 Open Access
 Total Downloads : 14
 Authors : Amanpreet Kaur Sandhu , Dilsher Singh
 Paper ID : IJERTV7IS050301
 Volume & Issue : Volume 07, Issue 05 (May 2018)
 Published (First Online): 02062018
 ISSN (Online) : 22780181
 Publisher Name : IJERT
 License: This work is licensed under a Creative Commons Attribution 4.0 International License
Comparative Study of Perturb & Observe Method and Incremental Conductance Method for Maximum Power Point Tracking System
Er. Amanpreet Kaur Sandhu Electrical Engineering Deptt
CT Group of Institutions Shahpur Campus Jalandhar India
Er. Dilsher Singh Electrical Engineering Deptt
CT Group of Institiutions Shahpur Campus Jalandhar, India
Abstract Due to the mounting demand of electricity, inadequate reserve of fossil fuel and rising expenses of traditional sources, photovoltaic (PV) electricity turns into a promising substitute. It is a accepted potential of producing clean and renewable energy and due to this reason, the demand of PV technology structures will increase and there is a need to extract most electricity from them.So there is need of most strength point tracking (MPPT) in a PV system. It is a technique that can operate photo voltaic PV structures in such a way that they produce most electricity that can be generated. MPPT tracking machine works based on a tracking algorithm which is furnished through a manipulate system. In this dissertation, a contrast is made between perturb and look at MPPT method and incremental conductance MPPT approach to make clear understanding about their conduct for monitoring maximum electricity factor (MPPT) of PV module. For this purpose, a simple and correct model of photovoltaic module is proposed and simulated. The mathematical model and MPPT with H BRIDGE two are mentioned with MATLAB/Simulink and analyze the distinction between P&O and InC approach.
Keywords MPPT Maximum Power Point Tracking; H Bridge; perturb and observation (P&O), Incremental conductance (InC)
INTRODUCTION
In the power part the request of vitality isn't sufficient to satisfy the everyday necessity this need of vitality offer ascent to utilization of customary vitality asset. Used along the side with regular frameworks to take care of the vitality demand. The Mathematical Model of Simple PV System.
Fig 1 demonstrates the single diode model of the PV cell that is properly built with a parallel current source to the diode, a shunt resistor Rp, an arrangement resistor Rs and a heap resistor RL. The fundamental conditions [2,3] from the hypothesis of semiconductors that numerically depicts the IV qualities of the perfect photovoltaic are given as takes after.
I = Iph – ID
Where
ID = Iexp ((qV/akT)1) (2)
I = Iph – I exp ((qV/akT)1) (3)
In the above conditions, Iph speaks to the current produced by the episode light, ID is the diode current and Io is the invert immersion current of the diode, q is the electrical charge, k is the Boltzmann steady, T is the temperature of the pn intersection, and 'a' is the diode ideality factor (consistent).
The expression for the photovoltaic current is given by:
I = Iph – I[ exp ( V + IRs / VT) – 1 ] ( V + IRs / Rp ) (4)
And expression for voltage is given by
V = IphRp – IRp + I[ exp ( V + IRs / VT) – 1 ] IRs (5)
MPPT TECHNIQUES

Perturbation and Observation Method
The Perturbation and Observation Method (P&O) is one of the most famous MPPT techniques due to the fact of its simplicity. The P&O technique operates with the aid of making small incremental changes in voltage and measuring the resulting trade in power. Two by comparing the modern day power measurement to the previous energy measurement, the P&O technique selects the direction for the subsequent perturbation. The path the subsequent perturbation will take is described in table
Perturbation
Change in Power
Next Perturbation
Positive
Positive
Positive
Positive
Negative
Negative
Negative
Positive
Negative
Negative
Negative
Positive
Table 1: Table of operation for the P&O MPPT method.
Furthermore, P&O strategies can fail under rapidly altering atmospheric stipulations (see Fig. 2). Starting from an operating factor A, if atmospheric prerequisites remain approximately constant, a perturbation V the voltage V will bring the working factor to B and the perturbation will be reversed due to a decrease in power. However, if the irradiance will increase and shifts the electricity curve from P1 to P2 within one sampling period, the running factor will go from A to C. This represents an extend in power and the perturbation is kept the same. Consequently, the running point diverges from the MPP and will hold diverging if the irradiance step by step increases
Fig 2. Divergence of P&O from MPP
Fig 3. Flow diagram of P&O method
ADVANTAGES

Reliable result.

It is not dependent on the panel properties and on characteristics.
DISADVANTAGES

The accuracy of the system and its time requirement are depending on the size of perturbation.

The P&O method is not suited in fast changing environmental conditions.

At the steady state condition the output voltage and current signals of PV panel oscillates which causes losses.


Incremental Conductance Method:
The theory at the back of the incremental conductance method (IC) is to determine the terminal voltage of the PV module with the aid of measuring and comparing the incremental and instantaneous conductance of the PV module. If it is located that the incremental conductance is equal to the instant conductance, it shows that the maximum electricity factor is found. It has been found that within operating limits, output power will increase with growing terminal voltage of the PV module (slope of the energy curve is positive, dP/dV>0). On the contrary, at working factors previous MPP there is a decrease in the output power with an increase in terminal voltage of the PV modules (the slope of the energy curve is negative, dP/dV<0). When the working factor is exactly at the MPP, the slope of the curve as anticipated is zero. These observations are graphically represented in below Fig 4
Fig 4. A schematic representation of the power curve and the slope at the maximum power point.
From the flow design it can be determined that if dV=0 however dI>0, the photo voltaic irradiance has extended and voltage at the most electricity factor rises. Thus, the operating voltage of the PV module has to be multiplied in order to tune the maximum power point. On the other side, if the solar irradiation decreases, voltage at the maximum energy factor falls. The operating voltage at this point desires to be decreased
Fig. 5 The flow diagram of incremental conductance method

ADVANTAGES

Good yield under rapidly changing atmospheric condition.

DISADVANTAGES

Efficiency is somewhat less then P&O method

Requires complex and costly control circuit.

Needs four sensors to accomplish its MPPT action.

Output voltage and current signals of PV panel oscillates even at steady state.

The Proposed Model:
In the proposed model the PV array consists of 86 parallel strings. Each string has 7 SunPower SPR415E solar cell two modules related in series. The converter is modeled the usage of a 3level IGBT bridge with PWMcontrol. The inverter choke RL and a small harmonics filter C are used to filter the harmonics generated by using theIGBT bridge. A 250kVA 250V/25kV threephase transformer is used to join the inverter to the utility distribution system. The Maximum Power Point Tracking (MPPT) controller is based on the 'Perturb and Observe' technique. This MPPT system mechanically varies the VDC reference signal of the inverter VDC regulator in order to gain a DC voltage which will extract maximum energy from the PV array.
Fig 5 Proposed Array Model
Fig 6. IV &PV Curves of Pv Array
Fig 7. PV Characteristics of Pv Module
Fig 8 P&O model in Mat lab/Simulink
Fig 9 Voltage and current waveforms without MPPT techniques.( DC Parameters)
Fig 10 Voltage and current waveforms with MPPT techniques (DC Parameters) with P&O algorithm
Fig 11 Incremental conductance model in Matlab/Simulink
S.No 
Time 
Technique 
Voc 
Pdc 
Isc 
1 
1 sec 
P&O 
481 
244 
0.51 
2 
1.5sec 
P&O 
475 
52 
0.11 
3 
1 sec 
IC 
481 
248 
0.52 
4 
1.5sec 
IC 
478 
52 
0.11 
Fig 12 Voltage and current waveforms with MPPT techniques (DC Parameters) with InC method
Table 2: Comparison of P&O and IC methods CONCLUSION
MPPT methods plays very essential position while designing PV array module/system .Without MPPT strategies there located much fluctuations and low effectivity in energy output however with MPPT methods expanded efficiency and energy output has been obtained. The P & O and InC MPPT algorithms are simulated and in contrast using the equal conditions. When atmospheric stipulations are regular or change slowly, the P&O MPPT oscillates close to MPP however InC finds the MPP precisely at changing atmospheric conditions also.
. It is proved that Incremental conductance technique has higher performance than P&O algorithm
REFERENCES

J. Clerk Maxwell, A Treatise on Electricity and Magnetism, 3rd ed., vol. 2. Oxford: Clarendon, 1892, pp.6873.

I.S. Jacobs and C.P. Bean, Fine particles, thin films and exchange anisotropy, in Magnetism, vol. III, G.T. Rado and H. Suhl, Eds. New York: Academic, 1963, pp. 271 350.

K. Elissa, Title of paper if known, unpublished.

R. Nicole, Title of paper with only first word capitalized,
J. Name Stand. Abbrev., in press.

Y. Yorozu, M. Hirano, K. Oka, and Y. Tagawa, Electron spectroscopy studies on magnetooptical media and plastic substrate interface,

IEEE Transl. J. Magn. Japan, vol. 2, pp. 740741, August 1987 [Digests 9th Annual Conf. Magnetics Japan, p. 301, 1982].

Radhakrishnan, N. and Ramaswamy, M. Fuzzy controlled fly Back converter for solar energy system, , March,2014 pp. 588591

Kumaresh.V, MridulMalhotra, Literature Review on Solar MPPT Systems, Number 3 (2014), pp. 285296

Maninder Pal Singh, Akhil Gupta, A NeuroFuzzy Approach to Grid connected MultiJunction PV Array using PWM Inverter , 2016,

TrishanEsram, Comparison of Photovoltaic Array Maximum Power Point Tracking Techniques ,june 2017.

J. Suryakumari, G. Sahiti, G. Sudhakar ,Analysis and Simulation Of Perturb and Observe Mppt Technique, Aug 2013, pp.16621668

M. Young, The Technical Writers Handbook. Mill Valley, CA: University.

Azad Ghaffaria,n, Sridhar Seshagirib,Multivariable maximum power point tracking for photovoltaic micro converters using extremum seeking ,2015, pp.8193.

W. Xiao and W. G. Dunford, A modied adaptive hill climbing MPPT methodforphotovoltaicpowersystems,. IEEE Power Electron. Spec. Conf., 2004, pp. 19571963.

S. Manobalan, R.Anandaraj, . Harmonic Reduction of Cascaded HBridge Inverters with Photo VOLTIC By Considering DC Voltage Ratios and Device Loss IEEE Transl april 2015.

Y. Yorozu, M. Hirano, K. Oka, and Y. Tagawa, Electron spectroscopy studies on magnetooptical media and plastic substrate interface, IEEE Transl. J. Magn. Japan, vol. 2, pp. 740741, August 1987 [Digests 9th Annual Conf. Magnetics Japan, p. 301, 1982].

Mohammed A. Elgendy , Operating Characteristics of the P&O Algorithm at High Perturbation Frequencies for Standalone PV Systems . IEEE Transaction of energy consevation, VOL. 30, NO. 1, marcp015,pp. 189197.

Azad Ghaffaria,n, Sridhar Seshagirib, Multivariable maximum power point tracking for photovoltaic micro converters using extremum seeking ,2015, pp.8193.

Mukesh Kr. Gupta and Rohit Jain, Design and Simulation of Photovoltaic Cell Using Decrement Resistance Algorithm, Indian Journal of Science and Technology ,may 2013.

Hussein K H, Muta I et al. (2005). Maximum photovoltaic power tracking: an algorithm for rapidly changing atmospheric conditions, IEE Proceedings Generation, Transmission and Distribution, vol 142, 953959.

Liu F, Duan S et al. (2008). A variable step size INC MPTT method for PV system, IEEE Transactions on Industrial Electronics, vol 55(7), 26222628.