Module-level health monitoring of solar PV plants using LoRa wireless sensor networks

[摘要] ENGLISH ABSTRACT: The monitoring of PV plants is a crucial aspect in ensuring smooth operation and optimume ciency. Early detection of faults or ine ciencies can greatly reduce downtime and increaseoverall plant e ciency. Faults include temporary and permanent soiling, shadowing,anomalous ageing and critical electrical or mechanical faults. Many solar installations arelocated at remote locations; faults often go unnoticed and unattended to for long periods. Aremote module-level monitoring system can detect ine ciencies and faults when and wherethey occur.A wireless module-level monitoring system that measures electrical and environmental quantitiesrelated to PV module performance is proposed in this work. Although various wirelessmodule-level sensor approaches exist, the sheer size of a typical solar PV plant presentschallenges for the wireless technologies presented in these approaches. Di erent wirelesstechnologies such as Bluetooth, Zigbee, Wi-Fi, GSM, Sigfox and LoRa were evaluated forthe proposed monitoring system. LoRa was chosen as the wireless technology due to its longrange and low power consumption.A number of sensor nodes and a gateway was designed, built and tested. Each sensornode is capable of measuring voltage, current, irradiance, ambient temperature, moduletemperature, orientation and tampering detection. Initialeld tests that were carried outindicate that the sensor nodes measure with adequate accuracy to evaluate PV moduleperformance in detail. The developed monitoring system consisting offteen sensor nodes,a gateway and a remote GUI application was tested on a operational PV plant. Shadingand soilingeld scenarios, as well as a shading experiment proved that the module-levelmonitoring system is capable of detecting faults and ine ciencies within a PV plant.Results that were obtained indicate the following: sensor nodes are modular, self-poweredand low maintenance. The wireless technology used to transmit measurement data from thesensor nodes to a central gateway is capable of operating on a small, medium or large PVplant. The monitoring system is also capable of remote detection and reporting via the GUIapplication.

[发布机构] Stellenbosch University