Transient starup performance of a micro horizontal axis river hydrokinetic turbine

Using the micro horizontal axis river hydrokinetic turbine to generate electricity is a low-cost power generation mode suitable for remote mountain areas. Startup performance is a key parameter related to annual power generation. Based on the numerical simulation, the influences of damping factor b, moment of inertia J, constant inflow velocity U and irregular inflow velocity (long-period and short-period inflow velocities) on the startup performance of a micro horizontal axis river hydrokinetic turbine are analyzed. Firstly, a decrease in b and J, as well as an increase in U, can reduce time required for startup. The increase of b and U cause the power coefficient Cp increase first and then decrease. The moment of inertia only affects the time required for startup, and has no impact on the Cp of the turbine in stable state. Secondly, for the long-period inflow velocity, an increase in T will result in a gradual increase in the average CP after the start-up is completed, however, the short-period has no significant effect on the mean value of each parameter. Finally, for the short-period inflow velocity, the fluctuation amplitude of hydrodynamic parameters decreases with T rising, but the fluctuation frequency increases.