12
International Journal of Advanced Research in Computer Engineering & Technology (IJARCET) Volume 4 Issue 9, September 2015 3654 ISSN: 2278 1323 All Rights Reserved © 2015 IJARCET IDENTIFICATION AND MITIGATION OF POWER QUALITY DISTURBANCES USING IUPQC BASED ON PSODV TECHNIQUE SK.Abdul Khaleel 1 , B.MaheshBabu 2 , Dr.L.Ravi Srinivas 3 , Dr.S.S.Tulasi Ram 4 M-Tech Scholar [PEED] Dept.of EEE, Gudlavalleru Engineering College, Gudlavalleru, Andhra Pradesh, India 1 Assistant Professor, Dept. of EEE, Gudlavalleru Engineering College, Gudlavalleru, Andhra Pradesh, India 2 Professor, Dept. of EEE, Gudlavalleru Engineering College, Gudlavalleru, Andhra Pradesh, India 3 Professor, Dept. of EEE, JNTU Hyderabad, Hyderabad, Telangana, India 4 -------------------------------------------------------------------------***-------------------------------------------------------------------- Abstract: The concept of power quality has become one of the major concern in today’s electrical power system. The main causes of distortion in power quality is with voltage variations and harmonic currents. To mitigate these power quality problems, usage of Active power conditioner in utility power systems is one of the solution. Interline unified power quality conditioner (IUPQC) was widely studied by many researchers as an eventual active power conditioner to improve power quality of two feeders in a transmission line of a power system. The interline unified power quality conditioner (IUPQC) consists of series and shunt active filters connected in between two transmission line. The reference current generation is carried out by instantaneous active power (PQ) theory for shunt active filter and synchronous reference frame (SRF) theory for series active filter. Further the effective is enhanced with partical swarm optimization with differential velocity (PSO+DE) optimization technique. The gating pulses for VSI’s of active power conditioner are generated by hysteresis band current control. The effective simulations are carried out in Mat lab/Simulink. Keywords: Power Quality (PQ),Total Harmonic Distortion (THD),Interline Unified Power Quality Conditioner(IUPQC), Particle Swarm Optimization with Differential Velocity (PSODV). I. INTRODUCTION power quality problems have received a great attention nowadays are mainly named as harmonic currents and voltage variations. The non-linear loads like (power electronic devices) is connected in load side harmonic currents will occurred. voltage variations (sag & swell) are occurred due to energization of heavy loads. These harmonic currents & voltage variations are mitigated by shunt & series active power filters. The reference currents are generated with the control strategy instantaneous active and reactive power (PQ) theory in one feeder line. and the synchronous reference frame (SRF) theory in another feeder line. The pi controller can be optimized with new optimization technique particle swarm optimization with differential velocity (PSO+DE).This paper can be explained by a new connection of UPQC to improve the power quality of two feeder lines in a distribution system. The UPQC is connected between two different feeders (lines), this connection of UPQC will be called an IUPQC. II.INTERLINE UNIFIED POWER QUALITY CONDITIONER (IUPQC): IUPQC is relatively new member of custom power device. It is a combination of shunt and series compensators. Fig:1. typical IUPQC connected in a distribution system

IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

Embed Size (px)

Citation preview

Page 1: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3654 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

IDENTIFICATION AND MITIGATION OF

POWER QUALITY DISTURBANCES USING

IUPQC BASED ON PSODV TECHNIQUE SK.Abdul Khaleel

1, B.MaheshBabu

2, Dr.L.Ravi Srinivas

3, Dr.S.S.Tulasi Ram

4

M-Tech Scholar [PEED] Dept.of EEE, Gudlavalleru Engineering College, Gudlavalleru, Andhra Pradesh, India1

Assistant Professor, Dept. of EEE, Gudlavalleru Engineering College, Gudlavalleru, Andhra Pradesh, India 2

Professor, Dept. of EEE, Gudlavalleru Engineering College, Gudlavalleru, Andhra Pradesh, India3

Professor, Dept. of EEE, JNTU Hyderabad, Hyderabad, Telangana, India4

-------------------------------------------------------------------------***--------------------------------------------------------------------

Abstract: The concept of power quality has become one

of the major concern in today’s electrical power system.

The main causes of distortion in power quality is with

voltage variations and harmonic currents. To mitigate

these power quality problems, usage of Active power

conditioner in utility power systems is one of the

solution. Interline unified power quality conditioner

(IUPQC) was widely studied by many researchers as an

eventual active power conditioner to improve power

quality of two feeders in a transmission line of a power

system. The interline unified power quality conditioner

(IUPQC) consists of series and shunt active filters

connected in between two transmission line. The

reference current generation is carried out by

instantaneous active power (PQ) theory for shunt active

filter and synchronous reference frame (SRF) theory

for series active filter. Further the effective is enhanced

with partical swarm optimization with differential

velocity (PSO+DE) optimization technique. The gating

pulses for VSI’s of active power conditioner are

generated by hysteresis band current control. The

effective simulations are carried out in Mat

lab/Simulink.

Keywords: Power Quality (PQ),Total Harmonic

Distortion (THD),Interline Unified Power Quality

Conditioner(IUPQC), Particle Swarm Optimization

with Differential Velocity (PSODV). I. INTRODUCTION

power quality problems have received a great

attention nowadays are mainly named as harmonic

currents and voltage variations. The non-linear loads

like (power electronic devices) is connected in load

side harmonic currents will occurred. voltage

variations (sag & swell) are occurred due to

energization of heavy loads. These harmonic currents

& voltage variations are mitigated by shunt & series

active power filters. The reference currents are

generated with the control strategy instantaneous

active and reactive power (PQ) theory in one feeder

line. and the synchronous reference frame (SRF)

theory in another feeder line. The pi controller can be

optimized with new optimization technique particle

swarm optimization with differential velocity

(PSO+DE).This paper can be explained by a new

connection of UPQC to improve the power quality of

two feeder lines in a distribution system. The UPQC

is connected between two different feeders (lines),

this connection of UPQC will be called an IUPQC.

II.INTERLINE UNIFIED POWER QUALITY

CONDITIONER (IUPQC):

IUPQC is relatively new member of custom

power device. It is a combination of shunt and series

compensators.

Fig:1. typical IUPQC connected in a distribution

system

Page 2: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3655 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

Interline unified power quality conditioner consists of

two voltage source converters (VSC-1 and VSC-2)

which are connected back to back through a common

dc capacitor Cdc. VSC-1 is connected in shunt

instantaneous active and reactive power (PQ) theory

with feeder-1 while VSC-2 is placed in series

synchronous reference frame (SRF) theory with

feeder2. In this fig.1 the feeder impedances are

denoted by the pairs (Rs1, Ls1) and (Rs2, Ls2) it can be

seen that the two feeder supply loads L-1 and L-2.

The load L-1 is assumed to have non-linear load. It is

further load L-2 is assumed to have linear load. The

shunt VSC-1 is connected to bus B-1at the end of

feeder-1.while the series VSC-2 is connected to bus

B-2 at the end of feeder-2. and across sensitive load

terminals Vt1 and Vt2 respectively.

Fig :2 single line diagram of IUPQC

The single line diagram of IUPQC is shown in fig.2.

Basically IUPQC is nothing but the device UPQC

kept in between two individual feeders like feeder-1

and feeder-2. Which are connected to two different

substations, Supply the system loads L-1 and L-2.

The supply voltages are denoted by Vs1 and Vs2. The

voltages which are denoted by Vt1 and Vt2,

respectively. The IUPQC is to hold the voltages Vt1

and Vt2 constant against voltage sag and voltage swell

etc. in either of the two feeders it has been

demonstrated that the IUPQC can absorb power from

one feeder (say feeder-2) to hold Vl constant in case

of a sag in the voltage Vs2. This can be accomplished

as the two VSCs are supplied by a common DC

capacitor.

III.CONTROL STRATAGY FOR IUPQC

PQ theory is a inherently 3-phase theory and

These control strategy can be used for the generation

of reference source currents. Inputs of the

Instantaneous active and reactive power theory (p–q

theory) are load side harmonic currents, source

voltages and loss component current from the dc link

voltage control. The concept of instantaneous

reactive power theory (p-q theory) method basically

consists of a variable transformation from the a, b, c

reference frame of the instantaneous power, voltage

and current signals to the α − β reference frame. The

conversion formulae of voltages and currents are

given be side

1)120sin()120sin(sin

)120cos()120cos(cos3/2

cib

i

ai

i

i

2)120sin()120sin(sin

)120cos()120cos(cos3/2

cub

u

au

u

u

The instantaneous active and reactive power can be

expressed by the following system:

3

i

i

uu

uu

ql

lp

The instantaneous active and reactive power can be

decomposed in terms of the dc components plus the

ac components, that is

ppp ~

qqq ~

Where:

p : is the dc component of the instantaneous power

p, and is related to the conventional fundamental

active current.

p~ : is the ac component of the instantaneous power

p, it does not have average value, and is related to the

harmonic currents caused by the ac component of the

instantaneous real power.

Page 3: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3656 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

q : is the dc component of the imaginary

instantaneous power q, and is related to the reactive

power generated by the fundamental components of

voltages and currents.

q~ : is the ac component of the instantaneous

imaginary power q, and is related to the harmonic

currents caused by the ac component of instantaneous

reactive power.

422

1

q

p

vv

vv

vvi

i

The reference currents based on the instantaneous

active and reactive power are determined according

to the flowing equation:

5~

~

2

3

2

1

2

3

2

1

01

3

2

*

*

*

i

i

ic

ib

ia

The block diagram of Instantaneous Active and

Reactive Power Theory (P-Q theory) is shown in

Fig.2.

Fig.3: Instantaneous Active and Reactive Power Theory for Reference Current Generation.

B. SERIES CONTROL FOR SRF THEORY

SRF theory can achieve fast and accurate extraction

of the harmonic content. and These control strategy

can be used for the generation of reference currents

and voltages. Applying an angle transformation is to

convert from a stationary reference frame (a-b-c) to a

synchronously rotating frame (d-q-o) it is nothing but

Parks transformation. And these are converted into

DC quantities. The sine and cosine functions are due

to maintain the synchronization with supply voltage

and current with the help of closed loop feedback

control signal (PLL). That generates signal with the

same frequency and phase angle of the input signal.

PI controller is used in this theory. This (d-q-o) frame

is again converted into (a-b-c) frame to get required

reference currents and voltages.

Page 4: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3657 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

qsV

dsV

osV

2

3

cos )3/2cos( )3/4cos(

sin )3/2sin( )3/4sin(

2/1 2/1 2/1 asV

bsV

csV

)6(

)9(cossin* qsdsa iii

Ids= 2/3 (Iasinθ+Ibsin(θ − 1200))……….(7)

)10()120cos()120sin( 00* qsdsb iii

)8())120cos()120cos(cos(3/2 00 cbaqs iiii

)11()120cos()120sin( 00* qsdsc iii

Fig.4: control block of synchronous reference frame theory

Page 5: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3658 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

C.HYSTERESIS BAND CURRENT CONTROL

Hysteresis current control technique is

employed to design the control part of the APF [8] .The

hysteresis band current controller for active power filter

can be carried out to generate the switching pattern of

the inverter. In this controller actual current is forced to

track the sine reference within hysteresis band by back

and forth (or bang-bang) switching of the upper and

lower switches. So the inverter then becomes a current

source, which is controlled within the band and makes

the source current to be sinusoidal.

Fig.5: Hysteresis band current control

The switching takes place when carrier signals crosses

the error signal of iref and iact. Comparision of carrier

signals with the error signal of iref and iact realizes the

PWM switching law described below:

If (iact) > (iref + hb) upper switch of a leg is ON and

lower switch is OFF

If (iact) < (iref + hb) upper switch of a leg is OFF and

lower switch is ON

D. PI CONTROLLER

The reason behind the use of proportional

integral controller is its effectiveness in the control of

steady-state error of a system and also its easy

implementation [6]. However, one disadvantage of this

conventional compensator is its inability to improve the

transient response of the system. In this circuit,

the actual DC capacitor voltage is detected and

compared with the reference value, and the error is

amplified then added to the ilo`ss, the output of high-pass

filter.

Therefore, active power allowed into the capacitor is

being changed and the dc voltage is controlled.

sninssnpnlossnloss vkvvkii )( )1()1()(

Where, )( )1( nssn vv is the error between the

reference (Vdc*) and sensed (Vdc) dc voltage at the nth

sampling instant. Kp and Ki are the proportional and the

integral gains of the dc bus voltage PI controller. The

placement of PI controller is shown in Fig.2 [5].

IV.DESIGN SPECIFICATIONS

Design parameters of IUPQC: DC bus voltage, Dc bus

capacitance, KVA rating of transformer and voltage

rating of series active power filter, and filter design.

a) DC capacitor voltage:

The DC capacitor voltage is calculated based on

following relation

)12())*3(/)*22( mVV LLdc

Where m is modulation index (m=1)

b) DC bus capacitance of the VSC:

The DC bus capacitance is calculated based on how

much of energy is required during the change in load, it

is calculated as

)13()(*2/1 22

1 dcdcdc VVCE

Where Vdc is DC bus voltage and Vdc1 is the minimum

voltage level of dc bus .

sdc VV *21

)(2/1* 2

2

2

1 dcdcdc VVCtP

P*∆t = 1/2*Cdc (Vdc12 –Vdc

2)

Where ss IVP **3

)14()/()*(*2 22

1 dcdcdc VVtpC

c) kVA rating of transformer: The kVA rating of

transformer is calculated as

)15(1000/)*3( ss IVS

d) Voltage rating of series active power filter: The

voltage rating of VSC depends on maximum voltage to

be injected under the case any voltage variations of the

load. .The injected voltage is calculated as a

)16()( 22 DVRLsinj VVVV

e) Ripple Filter: In order to eliminate the switching

frequency ripples from injected

Page 6: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3659 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

voltage the ripple filter is designed. Ripple filter

consists a series connected Rr and Cr.

)17()**2/(1 rrr CRf

Where fr is taken as half of the Switching frequency.

The range of switching frequency is from 5KHz –

20KHz.

Table1: Parameters of IUPQC

Parameters Ratings

AC line voltage 415V,50Hz

Reference dc link

capacitance

1200 µF

Reference dc voltage 880V

Line impedance Ls =3mH,Rs=0.01Ω

Ripple filter Cf=10μF,Rf =4.8Ω

DC voltage of series apf 300V

PWM switching

frequency

10kHz

Series Transformer 10kVA,200V/300V

V. OPTIMIZATION OF PI CONTROLLER USING

PARTICLE SWARM OPTIMIZATION WITH

DIFFERENTIAL VELOCITY(PSODV)

PSO-DV introduces a differential operator (borrowed

from the differential evolution) in the velocity-update

scheme of PSO. The operator is invoked on the position

vectors of two randomly chosen particles (population-

members), not on their individual best positions.

Further, unlike the PSO scheme, a particle is actually

shifted to a new location only if the new location yields

a better fitness value, i.e., a selection strategy has been

incorporated into the swarm dynamics. In the proposed

algorithm, for each particle i in the swarm two other

distinct particles, say j and k (i j k), are

selected randomly. The difference between their

positional coordinates is taken as a difference vector:

jk XX

(18)

Then the d-th velocity component (1 < d < n) of the

target particle i is updated as

otherwisetV

CRrandiftXPCtVtV

id

idgddidid

)(

)1,0()),(.(..)(.)1( 22

( 19)

where CR is the crossover probability, d is the d-th

component of the difference vector defined earlier, and

is a scale factor in [0, 1]. In essence, the

cognitive part of the velocity update formula is replaced

with the vector differential operator to produce some

additional exploration capability. Clearly, for 1CR ,

some of the velocity components will retain their old

values. Now, a new trial location riT is created for the

particle by adding the updated velocity to the previous

position Xi:

)1()( tVtXT iiri

(20)

The particle is placed at this new location only if the

coordinates of the location yield a better fitness value.

Thus if we are seeking the minimum of an n

dimensional function )(Xf , then the target particle is

relocated as follows:

otherwisetXtX

tXfTfifTtX

ii

iririi

)()1(

))(()()1(

(21)

Page 7: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3660 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

Therefore, every time its velocity changes, the particle

either moves to a better position in the search space or

sticks to its previous location. The current location of

the particle is thus the best location it has ever found

with respect to the previous locations. In other words,

unlike the classical PSO, in the present scheme, Plid

always equals Xid. So the cognitive part of the algorithm

involving |Plid-Xid| is automatically eliminated in our

algorithm. If a particle gets stagnant at any point in the

search space (i.e., if its location does not change for a

predetermined number of iterations), then the particle is

shifted by a random mutation (explained below) to a

new location. This technique helps escape local minima

and also keeps the swarm “moving”:

)))(()(....)2()1()((( NtXfandNtXtXtXtXif iiiii

then

for (r=1to n)

)()1,0()1( minmaxmin XXrandXNtX rir

(22)

where f * is the global minimum of the fitness

function, N is the maximum number of iterations up to

which stagnation can be tolerated and (Xmax, Xmin)

define the permissible bounds of the search space.

Price and Storn formulated the working principle of the

DE with a simple strategy in [32]. Later on, they

suggested ten different strategies of the DE [49].

Strategy-7 (DE/rad/1/bin) is the most successful and

widely used strategy. The key control parameters in DE

are population size (NP), scaling factor (F) and

crossover constant (CR). Tuning of PI controller with

PSODV is represented as below Fig (6)

Fig.6. Tuning of PI with PSODV

The flow chart representation of PSODV algorithm is as

shown in Fig (7)

Fig (7):flowchart of PSODV algorithem

Page 8: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3661 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

VI. SIMULATION RESULTS OF IUPQC WITH PSODV

In the above figure is interline unified power quality conditioner simulated in MATLAB software here one of the

transmission line connected in shunt PQ theory of non linear load and another transmission line connected in series SRF

theory of linear load in that simulation of matlab results are shows in below

Fig:1 harmonic compensating currents after the application of iupqc

A 3-phase supply of 415v line to line 50hz with different disturbances at source end, Non-linear load (whether

diode rectifier feeding an RL load ) injects current harmonics in to the system. IUPQC is able to reduce the harmonics

from entering into the system using shunt control after the application of IUPQC with harmonic compensating currents.

0 0.05 0.1 0.15-150

-100

-50

0

50

100

150

Time(in seconds)

harm

onic

com

pens

atin

g cu

rrent

(am

ps)

Page 9: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3662 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

Fig:2 injected currents of statcom

Fig:3 source current

The shunt active filter (PQ) theory and series active filter (SRF) theory has to applied in IUPQC with the help of PSODV

technique the source current is sinusoidal.

0 0.05 0.1 0.15 0.2 0.25 0.3-50

0

50

0 0.05 0.1 0.15 0.2 0.25 0.3-50

0

50

0 0.05 0.1 0.15 0.2 0.25 0.3-50

0

50

Time(in seconds)

inje

cte

d h

arm

on

ic cu

rre

nts

0 0.05 0.1 0.15-150

-100

-50

0

50

100

150

Time(in seconds)

so

urce

cu

rre

nt(a

mp

s)

Page 10: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3663 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

Fig:4 Mitigating the effect of sag of 0.1 p.u with duration 0.1sec to 0.2 sec using PSODV technique with pi controller

A 3-phase supply voltage (415v-50hz) with momentary sag of 0.1 pu magnitude with the duration about 20-30 cycles is

taken .with the system operating in the steady state.

Fig:5 capacitor voltage(vdc)

in order to supply the balanced power required to the load,the dc capacitor voltage raises as soon as the sag

occurs. as the sag is removed the capacitor voltage returns some times to the steady state. The total harmonic distortion

(THD) at load side is found to be 0.191%.the source current thd was effectively found to be 3.23%.

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5-1

0

1

so

urce

vo

lta

ge

(p

.u)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-1

0

1

inje

cte

d v

olta

ge

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5-1

0

1

Time(in seconds)

loa

d v

olta

ge

(p

.u)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

100

200

300

400

500

600

700

800

900

1000

Time(in seconds)

dc lin

k v

olta

ge

%<vdc>

Page 11: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3664 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

VII. DEVELOPING OF PROPOSED ALGORITHM

The proposed algorithm ensures that the

minimum VA loading is obtained by controlling the

voltage sag using PSODV with constraints on THD

of load voltage and THD of source current. The main

objective of controlling the injected voltage is

accomplishing the precise compensation of the

harmonic component.

This section describes the total harmonic

distortion of IUPQC with PI regulator the source

current THD is 5.45% which is shown in fig (8).

Fig.8.THD source current with IUPQC using PI

controller

In these another section describes the total

harmonic distortion of IUPQC with PI regulator the

load voltage THD is 2.37% which is shown in fig (9).

Fig.9.THD load voltage with IUPQC using PI

controller

With IUPQC PI-PSODV controller the

illustration of THD in source current which is

reduced to 3.23% by making KP=7.3233 KI=15.6799

shown in fig (10).

Fig.10.THD of source current with IUPQC using PI-

PSODV controller.

With IUPQC PI-PSODV controller the

illustration of THD in load voltage which is reduced

to 0.09% by making KP=0.5000 KI=2.4171 shown in

fig (11).

Fig.11.THD of load voltge with IUPQC using PI-

PSODV controller.

The convergence of THD in load voltage

and source current IUPQC with PSODV is

illustrated as shown in fig (10) and fig(11). The

optimization has been run for 0 to 100 iterations. The

parameters of PSO are given in table 3.

Table3: Parameters of PSODV

Parameters Values

Population size 10

No.of iterations 100

CR and CF 0.8 and 0.5

From the knowledge of PQ theory & SRF

theory the kp and ki values are tuning with PSODV

optimization technique. No of populations=5 No of

iterations=100 Cr=0.8 f=0.5 (constant) C1 and c2 are

varying

Table4: Results of PSODV

C1 C2 GLOB

LE

FIT

(THD)

KP1 KI1 KP2 KI2

2.

5

1.5 0.0203

5.703

2

10.947

8

7.060

5

0.636

7

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

0

50

100

Selected signal: 25 cycles. FFT window (in red): 25 cycles

Time (s)

0 20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

Frequency (Hz)

Fundamental (50Hz) = 15.76 , THD= 5.45%

Mag (%

of F

undam

ental

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-0.5

0

0.5

Selected signal: 25 cycles. FFT window (in red): 25 cycles

Time (s)

0 20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

Frequency (Hz)

Fundamental (50Hz) = 0.9397 , THD= 2.37%

Mag (%

of F

undam

ental)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

0

50

100

Selected signal: 25 cycles. FFT window (in red): 25 cycles

Time (s)

0 20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

Frequency (Hz)

Fundamental (50Hz) = 12.28 , THD= 3.23%

Mag (

% o

f F

undam

enta

l)

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-0.5

0

0.5

Selected signal: 25 cycles. FFT window (in red): 25 cycles

Time (s)

0 20 40 60 80 100 120 140 160 180 2000

20

40

60

80

100

Frequency (Hz)

Fundamental (50Hz) = 0.7897 , THD= 0.09%

Mag (%

of F

undam

ental)

Page 12: IDENTIFICATION AND MITIGATION OF POWER …ijarcet.org/wp-content/uploads/IJARCET-VOL-4-ISSUE-9-3654-3665.pdf · IDENTIFICATION AND MITIGATION OF ... connection of UPQC to improve

International Journal of Advanced Research in Computer Engineering & Technology (IJARCET)

Volume 4 Issue 9, September 2015

3665 ISSN: 2278 – 1323 All Rights Reserved © 2015 IJARCET

1.

0

3.0 0.0211

8.657

3

16.297

8

9.502

2

0.688

9

3.

5

0.5 0.0196

7.230

2

12.678

1

6.073

8

3.894

9

1.

5

2.5 0.0191

2.438

0

13.503

4

8.002

8

2.837

7

The multi objective function is

F = f(THD of source current)+f(THD of load

voltage)

For Kp1 = 2.4380; Ki1 =13.5034; KP2 =8.0028; Ki2

=2.8377

The overall THD has been reduced to 0.0191

for CR=0.8 , F=0.5 for population size 10 and

number of iterations are taken as 100.

Fig.12. THD convergence graph

Table4: THD of IUPQC with PSODV

Controller THD of source

current

THD of load

voltage

With PI 5.45 3.23

With

PSODV

2.37 0.09

VIII. CONCLUSION

A suitable mathematical model of the IUPQC ha

been developed with shunt (pi) controller and series

voltage controller the simulated results have been

described. the simulated results shows that pi controller of the shunt active filter, series active filter

compensates of all types of interruptions in the load

current and source voltage, so as to maintain

sinusoidal voltage and current at load side. Finally

the conventional PI controller and Particle Swarm

Optimization with Differential Evolution (after

running better result of 10 times) showed that

PSODV has been proved to be better in terms of

harmonic reduction in source current. The main aim of IUPQC is to mitigate the current harmonics in one

of the feeder line and to control the voltage sag in

another feeder line.

Finally the source current will be sinusoidal and load voltage also sinusoidal using IUPQC device

based on PSODV optimization technique. for all

types of disturbances (interruptions) the total

harmonic distortion (THD)after compensation is to

be lessthan 5% which is as per IEEE standereds.

IX. REFERENCES

[1] F. Z. Peng and J. S. Lai, “Generalized instantaneous reactive

power theory for three-phase power systems,” IEEE Trans.

Instrum. Meas., vol. 45, no. 1, pp. 293–297, Feb. 1996.

[2] G. Ledwich and A. Ghosh, “A flexible DSTATCOM operating

in voltage and current control mode,” Proc. Inst. Elect. Eng.,

Gen., Transm. Distrib., vol. 149, no. 2, pp. 215–224, 2002.

[3] M. K. Mishra, A. Ghosh, and A. Joshi, “Operation of a

DSTATCOM in voltage control mode,” IEEE Trans. Power Del.,

vol. 18, no. 1, pp. 258–264, Jan. 2003.

[4] N. H. Woodley, L. Morgan, and A. Sundaram, “Experience

with an inverter-based dynamic voltage restorer,” IEEE Trans.

Power Del., vol. 14, no. 3, pp. 1181–1186, Jul. 1999.

[5] A. Ghosh, A. K. Jindal, and A. Joshi, “Design of a capacitor-

supported Dynamic Voltage Restorer (DVR) for unbalanced and

distorted loads,” IEEE Trans. Power Del., vol. 19, no. 1, pp. 405–

413, Jan. 2004.

[6] F. Kamran and T. G. Habetler, “Combined deadbeat control of

a seriesparallel converter combination used as a universal power

filter,” IEEE Trans. Power Electron., vol. 13, no. 1, pp. 160–168,

Jan. 1998.

[7] H. M. Wijekoon, D. M. Vilathgumuwa, and S. S. Choi,

“Interline dynamic voltage restorer: an economical way to

improve interline power quality,” Proc. Inst. Elect. Eng., Gen.,

Transm. Distrib., vol. 150, no. 5, pp. 513–520, Sep. 2003.

[8] A. Ghosh, A. K. Jindal, and A. Joshi, “A unified power quality

conditioner for voltage regulation of critical load bus,” in Proc.

IEEE Power Eng. Soc. General Meeting, Denver, CO, Jun. 6–10,

2004.

[9] A. Ghosh and G. Ledwich, “A unified power quality

conditioner (UPQC) for simultaneous voltage and current

compensation,” Elect. Power Syst. Res., vol. 59, no. 1, pp. 55–63,

2001.

[10] A. Ghosh, G. Ledwich, O. P. Malik, and G. S. Hope, “Power

system stabilizer based on adaptive control techniques,” IEEE

Trans. Power App. Syst., vol. PAS-103, no. 8, pp. 1983–1989, Aug.

1984.

0 10 20 30 40 50 60 70 80 90 1000.019

0.0195

0.02

0.0205

0.021

0.0215

0.022

0.0225

0.023

0.0235

no of iterations

percenta

ge o

f th

d

C1=3.5 C2=0.5

C1=1 C2=3

C1=2.5 C2=1.5

C1=1.5 C2=2.5

CR=0.8 F=0.5(CONT)