Dynamic simulation of a direct-coupling 3-blade vertical-axis hydrokinetic turbine with a low speed generator

摘要

This research paper reports a dynamic simulation of a 3-Blade Vertical-Axis Hydrokinetic Turbine for direct-coupling with a low speed generator. Direct-coupling eliminates the gearbox. Various turbine radii were investigated in water velocities ranging between 0.5 and 2 m/s. A simulation program was done in MATLAB to compute the dynamic parameters such as rotational speed, torque produced and response time. Additionally, a S814 blade profile was used but its coefficients were analytically expanded to cover angles of attack ranging from -180 to +180o using computational fluid dynamic analysis. The results were analysed and a diagram was produced to aid the selection of a turbine radius to suit the water velocity. Larger turbines spun at lower nominal speeds with higher torque. However, high water velocity was the most favorable because it gave turbines a faster response time. To determine the turbine radius, generator characteristics such as nominal speed and torque are required. The response time may not be critical in normal operation because the rotor could be spinning constantly for months. However, it will be crucial in the design of the control system.