초록 ▼

A single-blade or double-blade cycloidal turbine can operate as a wave generator or a wave energy converter. Efficient operation techniques can adjust a pitch angle, a radial size, and/or a depth of the cycloidal turbine according to the height and wavelength of an incoming wave. The rotation of the

A single-blade or double-blade cycloidal turbine can operate as a wave generator or a wave energy converter. Efficient operation techniques can adjust a pitch angle, a radial size, and/or a depth of the cycloidal turbine according to the height and wavelength of an incoming wave. The rotation of the cycloidal turbine can be controlled so that a rotational period of the cycloidal turbine matches the period of the wave and so that a target difference is maintained between a rotation angle of the cycloidal turbine and a phase angle of the wave.

대표청구항 ▼

1. A method of operating a wave energy converter, the method comprising: measuring a period and a phase of incoming waves; andcontrolling rotation of a hydrofoil that is mounted on the wave energy converter at an offset from a rotation axis of the wave energy converter, wherein the rotation is contr

1. A method of operating a wave energy converter, the method comprising: measuring a period and a phase of incoming waves; andcontrolling rotation of a hydrofoil that is mounted on the wave energy converter at an offset from a rotation axis of the wave energy converter, wherein the rotation is controlled so that the hydrofoil rotates around the rotation axis with the period of the incoming waves and so that a difference between the phase of the incoming wave and a rotation angle of the hydrofoil is equal to a target difference. 2. The method of claim 1, wherein the target difference corresponds to the wave energy converter generating a wave that is 180° out of phase with the incoming wave. 3. The method of claim 1, wherein controlling the rotation angle comprises adjusting a torque that a load applies to the rotation axis, the torque being adjusted to compensate for an error between the target difference and the difference between the rotation angle and the phase of the incoming wave. 4. The method of claim 3, wherein once the difference between the rotation angle and the phase of the incoming wave matches the target difference, controlling rotation further comprises adjusting the torque that the load applies so that the hydrofoil rotates about the rotation axis with the period of the incoming waves. 5. The method of claim 1, further comprising repeating the measuring and controlling steps as at least part of a phase-lock process. 6. The method of claim 1, further comprising: measuring a height of the incoming waves;determining a target pitch angle from the height; andholding the hydrofoil at the target pitch angle as the wave energy converter rotates. 7. The method of claim 6, further comprising holding a second hydrofoil that is mounted on the wave energy converter an offset from the rotation axis at a second pitch angle as the wave energy converter rotates, wherein the second pitch angle has a magnitude equal to a magnitude of the target pitch angle and a sign opposite to that of the target pitch angle. 8. The method of claim 7, wherein the second hydrofoil is on a side of the rotation axis directly opposite to the first hydrofoil. 9. The method of claim 6, further comprising repeating the measuring, determining, and holding steps to update the target pitch as the incoming waves change. 10. The method of claim 1, further comprising: measuring a height of the incoming waves;using the height measured to determine a target offset; andadjusting the offset of the hydrofoil from the rotation axis to match the target offset. 11. The method of claim 10, wherein using the height measured to determine the target offset comprises selecting the target offset according to power in harmonic components of a wave that the wave energy converter would generate when the offset of the hydrofoil is equal to the target offset. 12. The method of claim 10, further comprising repeating the measuring, determining, and adjusting steps to update the target offset as the incoming waves changes. 13. A wave energy converter system, comprising: a sensor system positioned to measure a period and a phase of incoming waves;a main shaft;a first hydrofoil that is mounted on the main shaft at an offset, wherein a mounting of the first hydrofoil permits control of a pitch angle of the first hydrofoil; anda control system configured to control the rotation of the main shaft so that the hydrofoil rotates around a rotation axis of the main shaft with the period of the incoming waves and so that a difference between the phase of the incoming wave and a rotation angle of the first hydrofoil is equal to a target difference. 14. The system of claim 13, further comprising a load coupled to the main shaft, wherein the control system is further configured to control rotation by adjusting a torque that the load applies to the main shaft, and adjustment of the torque compensates for an error between the target difference and the difference between the rotation angle and the phase of the incoming wave at the wave energy converter. 15. The system of claim 14, wherein once the difference between the rotation angle and the phase of the incoming wave matches the target difference, the control system adjusts the torque that the load applies so that the first hydrofoil rotates about the rotation axis with the period of the incoming waves. 16. The system of claim 13, wherein: the sensor system is configured to measure a height of the incoming waves; andthe control system is further configured to use the height in determining a target pitch angle and to control the pitch of the first hydrofoil so that the pitch of the first hydrofoil remains at the target pitch as the main shaft rotates. 17. The system of claim 16, further comprising a second hydrofoil that is mounted on the main shaft at an offset, wherein the second hydrofoil is on a side of the main shaft opposite from the first hydrofoil, and a mounting of the second hydrofoil permits control of a pitch angle of the second hydrofoil. 18. The system of claim 17, wherein the control system is further configured to control the pitch of the second hydrofoil so that the pitch of the second hydrofoil is opposite to the pitch of the first hydrofoil. 19. The system of claim 17, wherein twice the offset of the first hydrofoil from the main shaft is between 0.15 and 1.0 times a wavelength of the incoming waves. 20. The system of claim 13, wherein: the sensor system is configured to measure a height of the incoming waves;the mounting of the first hydrofoil permits control of the offset of the first hydrofoil from the main shaft, andthe control system is configured to adjust the offset of the first hydrofoil according to the height of the incoming waves. 21. The system of claim 13, wherein twice the offset of the first hydrofoil from the main shaft is between 0.2 and 0.4 times a wavelength of the incoming waves. 22. The system of claim 14, wherein the load comprises: a mechanical transmission; andan electric generator connected through the mechanical transmission to the main shaft.