 Open Access
 Authors : Challa Krishna Rao, Dipendra Prasad Yadav
 Paper ID : IJERTCONV8IS16017
 Volume & Issue : NCSMSD – 2020 (Volume 8 – Issue 16)
 Published (First Online): 18102020
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Threearm ACDCDC Automatic Voltage Regulation with Current Ripple Reduction Technique Topology
Challa Krishna Rao
Electrical and Electronic Engineering Aditya Institute of Technology and Management,
Tekkali, A.P
Dipendra Prasad Yadav
Electrical and Electronic Engineering Aditya Institute of Technology and Management,
Tekkali, A.P
AbstractThe aim of this paper is develop the threebranch Alternating current Automatic Voltage Regulator(AVR) with fuzzy logic technique. Based upon this technology AVR controller has been developed and simulated to decrease the switching power losses across the switches. The proposed fuzzy controller based AVR has the ability of producing the sinusoidal output current with better output voltage regulator. This three branch power convertor circuit acts as an AC step up (boost ) converter when the supply voltage is less than the load voltage and acts as an Alternating current step down (buck ) converter when the supplied voltage is higher than specified value. Hence, the AVR output voltage maintained at a constant value. So, there is no need to use the large Direct current capacitor to withstand the continuous dc voltage. Hence, the size and cost of the converter is decreased and the life of the power converter is increased to analyse the THD.
KeywordsCurrent Buck, Boost, power converter, Automatic Voltage Regulator,THD
merits of decreasing the installation and volume ,as well as improve the reliability and efficiency. The protype is developed and examine.

FUZZY SET THEORY

Fuzzy setDefinition:A fuzzy set is a part of (u,m) where u is a set and m is membership function which is ranges from 01. The reference set (u)is called the universe of discourse such that . The m(x) is the grade value of membership x in (u,m),function = called as membership function fuzzy set and given as
A=(u, m) where u={x1,xn} and m={m(x1),m(xn)} 1

OPERATION OF FUZZY SET :
Two sets A and B the universe of information u and an element of x of universe. The following relation can be performed they are union(OR),intersection(AND) and complement(NOT)

Fuzzy OR operation :let the sets A and B can be represented for OR operation is given by

INTODUCTION
()=
..2
Now, a days the quality of the supplied power is very crucial
such that
b
ngs to u
y elo
to many consumers. The quality power (PQ) is solution and many customer are ready to pay for it. In future, Distribution System operators required orcould decided by the authorities
Where ,V is maximum operation


Intersection operation: the two sets can be related by AND is expressed as
to supply their customers with different power quality level
()=
.3
of the various tariffs. the aim of threebranch AVR acts as
where ,
m
um operation
boost power converter when the source voltage is less than the load voltage i.e. specified voltage and acts as buck power converter when the source voltage is higher than the output load voltage. Hence, the load output voltage is kept at constant level by using the automatic voltage regulator. The load demand is supplied by the conversion output of the power converter circuit acac with conventional threearm power converter which required twice conversion i.e. ACDC and DCAC. The purpose of this power converter is only one conversion. Beside, the power electronic switches a single branch of the threebranch power converter are operate at high frequencies while the other are operated at the lower frequencies. Which decrease the switching power losses and not required the transformer. In differentiation with typical threearm AVR with a continuous bus DC voltage. The bus DC voltage of the proposed threearm AVR is full wave rectified output voltage. Hence, the use of large direct current capacitor withstand a continuous dc voltage is avoided and only small direct current (DC) capacitor is employed to act as snubber and the filter circuit. So, three branch AVR has the
is inim

Fuzzy complement : the complement of degree of membership in (A) is given as
= 1 ()/ .4


CONTROLLER BASED ON FUZZY LOGIC : This controller is algorithm based in which a sets of rules are representing a decision and controlling mechanism to vary response of certain system. The purpose of fuzzy controller system is to replaced the human employment with a rule based fuzzy logic system. This control logic works with algorithm which is developed in the controller unit convert is to performs the certain controlled operation on automatic control strategy based on required by the user. The below figure(1)shows the basic architecture of the fuzzy logic which includes the input module, fuzzification unit, interfacing, Decisioncontrol logic, Defuzzification and output module.
Figure (1):Architecture of fuzzy logic

AUTOMATIC VOLTAGE REGULATOR BASED
ON FUZZY LOGIC :
For develop the AVR based on fuzzy to select the state variable, which indicates the dynamic system. It should take the input signal for controlling. The next, is to select the semantic variable considering in the mind that required number of semantic declared the controlled standard. The compilation ,run time and as well as memory required is also increase. Hence, compromise the computational time is required to select the number of semantic variable. For this test system seven linguistic variables for each input and output variables are needed. Theyare as follows

Large positive

Medium positive

Small positive

Zero

Large negative

Medium negative

Small negative
For normalization is done by dividing the input value by max of the corresponding value of the input variable by open loop simulation. The last, is to determine the membership function of the fuzzy sets. In this paper ,the rulebased system which uses the triangular member ship function for describing the degree of member as shown in figure(2).
Figure(2): Input output membership function of the triangular wave
For designing the AVR the rule are describe by using semantic variables. The two inputs required ,error of deviations and their derivatives results 49 rules for each of the machine. These rules are properly describe in the table(1) below. The standard rules has following structure.
Table(1): standard rules for fuzzy sets
The minimum and maximum technique is used for searching the fuzzy region for each of the rules and follows the intersection (AND) operation which gives the minimum between the two membership function.
Figure(3): The threebranch automatic voltage regulator circuit diagram


CONFIGURATION AND THEORY OF
OPERATION
The proposed circuit is shown in the above figure(3). The threebranch AVR is shown in the figure. This AVR consists of three branches power converter, source inductor, small direct current capacitor and output filter. This AVR act as boost converter when the source voltage is less than the load voltage and acting as a buck converter when the supply voltage is higher than output load voltage hence the converter maintain the specified voltage at constant level so the power converter performs the alternating current boost as well as buck converter which is fully rectified DC output voltage of the AVR. It is different fom the typical threebranch AVRs with a continuous output DC voltage.

Boost mode operation
In this mode of operation the converter acts as boost i.e. when the supply voltage is less than the load voltage. In this condition the first and the third branches are controlled by square wave signal with the fundamental frequency of the utility and the second branch is controlled bypulsewidth modulation technique which employed higher frequency. The below figure(4a) shows the boost operating mode of the converter. The source inductor which is acting as energy storing element. Figure (4 a) shows the positive half cycle operation in boost mode. Here, the switches S1 & S6 are in conduction mode always. Switches S2 & S5 are in off states. When the S3 is at conduction mode and S4 is in off state. The
source voltage makes the inductor to energies during the period S1 and S3. The voltage is given as
= 5
Where , =
=
Figure(4a):circuit diagram for AVR for and AC boost mode for positive cycle
The current through inductor is increase and make the conduction of the S2 and S4 to the dc capacitor of the converter when S3 is nonconducting mode and S4 is in conduction mode. The voltage across inductor is given by
= ..6
, =
Hence, the output voltage is higher than the input source
voltage under the boost mode power converter, the inductor current is reduced .for continuous mode of current is flowing through Volt sec balance from faradays law is given by
(1 ) = 07
D is the duty cycle ratio ,T is time period of the S3. Form the 4 the gain of the converter is given by
wave signal with the fundamental frequency. The 3rd branch is controlled by the pulse width modulation technique which use the higher frequency. The is acting as energy storing element when the power converter is operated in buck mode. The below figure(5 a) shows the operation of the buck under the positive half cycle of the input source voltage. The switch S1 & S4 is in conduction mode always and S2 and S3 is in nonconduction mode always. The 1st and 2nd branch is used to rectified the input source and appearing as bus DC voltage.
& is acting as the LCLPF. When S5 is on and S6 is in off,then stores the energy from the dc bus via S4 and S5. In this period load side inductor voltage becomes
= 0 ..11
Where, 0 is the output load voltage
Figure(5 a): proposed circuit diagram for positive half cycle of buck converter
> 0 in this period stores the max energy in the inductor and discharge through the path S4 & S6 when S5 is off and S6 is on. The voltage across inductor becomes
= 1
1
8
= 0 12
The operation of the DCDC boost converter is same as that of an AC boost during negative halfcycle. As shown in the figure (4b) having the same gain and the ripple current factor is given by
For continuous current flowing through the inductor makes the voltsecbalance according to faradays low and given as
0 = 0 ..13
Where, T and D are the duration of switching and duty ratio
=
..9
,
of S6 respectively. The gain dropped becomes
= ..14
For negative half cycle of input voltage as shown in the
Which depends on the duty cycle ratio the minimum value of the inductor is given by
figure(5 b) .S2 & S3 are in always in conduction mode, while S1 & S4 are in off state always. The 1st and 2nd branch is used
=
(1)2
..10
for rectification which is utilized by the
to stores the
2
Where, F is switching frequency ,Z is the load impedance, the
and are the low pass LC filter to reduce the harmonic of the DC capacitor voltage which is tens of the can be used .
energy via S3&S6 when S5 is off and S6 is on. The stored energy is discharge through S3&S5 when S5 is conducting and S6 is nonconducting mode. It is same as the operation of the negative half DCDC buck converter. Hence ,the output voltage is less than the input source voltage of the three branch power converter circuit.
The minimum value of inductor for continuous conduction mode is given by
= (1) ..15
2
And the ripple output load voltage is given by
Figure(4 b ): for negative half cycle AVR proposed circuit diagram

Buck mode operation
When the input voltage is greater than the output load voltage,the buck power converter is used for step down of the voltage. Here, the 1st and 2nd branch is controlled by square
0
= (0) 82
16
function is carried out with the help of the fuzzy logic based controller
Figure(5 b): AVR proposed circuit diagram for negative half cycle of buck converter


SIMULINK MODEL OF THE SYSTEM
The Simulink model of the system is shown in the figure(6) which is proposed by AVR. It consists of input voltage selection unit, output load voltage processing unit ,and the selection unit. The square wave signal is generated form the input source which uses the voltage sensor. These, signal is usually operated at low frequency. The output form the voltage sensor is passed to the Zerocrossing phase detector and the synchronization is done by inverting the signal with the input source. For obtaining the circuit driving signal to S1 and S2 of the 1st branch. The output from voltage sensor is send for selection and generation of signal 1. The signal 1 is used for the operation of the three branch AVR power converter. If the input voltage is less than the input voltage then converter is operated in boost mode, else in buck mode. Here, the input voltage is higher than the output load voltage. The required parameter of threebranch AVR shown in the below table (2) .
Figure (6): Simulink model of the AVR based on fuzzy controller
Input source inductor
0.4e3 H
Load side filter inductor
0.4e3H
Load side capacitor filter
20e6 f
Middle dc capacitor
20e6 f
Predefine load output voltage
110 V and 60 Hz AC
Pulse width modulation technique
20e3 Hz
Table (2): important parameter of the proposed AVR

RESULT
The performance of the proposed AVR has been developed and simulated successfully. The controlling
REFERENCES

M. A. P. de Azpeitia, A. Fernandez, D. G. Lamar, M. Rodriguez, andM. M. Hernando, Simplified voltagesag filler for line interactive uninterruptiblepower supplies, IEEE Trans. Ind. Electron., vol. 55, no. 8,pp. 30553011, Aug. 2008.

J. D. Barros and J. F. Silva, Multilevel optimal predictive dynamic voltagerestorer, IEEE Trans. Ind. Electron., vol. 57, no. 8, pp. 27472760,Aug. 2010.

Y. W. Li, D. M. Vilathgamuwa, F. Blaabjerg, and P. C. Loh, A robustcontrol scheme for mediumvoltagelevel DVR implementation, IEEETrans. Ind. Electron., vol. 54, no. 4, pp. 22492261, Aug. 2007.

P. RonceroSanchez and E. Acha, Dynamic voltage restorer based onflying capacitor multilevel converters operated by repetitive control,IEEE Trans. Power Del., vol. 24, no. 2, pp. 951960, Apr. 2009.

K. H. Kwan, Y. C. Chu, and P. L. So, Modelbased H control of aunified power quality conditioner, IEEE Trans. Ind. Electron., vol. 56,no. 7, pp. 24932504, Jul. 2009.

Q. Wang and S. S. Choi, An energysaving series compensatio strategysubject to injected voltage and inputpower limits, IEEE Trans. PowerDel., vol. 23, no. 2, pp. 11211131, Apr. 2008.

P. Mitra, S. Chowdhury, S.P.Chowdhury, S.K. Pal, Y.H.Song and
G.A. Taylor PERFORMANCE OF A FUZZY LOGIC BASED AUTOMATIC VOLTAGE REGULATORIN SINGLE AND MULTIMACHINE ENVIRONMENT

JinnChang Wu, HurngLiahngJou,KuenDer Wu, and Shiue JungJanThreeArm AC Automatic Voltage Regulator IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 58, NO. 2, FEBRUARY 2011

N. Mohan, T. M. Undeland, and W. P. Robbins, Power Electronics Converters,Applications and Design, Media Enhanced Third Edition ed.New York: Wiley, 2003.

Z. J. Zhou, X. Zhang, P. Xu, and W. X. Shen, Singlephase uninterruptiblepower supply based on Zsource inverter, IEEE Trans. Ind. Electron.,vol. 55, no. 8, pp. 29973004, Aug. 2008.

C. C. Yeh and M. D. Manjrekar, A reconfigurable uninterruptible powersupply system for multiple power quality applications, IEEE Trans.Power Electron., vol. 22, no. 4, pp. 13611372, Jul. 2007.

C. B. Jacobina, T. M. Oliveira, and E. R. C. da Silva, Control ofthe singlephase threeleg ac/ac converter, IEEE Trans. Ind. Electron.,vol. 53, no. 2, pp. 467476, Apr. 2006.

M.H Rashid, Power Electronics ,circuits,devices and Applications, PHI Third Edition ed.New Delhi: 2008.

Ch. Krishna Rao & ,.Fuzzy logic controller based maximum power point tracking for PV System International Journal For Research & Development In Technology ,ISSN: 23493585; June, 2019, Volume 11, Issue 6

Ch. Krishna Rao A.Janakiram, G.Lalitha, G.Suneetha&G.Manikumar Transient Stability Analysis of a MultiMachine Power System with PSS and SVC International Journal of Scientific Development and Research (IJSDR) ,ISSN: 24552631; April 2019 IJSDR  Volume 4, Issue 4

Ch. Krishna Rao, K. Archana, L. Manikanta, K. Lalith kumar&K. Karunkumar Design And Implementation Of Iot Based Personal Health Monitoring System And Cardiac Arrest Locator International Journal of Research and Analytical Reviews (IJRAR) ,EISSN 23481269, P ISSN 23495138; March 2019,
Volume 6, Issue 1

K. Pooja, Ch. Krishna Rao & K. B. Madhu Sahu Power Quality Improvement in STATCOM Based PQcontroller For Grid connected to Wind Energy System Journal of Emerging Technologies and Innovative Research (JETIR) ,ISSN: 2349 5162; November 2018, Volume 5, Issue 11

G. Bharat Reddy, Ch. Krishna Rao , K. B. Madhu Sahu& K. B. Saikiran A Fuzzy based MCDPFC for Enhancement of Power Quality in Transmission Line International Journal of Pure and Applied Mathematics ,ISSN : ISSN: 13118080 (printed version); ISSN: 13143395 (online version),Volume 117 No. 21 2017, 231241

A. Bhaskara Rao, Ch. Krishna Rao , K. B. Madhu Sahu& K. B. Saikiran A Fuzzy Based Dvr For Mitigation Of Voltage Sag/Swell Problems Journal of Advanced Research in Dynamical and Control Systems (JARDCS) ISSN: 1943023X;
Vol. 6, Issue 14, 2017, ,pp.568580

P Sekhar, Ch. Krishna Rao , K. B. Madhu Sahu& T Jagan Mohan Rao Power Flow Control Performance Analysis Of A Fuzzy Logic Based Transformer Less UPFC Journal of Advanced Research in Dynamical and Control Systems (JARDCS) ISSN: 1943023X; Vol. 6, Issue 14, 2017, ,pp.11021112

B. Santhosh Kumar, Ch. Krishna Rao , K. B. Madhu Sahu& K.

Saikiran Enhancement Of Power Quality Using Fuzzy Controlled DStatcom In Distribution System International Journal of Electrical and Electronics Engineering Research (IJEEER)ISSN(P): 2250155X; ISSN(E): 2278943X Vol. 7, Issue 3, Jun 2017, 112 Â© TJPRC Pvt. Ltd.


D. Rama chadra Rao, Ch. Krishna Rao , K. B. Madhu Sahu& K.

Saikiran Enhancement Of Power Quality Using McDpfc In Transmission System International Journal of Electrical and Electronics Engineering Research (IJEEER) ISSN(P): 2250 155X; ISSN(E): 2278943X Vol. 6, Issue 6, Dec 2016, 112 Â© TJPRC Pvt. Ltd


G Durga Prasad, Ch. Krishna Rao , K. B. Madhu Sahu&K.Bhaskararao Performance of Fuzzy logic Based UPFC for Power flow Control International Journal of Electrical Engineering. ISSN 09742158 Volume 9, Number 3 (2016), pp. 329344 Â© International Research Publication House http://www.irphouse.com

B.Divya, Ch. Krishna Rao & K. B. Madhu Sahu Three Phase Grid Connected Transformer less Inverter for Photovoltaic with PMSM drive International Journal of Applied Engineering Research ISSN 09734562 Volume 11, Number 3(2016) pp. 20422048 Â© Research India Publications

P.Phalguna Rao, K. B. Madhu Sahu& Ch. Krishna Rao Performance Evaluation of High StepUp DCDC Converter Working Under Closed Loop Control Scheme International Journal of Applied Engineering Research ISSN 09734562 Volume 10, Number 15 (2015) pp. 3515335159 Â© Research India Publications

S.Rajendra prasad, K. B. Madhu Sahu& Ch. Krishna Rao Improvement of Power Quality by Current Controller for Grid Connected PV System International Journal of Applied Engineering Research ISSN 09734562 Volume 10, Number 14 (2015) pp. 3457234576 Â© Research India Publications

K.Srinivas Rao, K. B. Madhu Sahu& Ch. Krishna Rao A New Simplified Symmetrical Multilevel Inverter Topology With PV Applications International Journal of Applied Engineering Research ISSN 09734562 Volume 10, Number 12 (2015) pp. 3212532140 Â© Research India Publications

M. Naveena, K. B. Madhu Sahu& CH. Krishna Rao 16 Cell BackToBack Stacked Multicell Converter ISSN(P): 2250 155X; ISSN(E): 2278943X Vol. 5, Issue 1, Feb 2015, 3344

K. Dhilleswaramma, K. B. Madhu Sahu& CH. Krishna Rao Improved Power Quality Features Using Fuzzy Based Upqc Topology For Bldc Drive Applications ISSN(P): 2250155X;
ISSN(E): 2278943X Vol. 5, Issue 1, Feb 2015, 3558

P.Tulasi Rao , CH.Krishna Rao, K.B.MadhuSahu An Advanced Power electronics Interface For Photovoltaic Powered Induction motor based Electric vehicle ISSN 0976 6545(Print) ISSN 0976 6553(Online)Volume 5, Issue 12, December (2014), pp. 310320

CH Krishna Rao, K.B.MadhuSahu, I Ramesh,A.JagannadhamApplication of SSSC and IPFC for Stability Enhancement for SMIB and MMIB using FUZZY Logic Controller ISSN: 2321 919X, Vol 2, Issue 4 ,April, 2014

T Jagan Mohan Rao, P Anil Kumar, CH. Krishna Rao Voltage Source Inverter/Converter for the Improvement of Power Quality Using Fuzzy Logic Controller ISSN : 22489622, Vol. 4, Issue 5( Version 1), May 2014, pp.4650

G. Ashok, K. B. Madhu Sahu, CH. Krishna Rao,Closed Loop Operation of High Efficiency AcDc StepUp Converter Using Fuzzy Logic Controller, ISSN : 22489622, Vol. 3, Issue 6, Nov
Dec 2013, pp.10401047

U. Lilli Kumar, K. B. Madhu Sahu, CH. Krishna Rao,Fuzzy Controller Based Grid Connected Res At Distribution Level with Power Quality Improvement, Vol.2 – Issue 11 (November – 2013) eISSN: 22780181

T. Santosh Kumar, DR. K. B. Madhu Sahu, CH. Krishna Rao Total Harmonic Distortion Analysis of Three Phase Nonlinear Load Using HBridge Vsi Topology Based_ Dstatcom ISSN : 22489622, Vol. 4, Issue 1( Version 4), January 2014, pp.5662

CH.KrishnaRao,Dr.K B Madhu Sahu,Dr. Siva Yellampalli,B B Rao,Performance of a Fuzzy Logic Based AVR in SMIB, MMIB System and Power Flow Control Using SSSC and IPFC, IJERA, Vol. 2, IssueNo. 1, pp. 260268.