Control and Flume Flow Experiments of a Tidal Current Energy Converter With an Infinitely Variable Transmission

This study presents a flume flow experimental investigation of operational performances of a tidal current energy converter (TCEC) with a horizontal-axis tidal turbine and an infinitely variable transmission (IVT). A closed-loop speed ratio controller of the IVT is developed to continuously adjust its speed ratio with variable water speeds for a desired constant output speed. Flume flow testing of the TCEC is performed to test validity of the closed-loop speed ratio controller of the IVT under different flow speed conditions. Flume flow testing results show that the speed ratio controller can achieve good control performances with the tracking error less than 2.56% for the given desired output speed. Fluctuations of IVT output speeds caused by variable flow speeds and water turbulence are reduced by more than 91.06% via the continuously varied speed ratio of the IVT and its speed ratio controller. Good operational performances of the IVT can ensure optimal arrangements of operational torques and rotation speeds in the drivetrain of the TCEC with optimal speed ratios under low-speed and high-torque operational conditions.