30-06-2012, 01:42 PM
Perturb and Observe MPPT Algorithm for Solar PV Systems-Modeling and Simulation
[attachment=26285]
Abstract
The following paper validates an algorithm for
Maximum Power Point Tracking using Perturb and Observe
technique. The algorithm starts by setting the computed
maximum power PMAX to an initial value (usually zero).
Next the actual PV voltage and current are measured at
specific intervals and the instantaneous value of PV power,
PACT is computed. PMAX and PACT are compared.
PMAX and PACT are compared. If PACT is greater than
PMAX, it is set as the new value of PMAX. At every instant
the PACT is calculated, and the comparison is continuously
executed.
INTRODUCTION
As people are concerned with the fossil fuel exhaustion
and the environmental problems caused by the
conventional power generation schemes present,
renewable energy sources, photovoltaic panels and windgenerators,
to mention a few are now in great need [2].
Among several renewable energy sources, photovoltaic
arrays are used in many applications such as water
pumping, battery charging, hybrid vehicles, and grid
connected PV systems. The principal advantages
associated with photovoltaic arrays are that it consists of
no moving parts. Do not produce any noise and
maintenance costs are minimal. It is also a clean source of
energy. Amount of energy produced by the sun is so large.
P&O MPPT TECHNIQUE
The problem considered by MPPT methods is to
automatically find the voltage VMPP or current IMPP at
which a PV array delivers maximum power under a given
temperature and irradiance. In P&O method, the MPPT
algorithm is based on the calculation of the PV output
power and the power change by sampling both the PV
Array current and voltage. The tracker operates by
periodically incrementing or decrementing the solar array
voltage [4]. If a given perturbation leads to an increase
(decrease) in the output power of the PV, then the
subsequent perturbation is generated in the same (opposite)
direction. The duty cycle of the dc chopper is varied and
the process is repeated until the maximum power point has
been reached. Actually, the system oscillates about the
MPP. Reducing the perturbation step size can minimize the
oscillation. However.
MATLAB MODELING AND SIMULATION
The PV Array and the PVIV blocks are embedded
blocks, where the PV array has been mathematically
modelled [4]. These blocks are necessary to calculate the
maximum power point, as part of the MPPT technique and
also to display the characteristics curves based on different
irradiance levels. The same can be implemented for
different ambient temperatures.
CONCLUSION
The PV Array has been mathematically modelled. The
programmes implemented in the MPPT technique achieve
the maximum power point. It has been shown that for the
particular irradiance levels the maximum power delivered
by the PV Array is delivered to the load. The same is
carried out if there is a variation in temperature. It is a
simple MPPT setup resulting in a highly efficient system.
In conclusion, non-conventional energy sources will
dominate the conventional sources of energy in the near
future and here one uses the greatest renewable energy of
all, the sun’s energy.
[attachment=26285]
Abstract
The following paper validates an algorithm for
Maximum Power Point Tracking using Perturb and Observe
technique. The algorithm starts by setting the computed
maximum power PMAX to an initial value (usually zero).
Next the actual PV voltage and current are measured at
specific intervals and the instantaneous value of PV power,
PACT is computed. PMAX and PACT are compared.
PMAX and PACT are compared. If PACT is greater than
PMAX, it is set as the new value of PMAX. At every instant
the PACT is calculated, and the comparison is continuously
executed.
INTRODUCTION
As people are concerned with the fossil fuel exhaustion
and the environmental problems caused by the
conventional power generation schemes present,
renewable energy sources, photovoltaic panels and windgenerators,
to mention a few are now in great need [2].
Among several renewable energy sources, photovoltaic
arrays are used in many applications such as water
pumping, battery charging, hybrid vehicles, and grid
connected PV systems. The principal advantages
associated with photovoltaic arrays are that it consists of
no moving parts. Do not produce any noise and
maintenance costs are minimal. It is also a clean source of
energy. Amount of energy produced by the sun is so large.
P&O MPPT TECHNIQUE
The problem considered by MPPT methods is to
automatically find the voltage VMPP or current IMPP at
which a PV array delivers maximum power under a given
temperature and irradiance. In P&O method, the MPPT
algorithm is based on the calculation of the PV output
power and the power change by sampling both the PV
Array current and voltage. The tracker operates by
periodically incrementing or decrementing the solar array
voltage [4]. If a given perturbation leads to an increase
(decrease) in the output power of the PV, then the
subsequent perturbation is generated in the same (opposite)
direction. The duty cycle of the dc chopper is varied and
the process is repeated until the maximum power point has
been reached. Actually, the system oscillates about the
MPP. Reducing the perturbation step size can minimize the
oscillation. However.
MATLAB MODELING AND SIMULATION
The PV Array and the PVIV blocks are embedded
blocks, where the PV array has been mathematically
modelled [4]. These blocks are necessary to calculate the
maximum power point, as part of the MPPT technique and
also to display the characteristics curves based on different
irradiance levels. The same can be implemented for
different ambient temperatures.
CONCLUSION
The PV Array has been mathematically modelled. The
programmes implemented in the MPPT technique achieve
the maximum power point. It has been shown that for the
particular irradiance levels the maximum power delivered
by the PV Array is delivered to the load. The same is
carried out if there is a variation in temperature. It is a
simple MPPT setup resulting in a highly efficient system.
In conclusion, non-conventional energy sources will
dominate the conventional sources of energy in the near
future and here one uses the greatest renewable energy of
all, the sun’s energy.