A LOW COST MICROCONTROLLER-BASED AUTOMATIC TRANSFER SWITCH FOR PORTABLE GENERATOR

Abstract

Automatic transfer switch is electro-mechanical controllable apparatus used to transfer electrical supply from utility netrvork to sccondary supply such as gencrating set rvhcn utility netrvork supply fails. This apparatus automatically switches its contacts to utilify supply if electricity from utility network returns back to normal. Local-made automatic transfer switch for portable generator is not available in the market, however the imported one is offered at costly price. This condition drives people.to use manual transfer switches for controlling their portable generators. This paper presents microcontroller rbased automatic transfer switch for portable generator wich is designed to meet cost effective product. The design is based on ATNIEL ATtiny2313 micro-controller platform with 2 (two) units of 30-ampere power contactor as actuators so that porver capacity of the apparatus reaches 6600 volt-amperes at 220 volt working voltage. Several functional tests conducted in the laboratory show that the apparatus successfully makes transition between the two sources of electricity at the right time-