College - Author 1
College of Engineering
Department - Author 1
Electrical Engineering Department
Degree Name - Author 1
BS in Electrical Engineering
Dale Dolan, College of Engineering, Electrical Engineering Department
The Solar Photovoltaic Current-Voltage (IV) Curve Tracer, sponsored by Cal Poly Professor Dale Dolan, characterizes solar array current vs. voltage curves for any given temperature and irradiance. The curve tracer is battery powered, and functions autonomously across loading conditions from short circuit to open load on any sub-450-watt solar array. The curve tracer supports separate data logging modes for both single cells and single modules to maximize data accuracy for each. For testing full strings of solar panels, up to 10 IV curves may be stored in persistent EEPROM memory. Stored data may be recalled later for output to a personal computer in comma separated value format.
This completed project is designed to teach Cal Poly students about the operation and continued maintenance of any solar array operating within the previously outlined specs during related coursework. This project will allow students to observe the optimal operating point of solar arrays at any temperature, illuminance, and load to identify problems due to mismatch, shading, soiling, and other functional errors. In a laboratory setting, extreme conditions may be tested and characterized to ensure a panel provides enough power and functions at all expected limits
The completed project could successfully characterize IV curves for single cells, record temperature, store 10 data sets, and output data in .csv format to a personal computer, in conjunction with working LCD and button interfaces. The irradiance sensor chosen was unfortunately not compatible with the chosen microcontroller, and Covid distancing gave little chance to test the device on full panels during the design stages. When the final project was tested on a full panel, it was not put in the correct mode for the high panel voltage, and the microcontroller was shorted. Future improvements would include overvoltage protection and a professionally manufactured PCB and chassis.