Arduino-based Automatic Transfer Switch for Domestic Emergency Power Generator-Set - A must for an area with frequent electricity service interruption

摘要

The service interruption of electricity interferes with many important daily activities in industri, commercial, governmental sectors, as well as in educational institutions and households activities. It may engender various production losses in industry, loss of international opportunity in governmental political relationship, economy negotiations in commercial field, or even life losses of hospital patients during emergency surgeries. Emergency power supply becomes a must to be owned by each customer to ensure the necessary measures to be taken in case of unscheduled service interruption of power utility. A diesel-generator set (genset), which can be activated when the interruption occurs, is commonly found in many big clients of power utility. It is sometimes equipped with some control mechanism to automatically switch over from the utility power supply to the emergency one, and vice-versa. However, in many small power customers, the switch-over must be done manually. This paper describes the design and construction of such an automatic transfer switch (ATS) being affordable to be built and used by small power customers like in households sector. The ATS has been designed using Arduino-Nano microcontroller, optocoupler as the voltage detector, relays to activate the load contactors to switch-over between the utility power supply and the genset, and a liquid crystal display (LCD) as an indicator. The results show that the ATS could be functioning in transferring the load contactor to the genset in 37.8 seconds and turning on the genset in 2.8 seconds after the interruption of the power utility service. It was also capable to move the load back to the utility power supply in 2.8 seconds and to turn-of the genset in 23 seconds after the recovering of utility power supply.