1. POWER QUALITY IMPROVEMENT IN A
PV DISTRIBUTION SYSTEM BY USING
D-STATCOM
Guide : Prof. S.SRIKANTH
PROFESSOR
1

2. ABSTRACT:
The main aim of this paper is the voltage regulation
& power quality which is the most important
operational requirements in power network at both
transmission and distribution levels. Whenever
there is a penetration of photovoltaic cell power to
the low voltage distribution grid, there occur the
problem of mismatch in voltage and frequency in
the network, perhaps caused by non linear
loads, generating harmonics. In this D-STATCOM is
used to improve the voltage regulation thereby the
power system stability.
2

3. OBJECTIVES

To analyze the effect of non-linear loads on power
system.

To study different methods already proposed for
mitigation
of
harmonics
due
to
nonlinear loads.

To propose a Best way to mitigate the current
harmonics and reactive power compensation.
3

4. CONTENTS:

Introduction

Operation Of D-STATCOM

Proposed Topology

Photovoltaic Cell

Matlab modeling

References
4

5. INTRODUCTION
 In today’s scenario power quality maintenance in a power
system is very essential because of the increase in different types
of loads that pollute power systems.

The use of the power electronic devices in power distribution
system gives rise to harmonics and reactive power disturbances.
o
A voltage dip will occur, if the reactive power is consumed from
the grid, this affects other sensitive loads which are connected to
the grid.

Hence compensation is necessary for these types of loads for
requiring reactive power.
5

6. 
There are two approaches to the mitigation of power quality
problems.
1. load conditioning 2. line-conditioning

Passive filters have been most commonly used to limit the
flow of harmonic currents in distribution systems.

The performances of Conventional method (LC filter) is
not satisfactory due to the drawbacks

Among the different new technical options available to
improve power quality, D-STATCOM have proved to be an
important and flexible alternative to compensate for current
and voltage disturbances in power distribution systems.
6

7. DISTRIBUTION NETWORK
Simple line presentation of generating distribution network
7

8. DISTRIBUTION STATIC SYNCHRONOUS
COMPENSATOR (D-STATCOM)
oD-STATCOM is the most important controller for distribution networks. It
has been widely used to precisely regulate system voltage, improve
voltage profile, reduce voltage harmonics, reduce transient voltage
disturbances and load compensation.
oD-STATCOM uses a power-electronics converter to synthesize the
reactive power output.
oA D-STATCOM converter is controlled using pulse width modulation
(PWM) or other voltage/current-shaping techniques .
8

9. General Topology
 D-STATCOM controllers can be constructed based on both voltage source
inverter (VSI) topology and current source inverter (CSI) topology
 In practice, CSI topology is not used for D-STATCOM. The reason for this is
related to the higher losses on the DC reactor of CSI compared to the DC
capacitor of VSI.
 VSI-based topology has the advantage because an inductance of a coupling
transformer Tr (if present) can constitute, partially or completely, the inductance of
AC filter
The VSI converters for D-STATCOM are constructed based on multi-level
topologies, with or without use of a transformer. These solutions provide support
for operation with a high level of terminal voltage
9

10. OPERATION OF D-STATCOM
General topology of VSI-based and CSI-based DSTATCOM
10

11. Configuration of D-STATCOM
11

12. PHOTOVOLTAIC CELL:

A PV system consists of a number of interconnected
components.

At present, photovoltaic (PV) generation is assuming
increased
importance
as
renewable
energy
Sources(RES) application because of advantages such
as simplicity of allocation, high dependability, absence of
fuel cost, low maintenance and lack of noise and wear
due to the absence of moving parts.

There are two main system configurations
1. stand-alone PV system
2. stand-alone and grid-connected
12

13. Schematic Diagram of Grid-Connected PV System
13

14. STAND-ALONE AND GRID-CONNECTED SYSTEM
Schematic diagram of grid-connected photovoltaic system
14

15. THREE-PHASE GRID-CONNECTED PHOTOVOLTAIC ENERGY
CONVERSION SYSTEM:
Open circuit voltage
Light generated current
Reverse saturation current
Short circuit current
Irradiation
Mathematical model for PV
cell
15

16. MATLAB/SIMULINK MODEL OF PROPOSED GRID
CONNECTED PV SYSTEM WITH OUT D-STATCOM
16

17. SIMULATED OUTPUT WAVE FORMS OF SOURCE
VOLTAGE, SOURCE CURRENT, LOAD CURRENT WITH
OUT COMPENSATOR
17

18. SIMULATION SHOWING NON UNITY POWER
FACTOR WITH OUT D-STATCOM
18

19. MATLAB/SIMULINK MODEL OF PROPOSED GRID
CONNECTED PV SYSTEM WITH D-STATCOM
19

20. SIMULATED OUTPUT WAVE FORMS OF SOURCE
VOLTAGE, SOURCE CURRENT, LOAD CURRENT WITH
COMPENSATOR
20

21. SIMULATION SHOWING UNITY POWER FACTOR BY
USING D-STATCOM
21

22. CONCLUSION
In this paper we have modeled and analyzed the PV
(photovoltaic) power system is being integrated with DStatcom to low voltage power distribution grid at consumer
end to compensate the harmonics coming from grid side
inverter and other side we have different loads in
that, most of the unbalanced nonlinear loads injects
harmonic currents to source side and effects the source
current. By using D-Statcom, the source current does not
effect. In this, we have studied and analyzed the operation
and performance of D-statcom at unbalanced non linear
load condition and also gives the comparison by using with
and without D-statcom. This proposed model is
implemented using MATLAB SIMULINK software and the
obtained resultant waveforms are evaluated and system
stability effectiveness and power system performance
have been established.
22

23. REFERENCE:







[1]. Furuhashi.T, S.Okuma, Y. Uchikawa, “a study on the theory of
instantaneous
reactive
power”,
IEEE
Trans.
Industrial
Electronics, , vol.37, No. 1, pp. 86-90, 1990.99
[2].Ghosh A., G..Ledwich, “Load compensating DSTATCOM in weak
ACsystem”, IEEE Trans. Power Delivery, vol.18, No. 4, pp. 13021309,2003.
[3]. Hingorani NG, Gyugyi L. Understanding FACTS. Concepts and
Technology of Flexible AC Transmision Systems. New York: IEEE
Press, 19
[4]. H Akagi . Active Filters and Energy Storage Systems for Power
Conditioning in Japan. Proc. of First International Conference on Power
Electronics Systems and Application, 2004; 80–88.
[5]. J. Solanki and B. Singh , "A Comparison of Control Algorithms for
dstatcom" ieee t ransactions on industrial elect ronics, VOL.
56, NO.7, mL Y 2009.
[6]. Ledwich.G , A.Ghosh,. “Power Quality Enhancement Using
CustomPower Devices”, Kluwer Academic Publisher, 2002.
[7]. Papic I, Blazic B,. Improved D-STATCOM Control for Operation with
UnbalancedCurrents and Voltages. IEEE Trans. Power Delivery, Vol.
23
21, No. 1, 2006; 225–233.

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