An Internet of Things based system to control load shedding for undersized generators in public hospitals.

Abstract

In Uganda, majority of the infrastructure and equipment in public hospitals are acquired through donations. The donors usually provide backup generators sized according to these infrastructure, and as the load increases, these generators get undersized. This project focused on addressing the challenge of an undersized generator supplying power to a public hospital during a power outage. The objective was to develop an efficient load shedding control system that prioritizes critical loads while gradually shedding less critical loads over time. The project involved the design and implementation of a prototype that consists of two systems i.e. the fuel measurement system and the load control system. The fuel measurement system uses an ultrasonic sensor to measure fuel and then sends these readings to a NodeMCU. The NodeMCU wirelessly sends the fuel readings to another NodeMCU (main microcontroller) via a Wi-Fi connection. The load control system uses voltage and current sensors to measure voltage and current of each load category. It thereafter uses relays to turn on and off the loads. Load monitoring and manual control is also possible over a web UI. It was discovered that load categorization in the hospital was present although load shedding decisions were hardly implemented and the undersized generator was dormant. We recommend further conducting of load assessments, fostering collaboration among hospital departments and designing a flexible load shedding strategy. The project emphasized the importance of communication, training, and continuous monitoring to ensure effective power management during emergencies. Future work includes, incorporating alternative power source in case of a power outage and generator failure, monitoring other parameters such as frequency and quality, and energy storage integration. The project’s outcomes aimed at enhancing the hospital’s resilience, minimizing blackouts, managing resource utilization, and improving patient care during grid outages.