Designing an Automatic Transfer Switch (ATS) with Electromechanical Relays: A Relay Logic Method with Renewable Energy as the Main Source

This study presents the design and implementation of an Automatic Transfer Switch (ATS) using electromechanical relays, prioritizing renewable energy as the primary source. The research focuses on developing a cost-effective and reliable relay-based ATS, utilizing a relay logic framework for control and performance evaluation through Visual Basic simulations. A comparative analysis with solid-state ATS designs highlights its advantages in terms of cost and reliability. The system comprises renewable energy sources (solar panels), a backup generator, electromechanical relays, a relay logic-based control circuit, and monitoring mechanisms. Proper component sizing was emphasized to ensure robustness and efficiency, with calculations for active power, phase current, and cable requirements. The design supports a 100A load, with cables sized to accommodate both operational and overload conditions. Simulations were conducted within a voltage range of 185–250V, integrating conditional logic for seamless switching between power sources. Results confirmed the ATS functionality, demonstrating stable power supply under normal conditions with voltage monitoring relays ensuring operational stability. In the event of power failure or voltage drop, the ATS smoothly transitioned to the generator. Simulated scenarios validated smooth transitions, effective control mechanisms, and enhanced energy efficiency. Safety features, including power source isolation, minimized wear and ensured long-term reliability. Manual switches and indicators provided additional control and monitoring. The study concludes that the relay-based ATS offers a reliable, cost-effective, and sustainable solution, outperforming solid-state systems in certain applications. The integration of solar PV and wind energy enhances energy efficiency while reducing dependence on non-renewable sources. This research underscores the potential of electromechanical relay systems in modern power management, contributing to sustainable energy solutions.