Optimization of a Direct Drive Active Heave Compensator

Heave compensation systems enable vertically tethered systems to operate in dynamic sea states. Both passive and active systems can be implemented to reduce tether tension fluctuations and submerged equipment oscillations. This paper presents work completed on the analysis of a winch-controlled active heave compensator for a vertically tethered system. Simulation-based design methods were used to evaluate the heave compensation given the complete nonlinear coupling between environment, tether, and winch behavior. The analysis provides insight on the controller gain values and power requirements of the winch to operate in a variety of system configurations and sea state conditions. In addition, the benefit of a passive compensator system coupled to the active system highlights the potential utility of a hybrid heave compensator system.