2025 Volume 104 Issue 12 Pages 159-168
Tidal currents are the result of oceanic flow caused by tides and are a source of renewable energy. The tides reverse direction every half cycle, with one cycle taking between a half day to a full day, depending on location. It is therefore possible to predict the power generated by tidal power generation system. This study presents a tidal power generation system using a doubly fed induction generator (DFIG) under variable-speed operation. Previously studies have investigated the gear ratios and generator capacities for producing maximum annual energy while operating the system under maximum power-point tracking control, constant turbine output control or constant rotor voltage control. In this study, we investigated the gear ratios and generator capacities for producing maximum annual energy while change the constant stator current and the generated maximum current speed. As a result, the annual capacity factor increased as the generated maximum current speed decreased. At the generated maximum current speed of 2.0 m/s, the annual capacity factor was about 38.67% for the constant stator current is range of -1.70 to -1.05 pu. The response of a speed control system employing the gear ratio and generator rated capacity was examined. It was shown that slip and stator d-axis current closely followed the desired values.
