PECM Issue 14 2015 | Page 33

Turbine System Program” (AHTS) which aims to develop technology to maximise the use of hydropower while minimising the environmental effects. Refurbishment of existing turbine assemblies can now include the latest materials technology such as the High Velocity Oxygen Fuel (HVOF) coating system, which uses tungsten carbide materials. This and other similar coating and wear protection systems can be used to protect water turbines and draft tubes against erosion from water-born sediment and reduce cavitation effects for Pelton, Kaplan, and Francis turbines. Improving generator efficiency Advances have been made in the design and construction of the high voltage stator coils used within the generator, which can provide improved efficiency and reliability. The manufacture of high voltage coils is a very precise science; design and construction methods will vary between suppliers, as will the testing procedures, which form the bulk of the proof the client has of the quality of the finished product. Obviously, when repairs are unplanned, speed is crucial in getting the BELOw Improved generation ef f