Design and implementation of an android based automatic phase selector and overload protector using GSM

Abstract

In this century, the demand for electricity is increasing at an alarming rate that has caused pressure on the existing transmission and distribution networks. This has led to power cuts affecting sensitive facilities such as hospitals, industries and schools. This project is designed to automatically supply continuous power to the load through one or all of the three sources of supply that are: solar, mains grid & generator. In case their availability; an android app is used to select the source of choice and when the amount of load demand increases beyond what can be handled by one source, a mobile app is used to bring on board either of the remaining two sources so as to meet the load demand. The output of either source is connected to a voltage stabilizer which stabilizes the voltage to 220Vac by means of an auto-transformer with many taps and then the load is connected through an overload protector circuit which monitors the amount of current drawn. Once the current exceeds normal values, the last load connected is automatically isolated from the source leaving the critical loads connected. At the same time a message is sent to the operator by means of GSM, notifying of the overload. The operator can decide to operate the loads by sending a text message “normal” to restore the system operation to use an android app.