Connection of Off-shore Wind Power Plants to VSC-MTdc networks using HVdc Diode-Rectifiers

This paper introduces the use of a diode based HVdc rectifier for the connection of a large off-shore wind power plants (WPP) to an existing multiterminal VSC-HVdc grid. Wind turbines with fully rated converters are used to control the offshore ac-grid voltage and frequency and the power delivered by the WPP. Moreover, the proposed topology allows for black-start operation of the off-shore WPP and exhibits a good response against perturbations such as off-shore faults. The technical feasibility of the proposed topology has been validated by means of detailed PSCAD simulations, assuming a WPP consisting on five aggregated wind turbines of different ratings to evaluate the distributed nature of the control strategy.