Induction Machine Driven Pump Applied as Turbine in Micro-hydro Power Plants

There is a potential for increasing energy efficiency, as well as financial cost-effectiveness of modern water distribution networks, irrigation systems, wastewater treatment plants and intense water usage industries in general, by incorporating micro-hydro turbines in certain points of the system where excess pressure is traditionally dissipated via pressure relief valves. Induction motors used as generators coupled to pumps used as turbines are widely spread in these applications, due to their low cost, robustness, and relatively simple operation, either connected to grid or in island mode of operation. The paper presents analytical and model-based considerations of an induction machine in micro-hydropower system through various operating regimes.