Artificial vision wireless PV system to efficiently track the MPP under partial shading

Abstract

The solar photovoltaic industry is booming and the achievement of high efficiency in this kind of systems is crucial. Partial shading conditions complicate the search of the maximum power point (MPP) of the installations due to the existence of multiple peaks in the P-V curve. In addition, these photovoltaic (PV) systems require monitoring and control in real-time to guarantee the correct operation. Thus, this paper proposes a novel system to track the maximum power point through artificial vision, under partial shading conditions controlled and monitored by a wireless sensor network based on IEEE 802.15.4 technology. The infrastructure consists of a wireless distributed photovoltaic system (WDPS) where the power converter is connected to a sensor node that sends the information to the coordinator node. The coordinator node is connected to a webcam and a Raspberry Pi. This part of the system is called wireless webcam centralized control (WWCC) and is responsible for processing the sensors information and the images. Besides, the WWCC sends the control signal. The wireless communication is set in beacon-enabled mode allowing synchronization between the sensor nodes and the coordinator node. Moreover, the guaranteed time slot mechanism provides the correct transmission of data with low latency, ensuring the stability of the controller. Experimental tests have been carried out to validate the artificial vision wireless PV system. The results prove an appropriate operation, achieving an MPP tracking higher than 99%, even in partial shading conditions.