ABSTRACT:
STATCOM
(static synchronous compensator) as a shunt-link flexible AC transmission system(FACTS)
controller has shown extensive feasibility in terms of cost-effectiveness in a
wide range of problem solving abilities from transmission to distribution
levels. Advances in power electronic technologies such as Voltage Source Converter
(VSC) improves the reliability and functionality of power electronic based
controllers hence resulting in increased applications of STATCOM. In this
paper, design and implementation of a Distribution type, Voltage Source Converter
(VSC) based static synchronous compensator (DSTATCOM) has been carried out. It
presents the enhancement of power quality problems, such as voltage sag and
swell using Distribution Static Compensator (D-STATCOM) in distribution system.
The model is based on Sinusoidal Pulse Width Modulation (SPWM) technique. The
control of the Voltage Source Converter (VSC) is done with the help of SPWM.
The main focus
of this paper is to compensate voltage sag and swell in a distribution system.
To solve this problem custom power devices are used such as Fixed Compensators (FC,
FR), Synchronous Condenser, SVC, SSSC, STATCOM etc. Among these devices Distribution
STATCOM (DSTATCOM) is the most efficient and effective modern custom power
device used in power distribution networks. DSTATCOM injects a current into the
system to mitigate the voltage sag and swell. The work had been carried out in MATLAB
environment using Simulink and SIM power system tool boxes. The proposed D-STATCOM
model is very effective to enhance the power quality of an isolated
distribution system feeding power to crucial equipment in remote areas. The simulations
were performed and results were found to be satisfactory using MATLAB/SIMULINK
KEYWORDS:
1.
Statcom
2.
Facts Controllers
3.
D-Statcom
4.
Voltage Source Converter
5.
Total Harmonic Distortions
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.1
Schematic diagram of D-STATCOM
EXPECTED SIMULATION RESULTS:
Fig.2
Three Phase to Ground -Voltage at Load Point is 0.6600 p.u
Fig.3
Double Line to Ground- Voltage at Load Point is 0.7070 p.u
Fig.4 Line to Line- Voltage at Load
Point is 0.7585
Fig.5 Single Line to Ground- Voltage at
Load Point is 0.8257
Fig.6
The waveforms shows THD (41.31%) results of fixed load and variable inductive
load.
Fig.7
The wave forms shows THD (21.28%) results of fixed load and variable capacitive
load
Fig.8 Three Phase to Ground-Voltage at
Load Point is 0.9367 p.u
Fig.9 Double Line to Ground- Voltage at
Load Point is0.9800 p.u
Fig.10 Line to Line- Voltage at Load
Point is 1.068
Fig.11 Single Line to Ground - Voltage
at Load Point is 0.9837
Fig.12 The waveform for pure
inductive,capacitive loads with statcom
Fig.13 The waveform for without filter
THD results 41.31%
Fig.14 The above waveform for with
filter THD results 1.11%
CONCLUSION:
The simulation results show that the
voltage sags can be mitigate by inserting D-STATCOM to the distribution system.
By adding LCL Passive filter to D-STATCOM, the THD reduced. The power factors
also increase close to unity. Thus, it can be concluded that by adding DSTATCOM
with LCL filter the power quality is improved.
REFERENCES:
[1] A.E. Hammad, Comparing the Voltage
source capability of Present and future Var Compensation Techniques in Transmission
System, IEEE Trans, on Power Delivery. Volume 1. No.1 Jan 1995.
[2]
G.Yalienkaya, M.H.J Bollen, P.A. Crossley, “Characterization of Voltage Sags in Industrial Distribution System”,
IEEE transactions on industry applications, volume 34, No. 4,
July/August, PP.682-688, 1999
[3]
Haque, M.H., “Compensation of Distribution Systems Voltage
sags by DVR and D STATCOM”, Power Tech
Proceedings, 2001 IEEE Porto, Volume 1, PP.10-13, September
2001.
[4] Anaya-Lara O, Acha E., “Modeling and Analysis Of Custom Power Systems
by PSCAD/EMTDC”, IEEE Transactions on Power Delivery, Volume
17, Issue: 2002, Pages: 266 272.
[5]
Bollen, M.H.J.,”Voltage sags in Three Phase Systems”, Power Engineering
Review, IEEE, Volume 21, Issue: 9, September 2001, PP: 11-
