PV-standalone monitoring system performance using LabVIEW

Abstract

This paper presents and discusses the performance evaluation, monitoring and analysis of a stand-alone Photovoltaic (PV) system. This experimental investigation achieves its objectives using Laboratory Virtual Instrument Engineering Workbench (LabVIEW) interface capabilities. The installed PV generator system operates in extreme and severe weather conditions. The local area is characterized by a high level of irradiation, high humidity variations, very high ambient temperature and frequent dust storms. Two PV panels of 150 W rating each are used. Each panel feeds a variable resistive load separately and simultaneously. The constructed LabVIEW engine displays environmental parameters and the associated electrical variables (voltage, current and power) on dedicated graph windows continuously in a real time manner. The current versus voltage (I-V) and power versus voltage (P-V) characteristics are taken for any chosen panel, displayed and stored accurately. LabVIEW allows appending any characteristics for the sake of comparison, investigation and research purposes. LabVIEW has shown high performance in communicating with several devices simultaneously and high capability of displaying several variables behavior at a time. The designed virtual instrument (VI) filters are programmed to execute different tasks on a priority basis. The developed system reveals and stores the pronounced impact of dust, the variation of temperature and the irradiation changes on the PV panel power output behavior. The monitoring results are very satisfactory. The online data display in multi-scale window frame is very informative. The online efficiency evaluation is very useful for system operation and analysis. The developed system was found to be very supportive for research and educational purposes.