Advanced Control of Hydroelectric Power Plants

Hydro-power accounts for a significant fraction of electric energy consumed in many countries, mainly in Canada, USA, Norway and Brazil. This aspect will persist in the world energy mix for many years considering the hydro resources yet to be explored, mainly on the amazon basin, and the diffusion of Small Hydro Power Plants. It is estimated that a total capacity of 1000 GW will be installed by 2050, mainly in Africa, Asia and South America, and a similar amount will be modernized and refurbished, representing a massive potential contract volume for suppliers of hydro equipment.Social pressure for the adoption of clean energy, with reduced emission of greenhouse gases, reducing the dependence on the producers of fossil fuels, and a natural capability for storage and controllability, puts hydro-power in advantage as an alternative dispatchable renewable source of power. Nowadays hydro-power seems to be the unique reversible source of renewable power with high dynamic storage capacity and cold start capability, ideal to complement other sources of intermittent non-dispatchable distributed sources of power, like wind and solar. In addition to preserving their stability by the provision of advanced ancillary services like rotating inertia, hydro-power must comply with increasing conformity criteria for quality of energy in the interconnected grid.To study this issue, this text develops dynamic models of many types of hydro-power plants and addresses not only the traditional mechanical and electronic turbine governors, but also the modern digital control systems based on software, integrated to plant Joint Control and remote Automatic Generation Control (AGC) systems. The approach is independent of the technology of the speed governors, Joint Control and AGC, but with concrete examples from all the technologies: mechanical, electronic and digital. Several generations of control systems are modeled and analyzed, even those not used in new installations. Many of them are still in operation and will stay for many years in the future.Concepts from compressible and uncompressible hydraulics of continuous fluids are developed in the text as needed. Modern and classical control theory are used, for continuous and discrete systems, according to the need of each model. The book applies both classical techniques – Bode diagrams, Nyquist criteria, Routh-Hurwitz graphs, root locus, and gain and phase margins – and techniques of modern control – from state space models, stability, controllability and observability, including recent methods of optimal control – fuzzy, robust and immune to load and parameter variation. In addition to theoretical aspects of Control Engineering, emphasis is given to modeling of electrical, mechanical and hydro-dynamical phenomena of the power plant and their controllers, mainly with respect to practical aspects needed to performing tests in turbine and their governors for maintenance, commissioning, model tuning and parametrization. A bottom-up approach is developed, beginning from the modeling of the hydraulic systems of the power plant until the wide-area interconnected hydroelectric systems, with AGC and energy interchange among regions.The book has been used as a reference source for hydro-power tutorials delivered by the author as an associate of Tecnix. It is also used as a reference about hydro-power modeling and control, and optimization of water turbine speed governors of interconnected hydro power plants. Its contents reflect the author practical experience as a manager of the automation department of a large hydroelectric utility, and as a post-graduation teacher of Automation, Control and Supervision of large hydro-power plants in South America and Africa, and as the international chairman of Study Committee on Protection and Automation of CIGRE (International Council on Large Electrical Power Systems), and from technical interchange with many research centers and power plants around the world.