Solar Peak Power Point Tracker

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Solar Peak Power Point Tracker
Objective of Project To implement a solar
peak power point tracker for a battery
charging system.

• Design Specifications
• The target PV array is a 60-watts solar
  panel. The panel is field-wired in two halves,
  each delivering a maximum power of 30 watts
  to the battery.
• The battery to be charged is 12 V
  lead-acid.

Characteristics of a Photovoltaic (PV) Panel What
is peak power point (PPP)?? ? A peak power
point (PPPT) is the operating point of a PV panel
where the maximum power is available to
extract at a given insolation level and cell
temperature. How the photovoltaic perform?? ?
The power characteristics of a PV array change
with the meteorological conditions, ie.
insolation levels and cell temperature.
A PPPT should be able to 1. Make sure the
system operate close to the PPP when the system
is subject to variations in environmental
condition. 2. Provide high conversion efficiency.
3. Maintain tracking for a wide range of
variation in environmental conditions. 4.
Provide an output interface compatible with the
battery charging requirement.

• Design of PPPT
• An important issue for design consideration is
  that the output voltage of the PPPT will be fixed
  because of the battery. Peak power point tracking
  is performed by using a boost converter and
  perturbation and observation (PO) algorithm.
• Boost Converter..
• used to vary the PV array terminal voltage
  with pulse width modulation so that the array
  operating point can be moved towards
  the PPP.
• chosen because the battery holds a higher
  voltage than the array terminal voltage at any
  given situations.
• PO Algorithm..
• operates by periodically perturbing (ie.
  incrementing or decrementing) the array terminal
  voltage and comparing the PV output power with
  that of the previous perturbation cycle. If the
  perturbation leads to an increase in array power,
  the next perturbation is made in the same
  direction, otherwise the perturbation direction
  will be reversed.

Since the output voltage of the PPPT is fixed,
the information of the output power can be
obtained just by monitoring the output current.
This implies that PPP tracking can be simply
achieved by maximising the output current!!!
Solar Panel
Boost Converter
Battery
Microprocessor
Boost Converter