An embedded microcontroller unit for PV module monitoring and fault detection

Abstract

This paper presents the architectural layout and functional design details of a microcontroller embedded electronic monitoring system (e-EMS). According to the design, this unit is integrated into the PV module junction box. It can be scaled up to form part of a complex PV power plant control system. The communication topology follows a 3-tier structure. It uses two processors, one dedicated for data acquisition and the other for communication purposes. The e-EMS provides a complete set of data associated to PV module performance characteristic parameters, including current and voltage of the PV module and each sub-string of cells, operation of the bypass diodes along with the corresponding current and voltage measurements, PV temperature and environmental parameters. The sampling rate can be programmed in a large range from 1 to 65s along with the number of samples used for averaging signal values. The power output is determined every hour, as a basic output of the system. Comparison of the determined values with the expected ones when normalized to the PV operating conditions provides reliable information on deviation trends, the degree of degradation that the PV module experiences, while the analysis of the sampled data may identify the cells or modules which experience degradation and disclose types of factors which affect their operation.

A Novel Strategy for Monitoring a PV Junction Box Based on LoRa in a 3 kW Residential PV System

“…In the PV system configuration, continuous monitoring was performed by focusing on the power conversion device. On the other hand, additional monitoring of the PV array output and PV junction box composed of diodes and fuses, has not been performed for a long time [9]. In a PV system, the PV array generates a lower voltage compared to the DC-link and grid voltages.…”

Design of an Ultra-Low Powered Data-Logger for Stand-Alone PV Energy Systems

“…This advancement leads to the addition of more components in the design and results in extra power consumption of the system itself. Some of the authors have also discussed this issue and tried to reduce the power consumption of data-logging and monitoring systems [7], [8]. Stand-alone PV energy systems are normally installed at remote locations and have a limited energy availability, so reducing the power consumption of a datalogging and monitoring system can support this field.…”