An optimal power flow based control scheme is proposed in order to minimize the losses in multi-terminal HVDC systems for large offshore wind power plants. The scheme optimizes system power flows while delivering the generated wind power to the terrestrial AC grid (or grids). The proposed scheme is compared to droop control schemes in two case studies in order to illustrate the power loss reduction achieved. Dynamic simulations have been provided in order to show the dynamic behavior of both the controller and the robust operation for wind speed changes and when a communication fault occurs.