Hydroelectric power plants are known for their ability to cover variations of the consumption in electrical power networks. In order to follow this changing demand, hydraulic machines are subject to off-design operation. In that case, the swirling flow leaving the runner of a Francis turbine may act under given conditions as an excitation source for the whole hydraulic system. In high load oper...

The present hydraulic variable-pitch mechanism of wind turbine uses three hydraulic cylinders to drive three crank and connecting rod mechanisms respectively; the blades are moved with the cranks. The hydraulic variable-pitch mechanism has complex structure, occupies a lot of space and its maintenance is trouble. In order to make up for the shortcomings of hydraulic cylinder variable-pitch syst...

The importance of renewable energy sources for the electrical power supply has grown rapidly in the past decades. Their often unpredictable nature however poses a threat to the stability of the existing electric grid. Hydroelectric powerplants play an important role in regulating the integration of renewable energy sources into the network by supplying on-demand load balancing as well as primar...

Acoustic resonances in Francis turbines often define undesirable limitations to their operating ranges at high load. The knowledge of the mechanisms governing the onset and the sustenance of these instabilities in the swirling flow leaving the runner is essential for the development of a reliable hydroacoustic model for the prediction of system stability. The present work seeks to study experim...

The objective of the paper is to develop a novel intelligent pitch control system of a 2MW wind turbine driven by variable-speed hydraulic pump-controlled system. For realizing the intelligent pitch controller, self-organizing fuzzy sliding mode control, which combines fuzzy sliding mode control and self-organizing modifier, is proposed. In order to verify the proposed concept experimentally, a...

Sediment erosion not only reduces efficiency and life of hydropower turbines but also causes problems in operation and maintenance. Several factors are responsible for this erosion in hydro turbine components. This paper presents the sediment erosion types in hydraulic turbines and their components based upon an extensive literature review and the field observation at Cahua hydropower plant, Pe...

Fast response of hydraulic turbines is a key condition for the integration of renewable sources of energy. In this paper, a new start-up strategy is proposed for hydraulic turbines prone to ”S” instability. This method is based on a complete nonlinear model of the turbine together with the upstream water pipe. More precisely, the control strategy is based on a gain scheduling approach that is c...