Benefits of battery hybridization in hydraulic turbines. Wear and tear evaluation in a Kaplan prototype

Kaplan turbines are nowadays used to provide Frequency Containment Reserve (FCR) to the grid due to their fast capacity to regulate their power maintaining high efficiency. However, this continuous power regulation in-creases the wear and tear of the regulation system considerably. To reduce the amount of movements in the regulation servomotors, and thus their wear and tear, a new technology is being investigated within the frame of the European project XFLEX Hydro. This new technology is based on hybridizing the hydro unit with a small size battery in parallel, this one being in charge of compensating the small frequency fluctuations in the grid by providing or absorbing power. In this paper, the benefits of the implementation of this new technology are evaluated. A Kaplan turbine prototype located in Vogelgrun, France, has been hybridized and different param-eters have been monitored while the unit was working in hybrid mode and in normal standalone hydro mode. Wear and tear of the regulation system have been compared for both hybrid and standalone hydro modes. A reduction of about 25% in servomotors mileage and of 50% in fatigue damage have been obtained by hybridizing the unit.

Automated summary

This study investigates a new technology that hybridizes a hydro unit with a small battery to reduce the wear and tear of the regulation system in Kaplan turbines. The battery compensates for frequency fluctuations in the grid by providing or absorbing power. Experimental results show that hybrid mode reduces the wear of servomotors compared to standalone hydro mode.