IoT Cloud-Based Portable Power Quality Monitoring System With Dual-Path Wireless Communication

Abstract

This paper presents the development and validation of an IoT cloud-based portable Power Quality Monitoring (PQM) system for low-voltage three-phase and single-phase electrical distribution networks. The design phase integrated the set of parameters and aggregation procedures specified in the IEC 61000-4-30 standard for Class S statistical surveys. The printed circuit board developed for the portable PQM system also adheres to the IPC-2221B and IEC 60664-1 design standards, with a documented galvanic isolation barrier between the power grid interface and the digital processing stage. The measured parameters include RMS voltages and currents, phasor diagram, phase angles between the signals, phase frequency, active, reactive, and apparent power, power factor, VTHD, ITHD, voltage and current unbalance, voltage sags, swells, interruptions, and device deployment location. The portable PQM is powered by the power network being monitored; in the event of a power outage, it automatically switches to an integrated backup battery, guaranteeing uninterrupted measurement and data transmission. The acquired data are transmitted to an IoT cloud platform via Wi-Fi or 4G LTE using the MQTT protocol, with automatic failover between routes. An SD card buffers data when connectivity is lost and retransmits them chronologically once connectivity is restored. Laboratory experimental tests conducted with a three-phase AC induction motor and a single-phase nonlinear load showed measurement agreement within 1 % with respect to a Class S commercial power quality analyzer for all electrical parameters analyzed. Furthermore, it was verified that no measurement records were lost during communication failure tests or power outages.