Despite of the technological advancements on renewable energies and integration of those into the grid, there are still around 800 million people who lack access to the electricity. In order to tackle this problem, solar home systems are being deployed especially in rural areas to create units for decentralized energy generation, based on DC microgrid premises. Integration of solar home systems, especially in developing countries, has great positive effects on communities' economic and social conditions.
In line with transition to cleaner energy resources and utilization of these, this thesis has been carried at DC Opportunities RD to facilitate the rural electrification project. Within this project, the thesis focuses on implementation of a general adaptable firmware based on USB Type-C power delivery protocol on several components of modular solar home system.
Firstly, the report analyses the existing solar home systems with their characteristics on power delivery and energy management. The limitations on the existing projects are studied and the main motivation on deploying the firmware is pointed out. The main objective of the thesis is hence is formulated as achieving and implementing the USB Type-C power delivery protocol with data acquisition layer on prototypes of charging station, power banks and charging hub, that is tailored to rural applications. The firmware design topology is followed to take into account the modularity, scalability and applicable to energy management.
The USB Type-C power delivery firmware is developed by studying and adapting two open source packages. Several adaptation layers are developed and the firmware is implemented using micro controllers, from STM32, that are capable of running operating system with no faults, deploying several layers of tasks and state machines. Power delivery library functions are tackled with layers of software architectures and data monitoring and transmission layer is deployed, in order to validate the system as well as the hardware.
Implemented firmware is developed on the prototypes and tests are run with the current editions of the prototype. The energy management layer and formulated test case will be run and tested on March 2020, in the field test in Ethiopia. This field test will provide results and data, thanks to the developed firmware and acquisition system, in order to achieve a step closer to the ultimate goal of the project, which is implementing low voltage DC microgrid in rural areas.