International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 9- May 2015
Simulation and Analysis of Soft Switch Converter
with Adaptive MPPT of PV System
1
amrit Pal Singh, 2s Bhanu Prakash
1
mtech Student 2 Assistant Professor
Department Of Electrical Engineering
Dit University Mussoorie Diversion Road, Dehradun, Uttarakhand,India
Abstract – The primary aim of the present work is to assess
the performance of photovoltaic panel using the maximum
power point tracking (MPPT). To establish the superiority of
the MPP in PVpanel operation. A comparative operation of
MPPT is done. The comparative study of the performance of
converter DC-DC Boost converter is quantitatively expressed
in terms of different indices. The adaptive MPPT technique
has been deeply studied. This greatly simplifies the
implementation of Soft Switch converter (DC-DC Boost
converter) with MPPT technique without compromising the
accuracy issue. Satisfactory MPP for PV panel is performed
using DC-DC Boost converter (Soft Switch Converter). All the
study has been made in MATLAB/SIMULINK environment.
II.
PV CELL
A photovoltaic cell is a semiconductor gadget whose p-n
intersections are presented to daylight. It is comprised of a
few distinct sorts of semiconductor gadgets. Si PV cells are
for the most part utilized in light of the fact that they are the
stand out whose creation is monetarily possible in huge
scale. Fig 1 delineates the physical structure of a PV cell.
PHOTONS
Keywords— soft switch converter, MPPT, PV, dc-dc boost
converter
+
N-LAYER
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I.
INTRODUCTION
In last few years, global warming have become important
issue on international agenda. Green houses gas emission;
demanding to be reduced by developed countries. The
production of energy based on fossil full is declining
therefore clean energy source production is increasing for
future development. As requirement and need of energy is
increasing around the world. Important issue is growing an
alternative energy resource.
Standalone PV systems are used to provide electricity to
the isolated users or loads remote as of the electricity grid
and hard to feed as of poorly accessible areas. In this
technique it is compulsory to store energy produced by PV
system with battery to feed the load at night or when sun is
not present.
Grid connected PV system are parallel connected to public
grid and design to input energy produced into same as
becoming power plant. They are used to condense the
energy requirements of building for public use.
The PV module gives the output directly proportional to
the irradiance and temperature by using photoelectric
effect. If there is partial shading on array then that is
tracked and studied my MPPT block using technique to
extract the MPP.
ISSN: 2231-5381
-
P-LAYER
Fig 1. Physical structure of solar cell
PV cell chips away at the rule of photoelectric impact. At
the point when daylight hits the surface of the matter,
electrons gets catapulted from the conduction band and
some bit of the sun oriented energy is consumed by the
semiconductor. The electrons from the valence band hops
to the conduction band when the energy of the photons is
more noteworthy than the band crevice vitality of the PV
cell. Photons with energy not exactly the band gap energy
are pointless and create no current and voltage.
Photons energy more prominent than the band hole energy
are utilized to produce power. These electron gap sets are
made in the district of the semiconductor. These electrons
are allowed to move in the heading by the activity of the
electric field introduce in the PV cells. These electrons
embody current and can be utilized for outside utilization.
These voltage and current produces indebted force
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International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 9- May 2015
III.
EQUIVALENT CIRCUIT OF SOLAR CELL
The electrical model of solar cell can be represented in the
Fig 2:
Rs
D
v
Rsh
IV.
SOFT SWITCH CONVERTER
In power electronics “soft-switching” term refer to different
techniques where switching transitions are made more
gradual in order to force voltage or current to be zero and
hence the switching transition is done. Using soft-switching
EMI can be reduced because on to off and off to on
switching transitions are gradual i.e. they are not sudden.
Switching losses can be reduced as dissipated power from a
switch are made proportional to the overlapping of voltage
and current across switch. switching transition time, soft
switching force i.e voltage or current are made to be zero
such that there is no overlapping of current and voltage and
hence switching loss is zero.
SOFT SWITCHING TYPES:
Fig – 2 Equivalent circuit of a solar cell
(i)
ZVS (zero voltage switching)
(ii)
ZCS (zero current switching)
The voltage-current equation is expressed as:
I = IL – ID ( e
-1 ) –
[1]
Where I is output current, Vis the O/P voltage, Io is the
dark saturation current, q is charge of an electron, A is
diode quality (idealistic) factor, K is Boltzmann constant, T
is absolute Temperature, Rs is series resistance, Rsh is shunt
resistance of the solar cell, Rs represent existing by contact
and bulk semiconductor material of solar cell. Origin of Rsh
is difficult to explain (related to non ideal nature of p-n
junction). In ideal case: Rs would be zero & Rsh would be
infinity.
However ideal situation is not possible or manufactured the
performance of semiconductor can be improved by
minimizing the effect of resistance. As to simplify the
model [10] effect of shunt resistance is not considered and
neglected.
A PV panel is collected of many solar cells. In PV panel
the solar cells are connected in series and parallel so as to
get the required output current and voltage of PV panel &
high enough to fulfil the requirement of the
equipment.Taking into consideration the simplification
model of solar cell as shown in Fig – 3.2.
I = nPIL – nPID ( e
D
Fig – 3 ZVS MOSFET IMPLEMENTATION
L
Cds
D
-1 )
Fig- 4 ZCS IGBT IMPLEMENTATION
np & ns are number of solar cell in parallel & series
respectively.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 9- May 2015
Switching loss of MOSFET or IGBT can be reduced by
both ZCS and ZVS. For MOSFET ZVS is preferred and for
IGBT ZCS is preferred. In MOSFET losses due to
discharging of Cds can be reduced by ZVS, when it is
turned on whereas cannot be reduced by ZCS.
Two most general types of DC-DC converters are
therefore in this modules cannot be physically moved in
order to point modules directly to the sun, as mechanical
tracking system cannot be implemented on MPPT. In
MPPT the electrical operating points of the modules are
varied such that modules produces maximum available
power.
Buck converter (O/P voltage is stepped down)
Conventional controller at 12 V
Extract 53 W
PV Amps
Boost converter (O/P voltage is stepped up)
Some other DC-DC converters are CUK , Buck-Boost,
ZETA and Epic etc.
The circuit diagram of boost converter is as shown in fig1.3 and ideal waveforms are as shown in fig-4.
During steady state condition, after turning ON switch the
whole I/P voltage will be applied across L m . Input inductor
and Lm will store energy when switches will be turned OFF.
A negative voltage (Vm -Vo) will be applied across inductor
and output capacitance C0 will receive the energy stored in
inductor. During steady-state O/P voltage of boost inductor
should always be greater than I/P voltage as ratio of O/P
voltage to I/P voltage isL
Id
D
Vo
Solar boost MPPT controller
Operate module at its max. Power
Voltage extract 75 W
PV volts
Fig 6 – Operation of MPPT
From solar array MPPT algorithm is required to obtain
maximum power as MPP varies with temperature and
irradiation.
DC-DC
Temp.
C
DC
SOLAR
PANEL
R
Is
DC
CONVERTER
INVERTER
LOAD
Irradiation
Fig - 5 DC-DC BOOST CONVERTER
MPPT
By applying periodic pulse (Vge) between gate (G) and
emitter (E) of the device, switch can be operated in a boost
converter. When pulse Vge is high, MOSFET is ON and
when pulse will be low, MOSFET will be OFF. AS ,duty
cycle of converter, hence the ratio of O/P and I/P voltage
will be determined by the width of pulse V ge , such that it is
the pulse width which will ultimately control and regulate
the O/P voltage.
Fig 7– Block Diagram
TECHNIQUES OF MPPT
Hill - Climbing method, Perturb and Observe, Incremental
conductance
V.
MPPT
Perturb and Observe
MPPT is an electronic system in which PV module is
operated in a manner that produce all the power module
which is capable of. As known, MPPT is electronic system
ISSN: 2231-5381
In perturb & observe, sign which decide what the next
perturbation should be is decided by sign of the last
increment in power & of the last perturbation.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 9- May 2015
As shown in Fig. – 7 on the left side of MPP increment in
the voltage will increase the power but on the right side as
the voltage decreases, power will increase.
MPPT signal is generated by a MPPT model by adaptive
MPPT technique.
MPP
ISC
VOC
voltage
FIG – 8 GRAPH FOR PERTURB AND OBSERVE
Perturbation are kept in the same direction, with the
increase in power & perturbations will be in opposite
direction if power will decrease. Algorithm here will be
implemented depending on the above facts.
Fig 10. Result waveform –output voltage, current and input voltage
Until MPP is reached process will be repeated. Around
MPP, the Operating points will keep Oscillating. This
problem is so common in Inconductance method.
VI.
SIMULATION AND RESULTS
Fig – 11.Comparison of result with reference [1 ] graph
Fig 9. Simulation model
Fig – 12 IGBT voltage and current
In proposed system simulation is done using a DC-DC
boost converter (Soft switch converter) for DC-DC
conversion the IGBT gate is fed by MPPT signal. The
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International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 9- May 2015
N. Femia et al. “ Optimization of perturb and observe
maximum power point tracking method” IEEE
Transactions on Power Electronics, VOL.20 no 4 , PP. 963973 , JULY 2005.
D. Sera et al. “ Improved MPPT method for rapidly
changing environmental condition” in Proc. IEEE
International symposium on Industrial Electronics , 2006 ,
VOL.2 , PP. 1420-1425.
Fig – 13 Solar panel output without control
VII.
CONCLUSION
Adaptive MPPT scheme for converter is implemented
using PWM gate signal which is used to generate gate
signal from adaptive MPPT for the DC-DC boost
converter. In this MPP is achieved by using adaptive MPPT
technique. The converter is fed by a PV array and the gate
signal fed to IGBT of converter by signal generated by
adaptive MPPT. The proposed system has results which are
improved and shows less fluctuation or distortion.
VIII.
REFERENCES
C.Zang et al. “ A modified MPPT method with variable
perturbation step for photovoltaic system” in power
electronics and motion control conference , 2009 , pp.
2096-2099.
L Piegari R. Rizzo “ Adaptive perturb and observe
algorithm for photovoltaic maximum power point tracking”
renewable power generation , IET VOL.4 no 4.PP. 317-328
, JULY 2010.
ISSN: 2231-5381
T. Esram et al. “ Comparison of photovoltaic array
maximum power point tracking techniques” IEE
transactions Energy conversion, VOL.22 no.2, PP. 439-449
, JUNE 2007.
Tekeshwar prashad sahu et al[1]. “simulation and analysis
of perturb & observe MPPT algorithm for PV array using
CUK Converter.” Advance in Electronics and electric
engineering. ISSN 2231-1297, Volume 4, no. 2 (2004) ,
pp.213-224.
Rajesh.K, Kailash Krishna Prasad.B"Hardware Realization
of Single Axis Solar Tracking System by Using a Cost
Effective Microcontroller", International Journal of
Engineering Trends and Technology (IJETT), V23(7),326328 May 2015. ISSN:2231-5381
Biren Gevaria and Khushbu Shah, ―Simulation and
Prototyping of Microcontroller Based Maximum Power
Point Tracking of PV Array, International Journal of
Engineering Trends and Technology (IJETT) – Volume 21
Number 7 – March 2015.
Kailash Krishna Prasad.B"Analysis and Design of
Distributed MPPT System Suitable for Non-Uniform Solar
Irradiation", International Journal of Engineering Trends
and Technology (IJETT), V22(9),432-437 April 2015.
ISSN:2231-5381
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