A Non-Redundant Fault-Tolerant Control of Parallel Wind Power Conversion Systems

Owing to the extreme offshore environment and high maintenance costs, offshore wind power conversion systems typically adopt a parallel topology structure to enhance power capacity. However, in conventional control schemes, the offshore wind power conversion system lacks fault tolerance. Once a converter fails, the system will immediately disconnect the whole converter. And if all parallel converters fail, the wind turbine will be shut down. In this paper, a non-redundant fault-tolerant control method is proposed for parallel wind power conversion systems. The method does not require additional redundant hardware and just modify control instructions according to grid-side three-phase current flows. With this strategy, only faulty switches need to be disconnected while all healthy switches can still be fully utilized to improve efficiency and feasibility. The proposed method is confirmed via simulation data.