Transcript Instrumentation Panel Group

Solar Array & Maximum
Power Point Tracker
Group
Senior Design Project 2003
Stephanie Chin
Jeanell Gadson
Katie Nordstrom
Advisor: Karen Panetta
What is a
Maximum Power Point Tracker?
The Maximum Power Point Tracker (MPPT)
optimizes the amount of power obtained from
the photovoltaic array used to charge the
electrical power supply
Why Design a MPPT?
Our design is customized to meet the varying
conditions of solar car racing, i.e. shadows,
over-sun exposure, weather conditions, etc.
Basic Design
The maximum power tracker unit includes the following
components:








Solar Array
Power Supply
PIC Microcontroller
Analog to Digital & Digital to Analog Converters (ADCs and DACs)
Pulse Width Modulator (PWM)
Field Effect Transistor (FET)
Protection Diodes
DC/DC Converters
Solar Array

A solar cell is a semiconductor device that
absorbs the sunlight and converts it into
electrical energy
Power Supply

The solar array charges 4 batteries at a time
PIC Microcontroller


Operates the DACs and ADCs
Computes the power point of the array
according to the I-V curve.

Regulates the Integrated Circuits (ICs)
Converters

ADCs
– Built into PIC
– Changes the analog output of the solar
array into a digital signal

DACs
– Translates the digital output of the PIC into
an analog signal for the PWM
Pulse Width Modulator (PWM)

Controls the FET
Field Effect Transistor (FET)

Our “Light Switch”

Prevents overcharging of the batteries

Determines the current paths between
the solar array, power supply, and ground
Protection Diodes

Prevent the current from flowing back into
the solar array
DC/DC Converters

Boost and Buck Converters which power
the ADCs, DACs, PIC, and PWM
System Specifications

MPPT can handle Solar Array Input Voltage
range 0-200v and max input current of 10A.

The DC/DC Buck Converter steps down the
Array voltage to 5v to power the PIC, DACs,
and RS-232. Similarly, the DC/DC Boost
Converter steps up the 5v input to 12v to
power the PWM.