With continued deployment of variable solar and wind generation, hydropower will play an increasingly important role in system load balancing, regulation and storage. Hydropower can provide excellent response to variable demand requirements, as evidenced by pumped-storage projects. Wear and tear acceleration associated with more frequent flexible deployment of aging hydropower assets, however, will increase. Accelerated aging of generators components, cavitation of runner blades, increased wear of bearings through higher levels of vibration, hydraulic governor reliability, and transformer failures are examples of damage that can be linked to increased unit starts and more frequent load changes. The effects on low temperature, low speed hydro components differ from the thermal and mechanical fatigue related to operational flexibility of thermal plants.
This project will create new learnings by assessing the extent of the accelerated wear and fatigue caused by increased flexible operation and hydro asset cycling damage mechanisms. The research aims to provide hydro owners and operators with information necessary to make educated decisions for operating regimes and the costs associated with them. This project will focus strictly on the needs of generating equipment used in conventional and pumped-storage hydropower.
Information on accelerated wear and tear of hydropower generating equipment will be assessed by using established practices and principles of hydraulic and mechanical design such as computational fluid dynamics (CFD), finite element analysis (FEA), and fatigue modeling. These methods are standard in modern design of hydropower components by original equipment manufacturers (OEMs). By assessing each of the major components in a hydroelectric turbine as it experiences forces, we can measure vibration and fatigue due to transient conditions caused by cycling, and comparable aging of these components against expected wear and tear of base load or best efficiency point (BEP) operations. Flexible operations would consider the start/stop cycle of the unit, minimum load, pumps, etc. Further studies could be performed on thermal fatigue of generator components along with wear due to increased cycling of breakers, transformers and control systems.