A METHOD OF CONTROLLING OPERATING DEPTH OF A DEVICE

摘要

A method is described of controlling a tethered, underwater, water current-driven turbine, power-generating device. A predetermined maximum depth and a predetermined minimum depth are set. In response to sensing depth of the device, an ascend protocol or a descend protocol is selectively invoked. These protocols maintain an operating depth of the device that is midway between the predetermined maximum depth and the predetermined minimum depth. The turbine includes variable-pitch rotor blades. A maximum allowable drag force load on the turbine rotors is selected. The pitch of the variable-pitch rotor blades on the turbine is adjusted such that the drag force loading of the device does not exceed a maximum design level.