| Abstract | The main goal of this project is to provide a solution to make medications requiring refrigeration more readily available in rural communities in Nicaragua, where a great portion of the rural population has no access to electricity or adequate healthcare services. The proposed solution is a solar-powered solid-state refrigerator that is low cost, low power, and easy to use and repair. The project was split into two components: refrigeration and control system. The development of the control system is described here. To select an appropriate control method, the on-off control scheme and a proportional control scheme were compared. A proof-of-concept verification test allowed for the observation of the steady-state and impulse response of the refrigerator system using different control methods. The proportional control scheme is shown to consume less power during steady-state operation. An energy balance analysis was also conducted to ensure that the energy demand and supply are matched using one solar panel. The energy balance demonstrates that one solar panel can provide sufficient energy for the clinics to use a refrigerator. Although this project demonstrated the superiority of the proportional control option, further work is required to refine the control method selected. |
