INTERNATIONAL JOURNAL OF INNOVATION IN ENGINEERING RESEARCH & MANAGEMENT ISSN :2348-4918
Wind system using Static Synchronous Compensator
Technology with improved reactive power
Shilpa Vishwakarma1, Preeti Jain2
Electrical Engineering, Jabalpur Engineering College, Jabalpur (M.P.),
2
Reseach Guide,Department of Electrical Engineering,Jabalpur Engineering College Jabalpur
(M.P.)
------------------------------------------------------------*****------------------------------------------------------Abstract—This paper investigates when integrated Static Synchronous Compensator Technology using Wind
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system with improved reactive power to the power system, large wind farms pose stability and control issues. A
thorough study is needed to identify the potential problems and to develop measures to mitigate them. Although
integration of high levels of wind power into an existing transmission system does not require a major redesign,
it necessitates additional control and compensating equipment to enable recovery from severe system
disturbances. Static Synchronous Compensator (STATCOM) along with wind farms for the purpose of
stabilizing the reactive power and grid voltage after grid-side disturbances such as a three phase short circuit
fault, temporary trip of a wind turbine and sudden load changes. The strategy focuses on a fundamental grid
operational requirement to maintain proper voltages at the point of common coupling by regulating voltage. The
DC voltage at individual wind turbine (WT) inverters is also stabilized to facilitate continuous operation of wind
turbines during disturbances.
Keywords: power quality, wind system, STATCOM, matlab
1 Introduction
The wind power penetration has increased
dramatically in the past few years, hence it has
become necessary to address problems associated
with maintaining a stable electric power system
that contains different sources of energy including
hydro, thermal, coal, nuclear, wind, and solar. In
the past, the total installed wind power capacity
was a small fraction of the power system and
continuous connection of the wind farm to the grid
was not a major concern. With an increasing share
derived from wind power sources, continuous
connection of wind farms to the system has played
an increasing role in enabling uninterrupted power
supply to the load, even in the case of minor
disturbances. The wind farm capacity is being
continuously increased through the installation of
more and larger wind turbines. Voltage stability
and an efficient fault ride through capability are the
basic requirements for higher penetration. Wind
turbines have to be able to continue uninterrupted
operation under transient voltage conditions to be
in accordance with the grid codes [2]. Grid codes
are certain standards set by regulating agencies.
Wind power systems should meet these
requirements for interconnection to the grid.
Different grid code standards are established by
different regulating bodies, but Nordic grid codes
are becoming increasingly popular [3] Flexible AC
Transmission Systems (FACTS) such as the Static
Synchronous Compensator (STATCOM) and the
Unified Power Flow Controller (UPFC) are being
used extensively in power systems because of their
ability to provide flexible power flow control [5].
The main motivation for choosing STATCOM in
wind farms is its ability to provide busbar system
voltage support either by supplying and/or
absorbing reactive power into the system. The
applicability of a STATCOM in wind farms has
been investigated and the results from early studies
indicate that it is able to supply reactive power
requirements of plant are described in [8]. The
requirements, assumptions and structure of an
aggregate model of a wind park with constant
speed turbine and variable speed turbines are
discussed in [9]. This thesis explores the possibility
of enabling wind farms to provide voltage support
during normal conditions, as well as under
conditions when system voltages are not within
desired limits. The transient behaviour of wind
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VOLUME :02 Issue 03 I Paper id-IJIERM-II-III-1201 , June 2015
INTERNATIONAL JOURNAL OF INNOVATION IN ENGINEERING RESEARCH & MANAGEMENT ISSN :2348-4918
farms can be improved by injecting large amounts
of reactive power during fault recovery [10]. This
thesis examines the use of STATCOMs in wind
farms to stabilize the grid voltage after grid
disturbances such as line outages or severe system
faults.
2. Static Synchronous
(STATCOM)
GTOs as switching device. This explains the name,
static synchronous compensator (STATCOM).
Compensator
STATCOM is an advanced FACTS device that
uses no physical inductor or capacitor for reactive
power support unlike SVC. STATCOM supplies
reactive power by exchanging the instantaneous
reactive power among phases of the AC system
STATCOM uses IGBT, IGCT or GTO as switching
devices. In these switches, both switching ON and
switching OFF events can be controlled. So this
gives two degrees of freedom compared to one
degree of freedom given by thyristors in SVCs.
This makes it faster and more effectively
controllable. Figure 1 presents a typical
STATCOM connected to a medium voltage (MV)
bus. A transformer ‗TR‘ is used to lower down the
voltage from high voltage (HV) bus so that lower
voltage rating can be utilized. It has a capacitor at
dc-link to provide the path for current [1].
Smoothing reactor / transformer is used to reduce
the harmonic content in voltage. The operating time
of STATCOM is 15-30 ms, which is very fast
among all the FACTS devices mentioned above.
Main reason for its fast response is the absence of
any rotating mass and the use of IGBTs, IGCTs or
FIG1.STATIC SYNCHRONOUS
COMPENSATOR (STATCOM)
3. Control of statcom
STATCOM is a static synchronous compensator
operated as shunt connected static VAR
compensator whose inductive or capacitive output
current can be controlled independent of AC
system voltage The STATCOM is having higher
dynamic response than the SVC and no additional
filter network is needed for STATCOM like SVC.
In SVC we have to use capacitor banks to generate
capacitive current and inductive banks to generate
current, where a STATCOM will alone generate
capacitive and inductive current. Under light load
conditions, the controller is used to minimize or
completely diminish line overvoltage; on the other
hand, it can also used to maintain certain voltage
levels under
Heavy loading conditions
4.
Simulation
Results
The performance of Wind Electric Generator under the effect of STATCOM using
MATLAB/SIMULINK shows the schematic configuration of the system under consideration for compensation
with STATCOM. It consists of a grid to which both STATCOM and wind mill is connected. The wind electric
generator acts as a load requiring variable reactive power whenever the real power supplied by the wind mill
changes according to the wind speed, its reactive power requirement also changes. We can analyse the system
behaviour by simulating symmetrical and unsymmetrical faults with STATCOM.
Fig2. Reactive power in wind system
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VOLUME :02 Issue 03 I Paper id-IJIERM-II-III-1201 , June 2015
INTERNATIONAL JOURNAL OF INNOVATION IN ENGINEERING RESEARCH & MANAGEMENT ISSN :2348-4918
Fig3. Bus voltage using statcom in wind system
Fig4 % reactive power in wind system
integrated wind generation using a STATCOM: An
5. Conclusion
experimental
verification,‖
International
In this paper, STATCOM has been proposed for
Conference on Future Power Systems, 16-18 Nov.
the improvement active power of wind system
2005
under different types of fault conditions and
[3] E. Muljadi, C.P. Butterfield, ―Wind Farm
thereby improves the fault ride through capability
Power System Model Development,‖ World
of WEG. From the simulation results we can
Renewable Energy Congress VIII, Colorado, Augconclude that, for all types of faults, the real and
Sept 2004
reactive power variations are identified with and
[4] S.M. Muyeen, M.A. Mannan, M.H. Ali, R.
without STATCOM, and hence stability margin
Takahashi, T. Murata, J. Tamura, ―Stabilization of
can be increased to a great extend by the usage of
Grid Connected Wind Generator by STATCOM,‖
STATCOM. Static Compensator also maintains the
IEEE Power Electronics and Drives Systems, Vol.
active power and stability of the power system. So
2, 28-01 Nov. 2005
that, it can be concluded that STATCOM is a
[5] Z. Saad-Saoud, M.L. Lisboa, J.B. Ekanayake,
perfect candidate for improving ride through
N. Jenkins, G. Strbac, ―Application of STATCOMs
capability of wind system which is the necessary
to wind farms,‖ IEE Proceedings – Generation,
requirement to meet new grid codes when
Transmission, Distribution, vol. 145, pp.1584-89,
integrating renewable energy to the grid. it has a
Sept 1998
fast dynamic response show in fig 2 .3.4
[6] L. Chun, J. Qirong, X. Jianxin, ―Investigation of
Voltage Regulation Stability of Static Synchronous
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INTERNATIONAL JOURNAL OF INNOVATION IN ENGINEERING RESEARCH & MANAGEMENT ISSN :2348-4918
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