Design and Performance Evaluation of a Solar-Powered Automatic Transfer Switch for Self-Starting Power Backup Systems

The design and performance evaluation of a solar-powered automatic transfer switch (ATS) for self-starting power backup systems is a critical aspect of ensuring reliable and efficient power supply, especially in areas with frequent power outages. This study developed a solar-powered automatic transfer switch (ATS) for household starting system to enable the automatic operation of switching of power supply between a primary power source (PPS) from public utility and a secondary power source (SPS). The alternating current voltage monitoring and control circuit were constructed using the voltage monitoring relay (VMR) as a primary component of the power sensing and control circuit. The VMR assessed the utility supply's voltage level and compared it to a set of voltage tolerance values between 185 and 250V. While a circuit breaker of 12A was used as a switch to the power supply from the main supply end of the automatic transfer switch. A digital millimeter was used to measure the output voltage from the PPS and the supply voltage, and a timer was also used to measure the set time and the actual time the automatic transfer switch takes to switch off the SPS and connect the load and the actual time the ATS takes to switch the load to the main supply when it is available. Results obtained showed that the average system delay period for switching from utility supply to generator is 0.46 second, while the average system delay period for switching from generator to utility supply is 0.275 second. Nonlinear mathematical model equations are also developed for the system. It can be concluded that the transfer switch developed has the ability to track, monitor, control and switch between power sources in few seconds.