Development of Pneumatic Technology for Automation and Control of Small Hydropower Plants

Resumo

Small hydropower plants have been seen as a more sustainable source of energy in comparison with large hydropower plants due to the smaller required flooding area. However, every source of energy production has, inevitably, an impact on the environment. Aiming to reduce the usage of fossil-based products, such as hydraulic oil, a joint effort has been made between the Laboratory of Hydraulic and Pneumatic systems and the companies Reivax Automation and Control and China Three Gorges, in order to introduce the pneumatic technology to the hydrogeneration sector. Characteristics such as easy installation and maintenance, low acquisition costs, and mainly, low environmental impact, make the pneumatic technology an excellent candidate to replace the hydraulic servo actuators that have been traditionally used for automation and control in hydropower plants, which use large quantities of hydraulic oil and provide a high risk of a river bed contamination due to possible leakages or incorrect disposal of hydraulic oil. This paper presents two cycles of development of a pneumatic solution to automate and control the generating unit of small hydropower plants. It includes the first proposed solutions, proof of concepts and drawbacks that were faced, as well as the new challenges and achievements that rose during the design process. The paper also presents the most up-to-date results from a pilot project where a fully pneumatic solution was applied for a generating unit with 438 kVA of generating capacity and a model of development that was identified based on common activities performed during the first two cycles of development.