부산대학교 도서관

This study discusses the energy billing system for charging station based on IoT (Internet of Things) technology. This charging system uses virtual balances for transactions between the customer and the seller of the charging station. The customer charges the electric vehicle by ordering a charging station at the nearest place and then charging the electric vehicle according to the desired balance amount. The charging station is PV based off-grid system, that is connected to smartphone via google firebase cloud. The smartphone application on this study is separated into 2 (two) sections, in particular the seller application (the proprietor of the charging station) and the customer application (the electric charger). The percentage of error in energy, power, voltage and current readings of the PZEM-004t sensor shows an average error of 1.399% for the energy reading value, 1.55% for the power reading value, 0.289% for the voltage reading value and 1.273% for the reading value. current reading. While, the results of compatibility testing on android 7, 10 and android 11 show that the application can run well even though it is installed on various smartphones.