Development of an intelligent electronic load controller for stand-alone micro-hydropower systems

M.Phil. (Electrical Engineering)Abstract: 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 can be accomplished with the use of an Electronic Load Controller (ELC). This dissertation presents the design and development of an intelligent ELC that can maintain a stable voltage on the demand side of a 3-phase SEIG supplying varying single-phase consumer loads. The intelligent ELC consist of an uncontrolled bridge rectifier, filtering capacitor, chopper switch (IGBT), voltage sensor, current sensor, optocoupler, Arduino microcontrollers and a ballast load or storage, depending on site-specific requirements and economic viability. A fuzzy logic control method is implemented to maintain stable and reliable voltage supply. Hardware-inthe- loop simulations were carried out under various consumer load conditions using MATLAB/SIMULINK to analyse and test the efficiency of the system in real-time. Laboratory experiments were carried out and it was found that the Intelligent Electronic Load Controller was able to respond quickly and efficiently to changes in the consumer load to maintain the voltage on the demand side of the three-phase self-excited induction generator very stable and close to the set point voltage value. The 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