Development of an Intelligent Electronic Load Controller for Stand-Alone Micro-Hydropower Systems

People living in rural and remote areas of Sub-Saharan Africa generally lack access to electricity due to their geographical location and the costs associated with connecting these areas to the national electrical grid. A viable technology to supply electricity to some of these areas are stand-alone micro-hydropower systems which harnesses energy from flowing water. Self-excited induction generators (SEIGs) are commonly used for the generation of electricity in stand-alone micro-hydropower systems. The electricity supplied by a SEIG to the demand side i.e. the load needs to be maintained stable under various consumer load conditions. This is accomplished through the use of an electronic load controller (ELC). This paper presents the design and development of an intelligent ELC that is able to maintain stable voltage on the demand side of a 3-phase SEIG supplying varying single-phase consumer loads. The proposed intelligent ELC consists of an uncontrolled bridge rectifier, filtering capacitor, chopper switch, voltage sensor, optocoupler, Arduino microcontroller and a ballast load or storage, depending on site-specific requirements and economic viability. The fuzzy logic control method is implemented to maintain stable and reliable voltage. The ELC is designed and simulated under various consumer load conditions in Matlab/Simulink. Simulation results of the ELC model are verified experimentally in a laboratory setting. The proposed intelligent ELC will contribute towards providing reliable and cost-effective means of enhancing the proliferation of micro-hydropower particularly in rural and remote applications in Sub-Saharan Africa.