INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 9, ISSUE 02, FEBRUARY 2020 ISSN 2277-8616 768 IJSTR©2020 www.ijstr.org Improve Continuity Supply Of PV System Using Arduino-Based Transfer Switch Syafii, Sisri Anisar Putri, Yona Mayura Abstract: This paper presents the design and construction of a new power transfer switch mechanism for solar home system based on the Arduino controller to improve PV system continuity supply. The purpose of this study is to provide PV system as the main source and the electricity from State Electricity Company (Perusahaan Listrik Negara, PLN) as a backup source. The Arduino controller is used to improve the continuity of electricity supply. The measurement results of DC voltage sensors have been calibrated in a laboratory environment and the results fulfill the IEC-61724 minimum- accuracy. The power transfer has been designed to move to PLN supply when the battery remaining capacity 30 % obtained from the battery open circuit voltage which can be calculated using internal resistance prediction. The transfer switch then moves back to PV system after 35% of battery remaining capacity obtained from battery no-load voltage. The test results on various types of loads show that there was no interrupt and voltage sag during the switching process. The duration of PLN outages index is around two hours/time interruption, thus the 30 % setting PV battery SOC enough to cover PLN interruption. Therefore, the Arduino-based power transfer can improve the continuity of electricity supply. Index Terms: Power Transfer, Transfer Switch, Arduino Controller, Improve Continuity of Electrical Supply. ——————————  —————————— 1. INTRODUCTION INDONESIA is a largest tropical archipelago country. The number of islands in Indonesia is approximately 17,000 islands [1] with a population of more than 250 million and spread over more than 65,000 regions and islands. One of the important needs in people's lives is the availability of electricity. Almost all community activities currently depend on electricity, both in office activities, households and other activities. The importance of this electrical energy makes electricity consumption increase every year. One effort that can be done to meet these needs is by utilizing a plant with renewable energy sources. Renewable energy is energy produced from sources that are not depleted or can be refilled. Indonesia has great potential to have renewable energy sources to produce electrical energy which Indonesian government policy have target in 2025 that 23% of generation mix is renewable energy. The abundant renewable energies in Indonesia is solar energy. This is due to Indonesia's geographical location across equator line, therefore photovoltaic is one of the feasible resources [2]. The utilization of sunlight energy as an alternative energy source for electricity generation is an extraordinary breakthrough. Because the sun is a very large energy source and the utilization of solar energy does not have a negative impact on the environment. With the location of Indonesia in the equator, Indonesia will always be exposed by sun around 10 to12 hours a day [2]. This makes it possible to make the solar power plant as the main source for electricity supply. In producing electricity, solar power plants are very dependent on the intensity of solar radiation. The intensity of solar radiation is best when the weather is sunny. When sunny weather per m2 solar panel produce daily average energy conversion higher than 6 kWh/m2. Whereas when the weather is not clear, the energy produced is not as much when the weather is sunny i.e less than 5 kWh/m2 [3]. The uncertainty of the power produced by this photovoltaic can disrupt the continuity of electricity distribution. Therefore, a utility power source is still needed to back up the main supply and ensure the sustainability of operational process. A controlled power transfer of critical load to prevent supply interruptions from main source or backup source, which a system can work automatically is needed [4]. This system is usually called Automatic Transfer Switch (ATS) [5]. The current power transfer development and research have use the utility grid as main source and generator as backup source [6][7], to switch emergency power supply of vehicles [8] and for high voltage load transfer. Some application has disadvantage of not using renewable energy sources as the main electricity source, even though renewable energy sources, especially PV system, have the potential to be the main electricity source. In addition, the existing power transfer moves the supply to the backup source when the electricity is completely off there is no option for operation settings. Power transfer switch commonly used for transferring energy supplies from national grid to generators is imported products made in Canada or the United States, which are quite expensive. In addition, this transfer switch cannot be reset according to requirements. Therefore, as an alternative in this study a power transfer has been designed which can be arranged by Arduino at a more economical price. The results of the design test will be presented in this articleRenewable energy is energy produced from sources that are not depleted or can be refilled. Indonesia has great potential to have renewable energy sources to produce electrical energy which Indonesian government policy have target in 2025 that 23% of generation mix is renewable energy. The abundant renewable energies in Indonesia is solar energy. This is due to Indonesia's geographical location across equator line, therefore photovoltaic is one of the feasible resources [2]. 2 ARDUINO-BASED TRANSFER SWITCH The Automatic Transfer Switch is an electromechanical equipment that can be controlled and that is used to move the position of the power source from the main grid of PLN to a backup power source when the electricity supply from the utility grid network is cut off. Automatic Transfer Switch will return the power supply to the normal position automatically if the electricity supply from the utility network has returned [9]. ————————————————  Syafii, Electrical Engineering Department, Engineering Faculty, Universitas Andalas. Padang, Indonesia. E-mail:syafii@eng.unand.ac.id.  Sisri Anisar Putri, Electrical Engineering Department, Engineering Faculty, Universitas Andalas. Padang, Indonesia. E-mail: sisrianisarputri@gmail.com.  Yona Mayura, Electrical Engineering Department, Engineering Faculty, Universitas Andalas. Padang, Indonesia. E-mail: yonamayura14@gmail.com.