A Multi-String Photovoltaic Current-Voltage (I-V) Curve Tracer

Abstract This paper presents the design and the development of multi-string I-V curve tracer for photovoltaic (PV) strings. It uses a capacitive load and double pole relay to measure the I-V characteristics of a multiple PV strings simultaneously. The prototype is developed using a PIC18F4550 micro-controller and a graphical user interface GUI designed using Microsoft’s Visual Studio software. The I-V characteristics of the PV string are displayed on LCD (Liquid Crystal Display) and computer. The performance and functionality of the proposed I-V curve tracer have been tested using four PV strings. The experimental test shows that the proposed I-V tracer can measure and display the I-V characteristic of each PV string smoothly in the normal and shading conditions.