Nobuyasu Sakata

Development of the integrated simulation tool for behavior and loads estimation of ocean current power plant

Owing to huge amount of kinematic energy, ocean current has the potential to be a base power source. However, ocean current power plant has to be submerged in the sea, making it difficult to maintain; therefore it must have high durability and reliability for long-term operation towards utilization. Equipment design approach considers various loads which occur during normal operation of the plant such as start-and-stop or emergency stop. Loads such as force on blade, buoyancy on float, drag force on cable and resistive force on mechanical drive-train and dynamo dynamically interact with each other and are affected by ocean current conditions. In this paper we have developed an integrated simulation tool to estimate the behaviors and loads on the components of ocean current power generator. It consists of six subsystems and each one can be simulated individually. By integrating all state function between subsystems, simulator is able to balance and converge dynamic equations and evaluates the electric-generating capacity, loads on equipment and behavior of the float. The simulator is verified for accuracy by comparing with tow tank scaled model. It was found that change in current speed and pitch angle of the float matches well with the simulation result.