Development of a Hybrid AC/DC Residential Electrical System

In pursuit of supporting the global efforts in reducing carbon footprint and reliance on fossil fuels, this thesis seeks to continue the development of a hybrid AC/DC house prototype at Cal Poly State University. In particular, this thesis presents improvements on several aspects of the house. To enhance the power flow to DC loads, a dedicated 48 V DC bus was constructed to replace the impractical multiple DC buses in the previous system. This iteration also added a key feature that enables users to monitor real-time AC and DC powers. Another new functionality involves the provision of a mix of latching and non-latching relays to switch between sources, thus ensuring that both AC and DC loads receive power. This new feature further enables users to conveniently observe the system status and select which sources are utilized from a touchscreen. Other improvements entail the integration of a control system with a Raspberry Pi and Arduino Nano and a touchscreen human-machine interface to control main components in the system. Results from hardware tests revealed that most of the improved components and new features performed well. Design, component selection, and development of the improvement tasks will be discussed in this report, including technical issues encountered. Future work to further improve the system will also be presented. When fully completed, the hybrid AC/DC house will not only serve as a living laboratory to educate students and the community on residential electrical system but will also serve as a demonstration site of a future Net Zero Energy Home.