPERCAPACITORS AND BATTERY POWER MANAGEMENT FOR HYBRID VEHICLE APPLICATIONS ...
 
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUE...
 
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...Supercapacitors and Battery power management for Hybrid Vehicle Applications ...
Supercapacitors and Battery power management for Hybrid Vehicle Applications ...
 
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCY
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCYDETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCY
DETECTING POWER GRID SYNCHRONISATION FAILURE ON SENSING BAD VOLTAGE OR FREQUENCY
 
Super capacitors and Battery power management for Hybrid Vehicle Applications...
Super capacitors and Battery power management for Hybrid VehicleApplications...Super capacitors and Battery power management for Hybrid VehicleApplications...
Super capacitors and Battery power management for Hybrid Vehicle Applications...
 
Water PPT
Water PPTWater PPT
Water PPT
 
Concentrated solar power
Concentrated solar powerConcentrated solar power
Concentrated solar power
 
Power generation through foot steps
Power generation through foot stepsPower generation through foot steps
Power generation through foot steps
 
Hybrid wind solar energy system : a new rectifier stage topology
Hybrid wind solar energy system : a new rectifier stage topologyHybrid wind solar energy system : a new rectifier stage topology
Hybrid wind solar energy system : a new rectifier stage topology
 
Simulation of ac dc step up converter for low efficient energy harvesting
Simulation of ac dc step up converter for low efficient energy harvestingSimulation of ac dc step up converter for low efficient energy harvesting
Simulation of ac dc step up converter for low efficient energy harvesting
 

Recently uploaded

ClimART Action | eTwinning Project
ClimART Action    |    eTwinning ProjectClimART Action    |    eTwinning Project
ClimART Action | eTwinning Projectjordimapav
 
Keynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-designKeynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-designMIPLM
 
Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)Mark Reed
 
Using Grammatical Signals Suitable to Patterns of Idea Development
Using Grammatical Signals Suitable to Patterns of Idea DevelopmentUsing Grammatical Signals Suitable to Patterns of Idea Development
Using Grammatical Signals Suitable to Patterns of Idea Developmentchesterberbo7
 
week 1 cookery 8 fourth - quarter .pptx
week 1 cookery 8  fourth  -  quarter .pptxweek 1 cookery 8  fourth  -  quarter .pptx
week 1 cookery 8 fourth - quarter .pptxJonalynLegaspi2
 
4.16.24 Poverty and Precarity--Desmond.pptx
4.16.24 Poverty and Precarity--Desmond.pptx4.16.24 Poverty and Precarity--Desmond.pptx
4.16.24 Poverty and Precarity--Desmond.pptxmary850239
 
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptxINTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptxHumphrey A Beña
 
CONCEPT OF MUTATION AND ITS CLASSIFICATION .pptx
CONCEPT OF MUTATION AND ITS CLASSIFICATION .pptxCONCEPT OF MUTATION AND ITS CLASSIFICATION .pptx
CONCEPT OF MUTATION AND ITS CLASSIFICATION .pptxAnupkumar Sharma
 
Choosing the Right CBSE School A Comprehensive Guide for Parents
Choosing the Right CBSE School A Comprehensive Guide for ParentsChoosing the Right CBSE School A Comprehensive Guide for Parents
Choosing the Right CBSE School A Comprehensive Guide for Parentsnavabharathschool99
 
PRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptx
PRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptxPRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptx
PRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptxAnupkumar Sharma
 
Congestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationCongestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationdeepaannamalai16
 
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdfInclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdfTechSoup
 
How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17Celine George
 
4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptx4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptxmary850239
 
Active Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdfActive Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdfPatidar M
 
DIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptx
DIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptxDIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptx
DIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptxMichelleTuguinay1
 
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptxMULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptxAnupkumar Sharma
 
Grade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdf
Grade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdfGrade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdf
Grade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdfJemuel Francisco
 

Recently uploaded (20)

ClimART Action | eTwinning Project
ClimART Action    |    eTwinning ProjectClimART Action    |    eTwinning Project
ClimART Action | eTwinning Project
 
Keynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-designKeynote by Prof. Wurzer at Nordex about IP-design
Keynote by Prof. Wurzer at Nordex about IP-design
 
Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)Influencing policy (training slides from Fast Track Impact)
Influencing policy (training slides from Fast Track Impact)
 
Using Grammatical Signals Suitable to Patterns of Idea Development
Using Grammatical Signals Suitable to Patterns of Idea DevelopmentUsing Grammatical Signals Suitable to Patterns of Idea Development
Using Grammatical Signals Suitable to Patterns of Idea Development
 
week 1 cookery 8 fourth - quarter .pptx
week 1 cookery 8  fourth  -  quarter .pptxweek 1 cookery 8  fourth  -  quarter .pptx
week 1 cookery 8 fourth - quarter .pptx
 
4.16.24 Poverty and Precarity--Desmond.pptx
4.16.24 Poverty and Precarity--Desmond.pptx4.16.24 Poverty and Precarity--Desmond.pptx
4.16.24 Poverty and Precarity--Desmond.pptx
 
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptxINTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
INTRODUCTION TO CATHOLIC CHRISTOLOGY.pptx
 
CONCEPT OF MUTATION AND ITS CLASSIFICATION .pptx
CONCEPT OF MUTATION AND ITS CLASSIFICATION .pptxCONCEPT OF MUTATION AND ITS CLASSIFICATION .pptx
CONCEPT OF MUTATION AND ITS CLASSIFICATION .pptx
 
Choosing the Right CBSE School A Comprehensive Guide for Parents
Choosing the Right CBSE School A Comprehensive Guide for ParentsChoosing the Right CBSE School A Comprehensive Guide for Parents
Choosing the Right CBSE School A Comprehensive Guide for Parents
 
PRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptx
PRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptxPRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptx
PRINCIPLE & APPLICATIONS OF IMMUNO BLOTTING TECHNIQUES.pptx
 
LEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptx
LEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptxLEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptx
LEFT_ON_C'N_ PRELIMS_EL_DORADO_2024.pptx
 
Congestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationCongestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentation
 
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdfInclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
Inclusivity Essentials_ Creating Accessible Websites for Nonprofits .pdf
 
How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17How to Add Barcode on PDF Report in Odoo 17
How to Add Barcode on PDF Report in Odoo 17
 
4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptx4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptx
 
YOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptx
YOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptxYOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptx
YOUVE_GOT_EMAIL_PRELIMS_EL_DORADO_2024.pptx
 
Active Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdfActive Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdf
 
DIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptx
DIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptxDIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptx
DIFFERENT BASKETRY IN THE PHILIPPINES PPT.pptx
 
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptxMULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
 
Grade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdf
Grade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdfGrade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdf
Grade 9 Quarter 4 Dll Grade 9 Quarter 4 DLL.pdf
 

Grid-Connected Inverters Provide Power and Power Quality

  • 1. IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011 307 Grid Interconnection of Renewable Energy Sources at the Distribution Level With Power-Quality Improvement Features Mukhtiar Singh, Student Member, IEEE, Vinod Khadkikar, Member, IEEE, Ambrish Chandra, Senior Member, IEEE, and Rajiv K. Varma, Senior Member, IEEE Abstract—Renewable energy resources (RES) are being increas- ingly connected in distribution systems utilizing power electronic converters. This paper presents a novel control strategy for achieving maximum benefits from these grid-interfacing inverters when installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorpo- rating active power filter functionality. The inverter can thus be utilized as: 1) power converter to inject power generated from RES to the grid, and 2) shunt APF to compensate current unbal- ance, load current harmonics, load reactive power demand and load neutral current. All of these functions may be accomplished either individually or simultaneously. With such a control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at point of common coupling appears as balanced linear load to the grid. This new control concept is demonstrated with extensive MATLAB/Simulink simu- lation studies and validated through digital signal processor-based laboratory experimental results. Index Terms—Active power filter (APF), distributed generation (DG), distribution system, grid interconnection, power quality (PQ), renewable energy. I. INTRODUCTION ELECTRIC utilities and end users of electric power are becoming increasingly concerned about meeting the growing energy demand. Seventy five percent of total global energy demand is supplied by the burning of fossil fuels. But increasing air pollution, global warming concerns, diminishing fossil fuels and their increasing cost have made it necessary to look towards renewable sources as a future energy solution. Since the past decade, there has been an enormous interest in many countries on renewable energy for power generation. The market liberalization and government’s incentives have further accelerated the renewable energy sector growth. Manuscript received March 15, 2009; revised July 04, 2010; accepted August 19, 2010. Date of publication November 01, 2010; date of current version De- cember 27, 2010. Paper no. TPWRD-00216-2009. M. Singh and A. Chandra are with the Department of Electrical Engineering, Ecole de technologie superieure, Montreal, QC H3C 1K3, Canada (e-mail: smukhtiar_79@yahoo.co.in; ambrish.chandra@etsmtl.ca). V. Khadkikar is with the Electrical Power Engineering Program, Masdar In- stitute, Abu Dhabi, United Arab Emirates (e-mail: vkhadkikar@masdar.ac.ae). R. K. Varma is with the Department of Electrical and Computer Engineering, University of Western Ontario, London, ON N6A 5B8, Canada (e-mail: rkvarma@uwo.ca). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TPWRD.2010.2081384 Renewable energy source (RES) integrated at distribution level is termed as distributed generation (DG). The utility is concerned due to the high penetration level of intermittent RES in distribution systems as it may pose a threat to network in terms of stability, voltage regulation and power-quality (PQ) issues. Therefore, the DG systems are required to comply with strict technical and regulatory frameworks to ensure safe, reliable and efficient operation of overall network. With the ad- vancement in power electronics and digital control technology, the DG systems can now be actively controlled to enhance the system operation with improved PQ at PCC. However, the extensive use of power electronics based equipment and non-linear loads at PCC generate harmonic currents, which may deteriorate the quality of power [1], [2]. Generally, current controlled voltage source inverters are used to interface the intermittent RES in distributed system. Recently, a few control strategies for grid connected inverters incorporating PQ solution have been proposed. In [3] an inverter operates as active inductor at a certain frequency to absorb the harmonic current. But the exact calculation of network inductance in real-time is difficult and may deteriorate the con- trol performance. A similar approach in which a shunt active filter acts as active conductance to damp out the harmonics in distribution network is proposed in [4]. In [5], a control strategy for renewable interfacing inverter based on - theory is proposed. In this strategy both load and inverter current sensing is required to compensate the load current harmonics. The non-linear load current harmonics may result in voltage harmonics and can create a serious PQ problem in the power system network. Active power filters (APF) are extensively used to compensate the load current harmonics and load unbalance at distribution level. This results in an additional hardware cost. However, in this paper authors have incorporated the features of APF in the, conventional inverter interfacing renewable with the grid, without any additional hardware cost. Here, the main idea is the maximum utilization of inverter rating which is most of the time underutilized due to intermittent nature of RES. It is shown in this paper that the grid-interfacing inverter can effectively be utilized to perform following important functions: 1) transfer of active power harvested from the renewable resources (wind, solar, etc.); 2) load reactive power demand support; 3) current harmonics compensation at PCC; and 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. The PQ constraints at the PCC can therefore be strictly maintained within the utility standards without addi- tional hardware cost. 0885-8977/$26.00 © 2010 IEEE
  • 2. 308 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011 Fig. 1. Schematic of proposed renewable based distributed generation system. The paper is arranged as follows: Section II describes the system under consideration and the controller for grid-in- terfacing inverter. A digital simulation study is presented in Section III. Extensive experimental results are discussed in Section IV and, finally, Section V concludes the paper. II. SYSTEM DESCRIPTION The proposed system consists of RES connected to the dc-link of a grid-interfacing inverter as shown in Fig. 1. The voltage source inverter is a key element of a DG system as it interfaces the renewable energy source to the grid and delivers the generated power. The RES may be a DC source or an AC source with rectifier coupled to dc-link. Usually, the fuel cell and photovoltaic energy sources generate power at variable low dc voltage, while the variable speed wind turbines generate power at variable ac voltage. Thus, the power generated from these renewable sources needs power conditioning (i.e., dc/dc or ac/dc) before connecting on dc-link [6]–[8]. The dc-capac- itor decouples the RES from grid and also allows independent control of converters on either side of dc-link. A. DC-Link Voltage and Power Control Operation Due to the intermittent nature of RES, the generated power is of variable nature. The dc-link plays an important role in trans- ferring this variable power from renewable energy source to the grid. RES are represented as current sources connected to the dc-link of a grid-interfacing inverter. Fig. 2 shows the system- atic representation of power transfer from the renewable energy resources to the grid via the dc-link. The current injected by re- newable into dc-link at voltage level can be given as (1) where is the power generated from RES. Fig. 2. DC-Link equivalent diagram. The current flow on the other side of dc-link can be repre- sented as, (2) where and are total power available at grid-in- terfacing inverter side, active power supplied to the grid and in- verter losses, respectively. If inverter losses are negligible then . B. Control of Grid Interfacing Inverter The control diagram of grid- interfacing inverter for a 3-phase 4-wire system is shown in Fig. 3. The fourth leg of inverter is used to compensate the neutral current of load. The main aim of proposed approach is to regulate the power at PCC during: 1) ; 2) ; and 3) . While performing the power management oper- ation, the inverter is actively controlled in such a way that it always draws/ supplies fundamental active power from/ to the grid. If the load connected to the PCC is non-linear or unbal- anced or the combination of both, the given control approach also compensates the harmonics, unbalance, and neutral current. The duty ratio of inverter switches are varied in a power cycle such that the combination of load and inverter injected power
  • 3. SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 309 Fig. 3. Block diagram representation of grid-interfacing inverter control. appears as balanced resistive load to the grid. The regulation of dc-link voltage carries the information regarding the exchange of active power in between renewable source and grid. Thus the output of dc-link voltage regulator results in an active current . The multiplication of active current component with unity grid voltage vector templates ( , and ) generates the reference grid currents ( , and ). The reference grid neutral current is set to zero, being the instantaneous sum of balanced grid currents. The grid synchronizing angle ob- tained from phase locked loop (PLL) is used to generate unity vector template as [9]–[11] (3) (4) (5) The actual dc-link voltage is sensed and passed through a first-order low pass filter (LPF) to eliminate the presence of switching ripples on the dc-link voltage and in the generated reference current signals. The difference of this filtered dc-link voltage and reference dc-link voltage is given to a dis- crete-PI regulator to maintain a constant dc-link voltage under varying generation and load conditions. The dc-link voltage error at th sampling instant is given as: (6) The output of discrete-PI regulator at th sampling instant is expressed as (7) where and are proportional and integral gains of dc-voltage regulator. The instantaneous values of reference three phase grid currents are computed as (8) (9) (10) The neutral current, present if any, due to the loads connected to the neutral conductor should be compensated by forth leg of grid-interfacing inverter and thus should not be drawn from the grid. In other words, the reference current for the grid neutral current is considered as zero and can be expressed as (11) The reference grid currents ( and ) are compared with actual grid currents ( and ) to compute the cur- rent errors as (12) (13) (14) (15) These current errors are given to hysteresis current controller. The hysteresis controller then generates the switching pulses ( to ) for the gate drives of grid-interfacing inverter. The average model of 4-leg inverter can be obtained by the following state space equations (16) (17)
  • 4. 310 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011 (18) (19) (20) where , and are the three-phase ac switching voltages generated on the output terminal of inverter. These inverter output voltages can be modeled in terms of in- stantaneous dc bus voltage and switching pulses of the inverter as (21) (22) (23) (24) Similarly the charging currents , and on dc bus due to the each leg of inverter can be expressed as (25) (26) (27) (28) The switching pattern of each IGBT inside inverter can be for- mulated on the basis of error between actual and reference cur- rent of inverter, which can be explained as: If , then upper switch will be OFF and lower switch will be ON in the phase “a” leg of inverter. If , then upper switch will be ON and lower switch will be OFF in the phase “a” leg of inverter. where is the width of hysteresis band. On the same principle, the switching pulses for the other remaining three legs can be derived. III. SIMULATION RESULTS In order to verify the proposed control approach to achieve multi-objectives for grid interfaced DG systems connected to a 3-phase 4-wire network, an extensive simulation study is carried out using MATLAB/Simulink. A 4-leg current controlled voltage source inverter is actively controlled to achieve balanced sinusoidal grid currents at unity power factor (UPF) despite of highly unbalanced nonlinear load at PCC under varying renewable generating conditions. A RES with variable output power is connected on the dc-link of grid-in- terfacing inverter. An unbalanced 3-phase 4-wire nonlinear load, whose unbalance, harmonics, and reactive power need to be compensated, is connected on PCC. The waveforms of Fig. 4. Simulation results: (a) Grid voltages, (b) Grid Currents (c) Unbalanced load currents, (d) Inverter Currents. grid voltage , grid currents ( ), un- balanced load current and inverter currents are shown in Fig. 4. The corre- sponding active-reactive powers of grid , load and inverter are shown in Fig. 5. Positive values of grid active-reactive powers and inverter active-reactive powers imply that these powers flow from grid side towards PCC and from inverter towards PCC, respectively. The active and reactive powers absorbed by the load are denoted by positive signs. Initially, the grid-interfacing inverter is not connected to the network (i.e., the load power demand is totally supplied by the grid alone). Therefore, before time s, the grid cur- rent profile in Fig. 4(b) is identical to the load current profile of Fig. 4(c). At s, the grid-interfacing inverter is con- nected to the network. At this instant the inverter starts injecting the current in such a way that the profile of grid current starts changing from unbalanced non linear to balanced sinusoidal current as shown in Fig. 4(b). As the inverter also supplies the
  • 5. SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 311 Fig. 5. Simulation results: (a) PQ-Grid, (b) PQ-Load, (c) PQ-Inverter, (d) dc-link voltage. load neutral current demand, the grid neutral current be- comes zero after s. At s, the inverter starts injecting active power gen- erated from RES . Since the generated power is more than the load power demand the additional power is fed back to the grid. The negative sign of , after time 0.72 s suggests that the grid is now receiving power from RES. More- over, the grid-interfacing inverter also supplies the load reactive power demand locally. Thus, once the inverter is in operation the grid only supplies/receives fundamental active power. At s, the active power from RES is increased to evaluate the performance of system under variable power gener- ation from RES. This results in increased magnitude of inverter current. As the load power demand is considered as constant, this additional power generated from RES flows towards grid, which can be noticed from the increased magnitude of grid cur- rent as indicated by its profile. At s, the power available from RES is reduced. The corresponding change in the inverter and grid currents can be seen from Fig. 4. The active and re- active power flows between the inverter, load and grid during increase and decrease of energy generation from RES can be noticed from Fig. 5. The dc-link voltage across the grid- inter- facing inverter (Fig. 5(d)) during different operating condition is maintained at constant level in order to facilitate the active and reactive power flow. Thus from the simulation results, it is evi- dent that the grid-interfacing inverter can be effectively used to compensate the load reactive power, current unbalance and cur- rent harmonics in addition to active power injection from RES. This enables the grid to supply/ receive sinusoidal and balanced power at UPF. IV. EXPERIMENTAL VALIDATION The performance of the proposed control approach is vali- dated with the help of a scaled laboratory prototype that has system parameters as given in Table I. The RES is emulated TABLE I SYSTEM PARAMETER using an auxiliary controlled converter, which injects varying active power at the dc-link of an insulated gate bipolar transistor (IGBT) based 4-leg voltage source inverter connected to grid. A 3-phase 4-wire nonlinear load, composed of 3-phase non-linear balanced load, 1-phase R-L load between phase and neutral and 1-phase non-linear load between phase and neutral, is con- nected to the grid. The total harmonics distortions (THDs) of phase and load currents are noticed as 14.21%, 22.93%, and 16.21%, respectively. The DS1104® DSP of dSPACE is uti- lized to generate the reference grid current signals in real-time. The difference of reference and actual grid current signals is applied to external hysteresis board to generate the gate pulses for IGBT’s. The proposed control approach requires a sam- pling time of 75 s to execute the MATLAB/Simulink gener- ated C-codes in real-time. The experimental results are divided into three different modes of operation in order to highlight the validity of pro- posed controller. First mode of operation considers a situation when there is no power generation from RES. Under such condition, the grid-interfacing inverter is utilized as shunt APF to enhance the quality of power at PCC. While in second mode of operation, the inverter injects RES active power into grid and also incorporates the active power filtering functionality. In the third mode, the dynamic operation of proposed controller is examined. The experimental results are given in Figs. 6–10. All the voltage and current waveforms are captured utilizing an oscilloscope, whereas, the active and reactive powers are cap- tured in real-time using ControlDesk Developer environment. A. Mode of Operation—PQ Enhancement Fig. 6 shows the experimental results for active power fil- tering mode of operation when there is no power generation from RES. All the current waveforms are shown with respec- tive to grid side phase voltage . Fig. 6(a) shows the profile of the unbalance non-linear load currents. The grid current pro- file, when grid-interfacing inverter controlled as shunt APF, is shown in Fig. 6(b). It can be noticed that the highly unbalanced load currents, after compensation, appear as pure sinusoidal bal- anced set of currents on grid side. The grid current THD’s are reduced to 2.36%, 1.68%, 3.65% for and phases, respec- tively. In Fig. 6(c), the compensating inverter currents are shown for each phase along with dc-link voltage. For the experimental study, the dc-link voltage is maintained at 100 V. Fig. 6(d) shows the traces for neutral current of grid, load and inverter. The load neutral current due to single-phase loads is effectively compen- sated by the 4th leg of inverter such that the current in grid side neutral conductor is reduced to zero.
  • 6. 312 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011 Fig. 6. Experimental results for the active power filtering mode (P = 0): (a) unbalanced load currents, (b) grid currents after compensation, (c) currents injected by grid-interfacing inverter, (d) load, grid and inverter neutral currents. Fig. 7. Experimental results for the active power filtering mode (P = 0): active and reactive power flow in real-time.
  • 7. SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 313 Fig. 8. Experimental results for the active power filtering and renewable power injection mode (P > P ): (a) phase aperformance, (b) phase bperformance, (c) phase c performance, (d) grid currents (e) load, grid and inverter neutral currents. Fig. 7 shows the total active and reactive powers of grid, load and inverter. In the APF mode of operation, the inverter con- sumes a small amount of active power to maintain the dc-link voltage and to overcome the losses associated with inverter, while most of the load reactive power need is supported by in- verter effectively. Thus, this mode of operation validates the concept of utilization of grid-interfacing inverter as shunt APF when there is no power generation from the RES. The experi- mental results demonstrate the effective compensations of load current unbalance, harmonics and reactive power. B. Mode of Operation—Simultaneous PQ Enhancement and RES Power Injection The experimental results for simultaneous active power fil- tering and RES power injection mode are shown in Fig. 8. In this case study it is considered that the generated power at grid-in- terfacing inverter is more than the total load power demand. Therefore, after meeting the load power demand, the additional RES power flows towards grid. The profiles of grid, load and inverter currents for individual phases are shown in Figs. 8(a), (b) & (c) for phase and , respectively. As noticed from Fig. 8(a) to (c), the inverter currents consist of two compo- nents: 1) steady-state load current component and 2) grid active power injection component. Thus the grid-interfacing inverter now provides the entire load power demand (active, reactive and harmonics) locally and feeds the additional active power (sinusoidal and balanced) to the grid. The exact out-of phase relationship between phase— grid voltage and phase— grid current suggests that this additional power is fed to the grid at UPF. The three-phase grid currents (Fig. 8(d)) suggest that the injected active power from RES to the grid is supplied as bal- anced active power even the load on the system is unbalanced in nature. During both mode of operation, as the load on the system is considered constant, the load neutral current profile and its compensation is identical to the one already discussed in previous subsection and can also be noticed from Figs. 6(d) and 8(e). The exchange of total active and reactive powers between grid, load and inverter are shown in Fig. 9. The negative sign of total grid side active power demonstrates that the excess power generated by RES flows towards grid side. Thus, this case study demonstrates that the grid-interfacing inverter can simultane- ously be utilized to inject power generated from RES to PCC and to improve the quality of power (current unbalance compensa- tion, current harmonics compensation, load reactive power sup- port, neutral current compensation) at PCC.
  • 8. 314 IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 26, NO. 1, JANUARY 2011 Fig. 9. Experimental results for the active power filtering and renewable power injection mode (P > P ): active and reactive power flow in real time. Fig. 10. Experimental results: Dynamic performance of proposed approach. C. Dynamic Performance of Proposed Control Approach Fig. 10 shows the experimental results to validate the dynamic performance of proposed control approach under different modes of operation. Initially, it is considered that the system is working under mode-A operating condition (i.e., non-linear load current harmonics and reactive power com- pensation). After few cycles, the power at dc-link is initially increased and then decreased, which can be noticed from the amplitude of injected inverter current profile. The corre- sponding decrease (for increased power level at dc-link) and increase (for decreased power level at dc-link) in grid current magnitude can also be noticed from Fig. 10, under constant load conditions. Thus, the proposed controller precisely manages any variation in real power at dc-link and effectively feeds it to the main grid. A smooth changeover from mode-A operating condition to the mode-B can be noticed from Fig. 10. V. CONCLUSION This paper has presented a novel control of an existing grid- interfacing inverter to improve the quality of power at PCC for a 3-phase 4-wire DG system. It has been shown that the grid-inter- facing inverter can be effectively utilized for power conditioning without affecting its normal operation of real power transfer. The grid-interfacing inverter with the proposed approach can be utilized to: i) inject real power generated from RES to the grid, and/or, ii) operate as a shunt Active Power Filter (APF). This approach thus eliminates the need for additional power conditioning equipment to improve the quality of power at PCC. Extensive MATLAB/Simulink simulation as well as the DSP based experimental results have validated the proposed approach and have shown that the grid-interfacing inverter can be utilized as a multi-function device. It is further demonstrated that the PQ enhancement can be achieved under three different scenarios: 1) , 2) , and 3) . The current unbalance, current harmonics and load reactive power, due to unbalanced and non-linear load connected to the PCC, are compensated ef- fectively such that the grid side currents are always maintained as balanced and sinusoidal at unity power factor. Moreover, the load neutral current is prevented from flowing into the grid side by compensating it locally from the fourth leg of inverter. When the power generated from RES is more than the total load power demand, the grid-interfacing inverter with the proposed control approach not only fulfills the total load active and reactive power demand (with harmonic compensation) but also delivers the excess generated sinusoidal active power to the grid at unity power factor.
  • 9. SINGH et al.: GRID INTERCONNECTION OF RENEWABLE ENERGY SOURCES 315 REFERENCES [1] J. M. Guerrero, L. G. de Vicuna, J. Matas, M. Castilla, and J. Miret, “A wireless controller to enhance dynamic performance of parallel in- verters in distributed generation systems,” IEEE Trans. Power Elec- tron., vol. 19, no. 5, pp. 1205–1213, Sep. 2004. [2] J. H. R. Enslin and P. J. M. Heskes, “Harmonic interaction between a large number of distributed power inverters and the distribution net- work,” IEEE Trans. Power Electron., vol. 19, no. 6, pp. 1586–1593, Nov. 2004. [3] U. Borup, F. Blaabjerg, and P. N. Enjeti, “Sharing of nonlinear load in parallel-connected three-phase converters,” IEEE Trans. Ind. Appl., vol. 37, no. 6, pp. 1817–1823, Nov./Dec. 2001. [4] P. Jintakosonwit, H. Fujita, H. Akagi, and S. Ogasawara, “Implemen- tation and performance of cooperative control of shunt active filters for harmonic damping throughout a power distribution system,” IEEE Trans. Ind. Appl., vol. 39, no. 2, pp. 556–564, Mar./Apr. 2003. [5] J. P. Pinto, R. Pregitzer, L. F. C. Monteiro, and J. L. Afonso, “3-phase 4-wire shunt active power filter with renewable energy interface,” pre- sented at the Conf. IEEE Rnewable Energy & Power Quality, Seville, Spain, 2007. [6] F. Blaabjerg, R. Teodorescu, M. Liserre, and A. V. Timbus, “Overview of control and grid synchronization for distributed power generation systems,” IEEE Trans. Ind. Electron., vol. 53, no. 5, pp. 1398–1409, Oct. 2006. [7] J. M. Carrasco, L. G. Franquelo, J. T. Bialasiewicz, E. Galván, R. C. P. Guisado, M. Á. M. Prats, J. I. León, and N. M. Alfonso, “Power- electronic systems for the grid integration of renewable energy sources: A survey,” IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1002–1016, Aug. 2006. [8] B. Renders, K. De Gusseme, W. R. Ryckaert, K. Stockman, L. Van- develde, and M. H. J. Bollen, “Distributed generation for mitigating voltage dips in low-voltage distribution grids,” IEEE Trans. Power. Del., vol. 23, no. 3, pp. 1581–1588, Jul. 2008. [9] V. Khadkikar, A. Chandra, A. O. Barry, and T. D. Nguyen, “Appli- cation of UPQC to protect a sensitive load on a polluted distribution network,” in Proc. Annu. Conf. IEEE Power Eng. Soc. Gen. Meeting, 2006, pp. 867–872. [10] M. Singh and A. Chandra, “Power maximization and voltage sag/swell ride-through capability of PMSG based variable speed wind energy conversion system,” in Proc. IEEE 34th Annu. Conf. Indus. Electron. Soc., 2008, pp. 2206–2211. [11] P. Rodríguez, J. Pou, J. Bergas, J. I. Candela, R. P. Burgos, and D. Boroyevich, “Decoupled double synchronous reference frame PLL for power converters control,” IEEE Trans. Power Electron, vol. 22, no. 2, pp. 584–592, Mar. 2007. Mukhtiar Singh (S’08) received the B.Tech. and M.Tech. degrees in electrical engineering from the National Institute of Technology (formerly known as R.E.C. Kurukshetra), Kurukshetra, India, in 1999 and 2001, respectively, and is currently pursuing the Ph.D. degree at Ecole de Technologie Superieure, Universite du Quebec, Montreal, QC, Canada, under the National Overseas Scholarship, funded by the Government of India. He was a faculty member at B.M.I.E.T., Sonepat, India, and K.I.E.T., Ghaziabad, India, during 2000–2002. Since 2002, he has been an Assistant Professor in the Department of Electrical Engineering, Deenbandhu Chhoturam University of Science and Technology, Sonepat, India. Currently, he is on study leave. His research interests include renewable energy sources, power quality, energy storage systems, electric vehicles, and power electronics and drives. Vinod Khadkikar (S’06–M’09) received the B.E. degree in electrical engineering from the Gov- ernment College of Engineering, Dr. B. A. M. U. University, Aurangabad, India, in 2000, the M.Tech. degree in electrical engineering from the Indian Institute of Technology (I.I.T.), New Delhi, India, in 2002, and the Ph.D. degrees in electrical engineering from the École de Technologie Supérieure (E.T.S.), Montréal, QC, Canada, in 2008. From 2008 to 2010, he was a Postdoctoral Fellow at the University of Western Ontario, London, ON, Canada. Since 2010, he has been an Assistant Professor at Masdar Institute, Abu Dhabi, United Arab Emirates. Currently, he is with the visiting faculty at the Massachusetts Institute of Technology, Cambridge, MA. His research interests include applications of power electronics in distribution systems, power-quality enhancement, active power filters, applications of power electronics in renew- able energy resources, and grid interconnection issues. Ambrish Chandra (SM’99) was born in India in 1955. He received the B.E. degree from the University of Roorkee, India, in 1977, the M.Tech. degree from the Indian Institute of Technology, New Delhi, India, in 1980, and the Ph.D. degree from the University of Calgary, Calgary, AB, Canada, in 1987. He was a Lecturer and then a Reader at the University of Roorkee. Since 1994, he has been a Professor in the Electrical Engineering Department at École de Technologie Supérieure, Universié du Québec, Montréal, Canada. His main research interests are power quality, active filters, static reactive power compensation, flexible ac transmission systems, and power-quality issues related to autonomous and grid–connected renewable energy resources. Dr. Chandra is a member of the Ordre des Ingénieurs du Québec, Canada. Rajiv K. Varma (SM’96) received the B.Tech. and Ph.D. degrees in electrical engineering from the In- dian Institute of Technology (IIT), Kanpur, India, in 1980 and 1988, respectively. Currently, he is an Associate Professor at the University of Western Ontario (UWO), London, ON, Canada. Prior to this position, he was a faculty member in the Electrical Engineering Department at the Indian Institute of Technology, Kanpur, India, from 1989 to 2001. While in India, he was awarded the Government of India BOYSCAST Young Scien- tist Fellowship in 1992–1993 to conduct research on flexible ac transmission systems (FACTS) at the UWO. His research interests include FACTS, power systems stability, and grid integration of wind and photovoltaic solar power systems. Dr. Varma received the Fulbright Grant of the U.S. Educational Foundation in India to conduct research in FACTS at the Bonneville Power Administration, Portland, OR, during 1998. He is the Chair of IEEE Working Group on “FACTS and HVDC Bibliography” and is active on a number of other IEEE working groups. He has received several Teaching Excellence awards at the Faculty of Engineering and University level at UWO.