IoT monitoring and control system of Distribution Transformers in Rwanda

Abstract

In developing countries, many customers do not get good quality of electricity power supply due to frequent and prolonged power fluctuations/cuts. Distribution transformer (DT) is a service transformer that provides the final voltage transformation in the electric power distribution system, stepping down the voltage to the level used by the customers. Monitoring and control of DT (as a crucial and expensive asset in the network) is a key enabler of power stability to consumers. A power utility is said to be a business oriented with good image representation if it delivers a reliable and affordable electricity. Modern technologies such as the Internet of Things (IoT) offer a wide range of applications in the energy sector to smoothly monitor, control and optimize processes. Currently, many energy companies in developing countries are not yet implementing the remote system to control and monitor the secondary side of DTs and timely get the notifications of fluctuations/abnormalities occurred on those DTs. That is why it is still challenging and time consuming to intervene urgently and do the necessary actions to prevent severe and prolonged power cuts/fluctuations and safeguard the damage of DTs themselves with customer's appliances connected on those DTs. The secondary side of DT is the one connected directly and supply power to the customers. For this reason, we developed an affordable IoT system that automatically detects the abnormalities/fluctuations of three core technical parameters of DT (which are voltage, current and temperature) using current sensors, voltage sensors, and temperature sensor with ATmega 328P Microcontroller to collect and process data from sensors connected to DT system. Once one or all of those technical parameters become abnormal, the system cut off automatically the secondary side of DT in 2 seconds to isolate and protect the customers’ load with safeguarding DT itself using a power relay. At the same time, GSM/GPRS module uploads the sensed abnormal data to the cloud storage, displays them on web-based application for visualization, and sends the corresponding short message service (sms) to notify the issue to the authorized person in 5 seconds for speeding up the interventions and power restoration. In case there is a movement related to the vandalism in the compound of DT, a PIR sensor detects the human motion then a camera takes the related picture and send it to the utility with the corresponding sms. A buzzer generates an audio signaling to warn the culprit/criminal until he left the site. If there is no abnormality detected, the system keeps sensing without sending the data to the cloud. We can open and close remotely the secondary side of DT and buzzer. This system is powered using a rechargeable battery.