investigation of high voltage gain dc-dc converter … · 2018. 10. 8. · renewable energy and to...

INVESTIGATION OF HIGHVOLTAGE GAIN DC-DC

CONVERTER USING PASSIVECLAMP NETWORK FOR

RENEWABLE ENEGY SOURCES

Mr.Arockiaraj. S1, Dr.B.V.Manikandan2

Mr.B.Sakthisudhursun31,2,3Mepco Schlenk Engineering college,

Sivakasi.

August 4, 2018

Abstract

The demand of renewable energynow a days as an elec-trical source is increased due to the amount of fossil fuel thatbecomes more limited. This paper presents modeling andsimulation of proposed boost converter for maximum powerpoint tracking (MPPT) of a standalone PV system undervarying atmospheric conditions. The system composed of aPV module, proposed converter and a DC load. The highgain boost converter is used to step up the input voltage andto minimize the switching losses. This topology raises theefficiency of the DC-DC converter for PV Power Condition-ing Systems (PVPCS). A single switch boost converter isproposed and the converter is connected in parallel througha switching inductor which is used to obtain a switchingoperation. It has better performance characteristics whencompared to conventional converters due to its increasedefficiency, reduction in weight and greater reliability. Maxi-mum Power Point Tracking (MPPT) control techniques are

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International Journal of Pure and Applied MathematicsVolume 120 No. 6 2018, 10983-10999ISSN: 1314-3395 (on-line version)url: http://www.acadpubl.eu/hub/Special Issue http://www.acadpubl.eu/hub/

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used in Photo Voltaic (PV) systems to maximize the re-sulting revenue of the PV panel output power by track-ing MPP continuously. In this project P&O (Perturb Ob-serve) and IIC (Improved Incremental Conductance) meth-ods of Maximum Power Point Tracking (MPPT) controltechniques have been proposed and simulated using PowerSimulation (PSIM) environment. The simulation result re-veals that the Improved Incremental Conductance methodtracks more maximum power than other MPPT techniques.

1 Introduction

The evolution of high power electronic devices was started withmercury-arc values. But mercury-arc rectifiers were a part of in-dustrial electronics and hence its scope for applications was limited.Today many researches are under progress to increase the utility ofrenewable energy and to reduce the power consumption. Renewableenergy forms are hydro, wind, tidal, solar and geo thermal energy.Many renewable energy technologies today are well developed, reli-able, and cost competitive with conventional generators. The costof renewable energy technologies is on falling trend and is expectedto fall further as demand and production increases. Power elec-tronics find applications in most Renewable Energy Source (RES)technologies, solar energy systems being the most important appli-cations. Sun is the natural source of light energy and is essentialfor living things to sustain their life on earth. The Photo Voltaic(PV) system will utilize the solar energy as the power source andtransfer the power into battery through conditioning by power elec-tronics, after that the energy is stored in a battery then convertedby another stage of power electronics to use in a home load. Thework carried out in this paper has been summarized in five sections.In section-1, the study begins with an introduction to this paper;it gives information about objective and the main outcome of thepaper. Section-2, handles the importance of power electronics (DC-DC converter) to be capable to design mathematically a suitablevalue of its parameters to work in the best conditions. In section -3,the study describes the hierarchy of PV system and the P-V & I-Vcharacteristics of PV array. Section-4, illustrates the importanceof using MPPT technologies in PV systems and explains the two

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main types of MPPT. Section -5 deals with simulation results ofconverter with PV array in Psim. Finally, chapter Section -6 dealswith hardware implementation of the proposed system.

2 OBJECTIVE

The basic objective would be to develop a high gain boost converterfor PV system and operate the PV systems at its MPP. The pro-posed converter and the solar panel are simulated in Psim. Thenovel high gain boost converter is proposed in this project. Theconverter reduces the switching loss thereby it increases the con-version efficiency of the converter and cost of the converter alsoget reduced. Then the MPPT algorithms were simulated in logi-cal form using Psim. The MPPT algorithms include Perturb andObserve method, Improved Incremental Conductance method, toobtain the maximum power point operation of PV array during allenvironment conditions. Finally, the PV array is interfaced withproposed converter for extracting of maximum power with highgain ratio by Improved Incremental Conductance method.

Figure1. Block Diagram of the Project

The figure 1.1 comprises of PV module, proposed converter, con-trolled and constant DC load. The solar panel voltage and currentdepends on the temperature and solar insulation. In order to ex-tract maximum power from the solar panel in all environmentalconditions MPPT techniques has been used.

3 DESIGN OF PROPOSED CONVERTER

The parameters of the proposed converter were designed accordingto the analysis above on the operation of the proposed converter.The power equation is

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Where,Vout - Output VoltageVs Source VoltageL1, L2 - Coupled InductorsM Mutual InductanceR Load ResistanceT- Switching PeriodD Duty CycleA. DESIGN PARAMETERS OF THE PROPOSED CON-VERTERThe design parameters of the proposed converter are shown in table1.1

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Table 1. Design Parameters of the Proposed Converter

B. DESIGN SPECIFICATIONS OF THE PROPOSED CON-VERTERThe design specifications of the proposed converter are shown intable 1.2

Table 2. Design Specification of the Proposed Converter

C. SIMULATION CIRCUIT OF PROPOSED CONVERTERThe simulation circuit for proposed converter is shown in the figure2.8 The simulation is done using Psim software.

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Figure 2. Circuit Diagram of the Proposed Converter

D. SIMULATION RESPONSE OF INPUT VOLTAGEWAVE-FORM

Figure 3. Input Voltage Response of the Converter

E. SIMULATION RESPONSE OF OUTPUT VOLTAGEWAVEFORMThe simulation response of the output voltage is shown in the figure2.10

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Figure 4. Output Voltage Response of the Converter

4 ANALYSIS OF PROPOSED CON-

VERTER

The table 4.1 shows the analysis of the proposed converter for differ-ent input voltage and current values by the calculation of efficiencyfor Duty cycle of 0.8.

Table 4.1 Analysis of Proposed Converter

A. SOLAR CELL MODELING

Figure 5. Equivalent Circuits of Solar Cell

Applying node equation in figure 3.9, where IPH, diodes, RseandRsh are meeting together.

Iph = ID + ISH + I

I = Ipv − ID − ISE

I = IPH −Is[e

(q(V + IRSE

kT

)− 1

]−Is

[e

(q(V + IRSE)

2KT

)− 1

]−(V +I∗RSE

RSH)

When both diodes are combined together then equation is become

I = IPH − Isat[exp

(q(V + IRSE

AkT

)− 1

]−

(V + I ∗ RSE

RSH

)

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Where A is ideality factor and takes the value between 1 and 2B.FLOWCHART FOR PERTURB AND OBSERVE (P &O)ALGORITHM

Fig 6.Design of P & O Algorithm by Psim

Fig 7. Flowchart of P & O Algorithm

C. IMPROVED INCREMENTAL CONDUCTANCEThe IIC MPPT method is based on the value of derivative of cur-rent over voltage. It is zero at MPP, positive on the left of the

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MPP, and the negative on the right. The MPP can be tracked bycomparing the instantaneous conductance (I/V) to the incrementalconductance. Based on that voltage reference (Vref) is increased ordecreased with small value at which the PV array is forced to oper-ate. Under the variations in atmospheric condition this algorithmtracks the MPP by applying increments or decrements to Vref. Theeffective way to utilize IC is to have prior knowledge of Vref value.This will reduce the tracking time of the algorithm. For that wecan make use of any other model-based MPPT method in associa-tion with this algorithm. Under uniform irradiation conditions, thesimplest open circuit voltage method is used to find Vref, whichuses the linear relationship between the open circuit voltage andmaximum power point voltage. The equation can be written asVref = KVocHere Voc, is the open circuit voltage and K is a constant whichdepends on PV cell characteristics, which ranges from 0.73 to 0.80.

Figure 8. Design of IIC Algorithm by Psim

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Figure 9. Flowchart of IIC Algorithm

5 SIMULATION RESULT OF PV SYS-

TEM

The PV module has been mathematically modelled for irradiationof 1000W/m2 and temperature of 250◦ C. The simulation result forstandard condition is shown in figure 5.1.

Figure 10. Simulation result for standard condition

A.SOLAR MODULE SPECIFICATIONThe solar module specification is given in table 5.1.

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Table 5.1 Solar module specification

B. PSIM SIMULATION CIRCUIT USING P & OThe open loop system with MPPT controller Simulink diagram ofthe PV module interfaced with the converter with P & O as shownin figure 5.3.

Figure 11. Simulation Circuit of P & O Method

C. SIMULATION RESPONSE OF P & O METHODThe simulation output of converter with MPPT at standard irradi-ation and temperature condition is shown in figure 5.4. The outputvoltage from the PV module is about 12.14. A pulse of duty cycle0.833 is produced as a result of P & O and the output of the con-verter when P & O is used as an MPPT algorithm is about 362.20Vand shown in figure 5.3.D. SIMULATION RESPONSE OF INPUT VOLTAGEWAVE-FORMThe simulation response of input voltage waveform is shown is fig-ure

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Figure 12 Simulation of input response of P & O method

E.SIMULATION RESPONSE OF OUTPUT VOLTAGEWAVEFORMThe simulation response of output voltage waveform is shown isfigure 5.4.

Figure 13 Simulation of Output Response of P & O Method

6 HARDWARE IMPLEMENTATION

Fig 14 Hardware Implementation of Proposed System

The hardware implementation of the block diagram is shown in fig-ure 6.1. The output of the solar panel is given to DC-DC converter.It boosts up the voltage and the DC output voltage is given to theload.

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A.HIGH GAIN BOOST CONVERTERHardware Circuit for PWM Generation

Figure 15. Hardware Circuit for Pulse Generation UsingPIC16F877A

Figure 6.4 shows the hardware circuit for PWM generation. Thepulses are generated at the frequency of 20 KHz. A potentiometeris used to adjust the duty cycle. The driver IC L7805 increases theamplitude of the pulses to 18.8V and makes it sufficient to drivethe MOSFET.

Figure 16. Pulse Generation Waveform Using PIC18F877A

Figure 6.5 shows the hardware output of the PWM generation cir-cuit. These pulses are given as gating signals for the switches ofthe High Gain Boost Converter.B.HARDWARE CIRCUIT OF HIGHGAIN BOOST CON-VERTER

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Figure 17. Hardware Circuit of High Gain Boost Converter

Figure 6.6 shows the hardware circuit of High Gain Boost Con-verter. IRF870 is used as the switch. The switch is triggered at afrequency of 20 KHz. A resistor of 360 is used as the load. Theoutput of the converter for an 80% duty cycle is shown in figure6.6. For a DC voltage of 12V, 366.6V DC voltage is obtained asoutput.

7 CONCLUSION

This project presents a simple and efficient photovoltaic power gen-eration system. It models each component and simulates the systemusing Psim software. The result shows that the PV model using theequivalent circuit in moderate complexity provides good matchingwith the real PV panel. Simulations perform comparative tests fortwo MPPT algorithms with using High Gain Boost Converter afterthat design and simulate a full system standalone PV system toproduce DC voltage for an industrial load. The main drawbacks ofthe P & O technique are its poor dynamic response and swingingaround the maximum power point during steady state operation.From the simulation results it is observed that an IIC approachprovides higher percentage of maximum power with less responsetime than P & O method. Further it can be connected with gridsystem through proper power converter circuit for meeting out thepower demands. The MPPT techniques were implemented with thePsim real-time control in this project and the same concept may beextended with the Microprocessor or DSP and also integrated withthe voltage controller in the future.

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References

[1] Moumita Das, VivekAgarwal(May 2016)Design and Analysisof a High-Efficiency DCDC Converter with Soft Switching Ca-pability for Renewable Energy Applications Requiring HighVoltage Gain, IEEE Transactions on Industrial Electronics,vol. 63, no. 5.

[2] Kuj-Jun Lee, Byoung-Gun Park, Rae-Young Kim, and Dong-Seok Hyun (April 2015) A boost converter with capacitor mul-tiplier and coupled inductor for AC module applications, IEEETransactions on Power Electronics vol. 27, no.4.

[3] Preti Tyagi1, Kotak V.C. Sunder Singh V.P. Design HighGain DC-DC Boost Converter with Coupled Inductor, in In-ternational Journal of Research in Engineering and TechnologyeISSN: 2319-1163 pISSN: 2321-7308.

[4] Mohamed O. Badawy, AhmetYilmazSozer, and Iqbal Husain(March/April 2014) Parallel Power Processing Topology forSolar PV Applications, IEEE transactions on industry appli-cations, vol. 50, no.2.

[5] Felinto S. F. Silva, Antnio A. A Freitas, SrgioDaher, Saulo C.Ximenes, Sarah K. A. Sousa,Edilson M. S. , Fernando L. M.Antunes, Ccero M. T. Cruz (2009) A Novel Maximum PowerPoint Tracking Technique for Photovoltaic Module Based onPower Plane Analysis of I-V Characteristics, 978-1-4244-3370-4/09/$25.00 2009 IEEE 486.

[6] Mohammed A. Elgendy, Bashar Zahawi, and David J.atkinson(Jan 2013) Assessment of the Improved Incremental Conduc-tance Maximum Power Point Tracking Algorithm, IEEE trans-actions on Sustainable Energy., vol. 4 no. 1, pp. 108-117.

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[8] Fan Zhang, KaryThanapalan, Andrew Procter, Stephen Carr,and Jon Maddy (June 2016) Adaptive Hybrid Maximum Power

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Point Tracking Method for a Photovoltaic System, IEEE trans-actions on Energy Conversion., vol. 28, no. 2, pp.353-360.

[9] Falah Al Hassan, Vladimir L. Lanin (September 2012) LosslessDCDC Boost Converter with High Voltage Gain for PV Tech-nology, Asian Transactions on Engineering (ATE ISSN: 2221 -4267) Volume 02 Issue 04.

[10] Theodore Soong, Peter Lehn (2012) A Transformerless HighBoost DC-DC Converter for use in Medium / High VoltageApplications, University of Toronto, 10 King’s College Rd.,Toronto, IEEE.

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investigation of high voltage gain dc-dc converter … · 2018. 10. 8. · renewable energy and to...

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