Reconfigurable Control for Fault-Tolerant of Parallel Converters in PMSG Wind Energy Conversion System

摘要

Offshore wind energy conversion system (WECS) usually adopts parallel converters to expand power capacity and improve reliability because of limited power rating of power devices, harsh marine environment, and poor maintenance accessibility. Any faulty converter is cutoff under traditional fault-tolerant control. When all parallel converters are faulty, the wind turbine must be shut down. Although simple, such a fault-tolerant control reduces system availability. Thus, a reconfigurable control for fault-tolerant of parallel wind power converters is proposed in this paper. The current reference of every phase leg in parallel converter system is reconfigured postfault according to their healthy states. The proposed reconfigurable control is realized in software level and without requiring redundant hardware. Compared with traditional fault-tolerant control, the proposed reconfigurable control only cuts off the faulty legs rather than faulty converter, and makes full use of all healthy legs. The reconfigurable control improves the availability of parallel wind power converters and provides multiple-leg fault ride-through capability to WECS, enhancing reliability and electricity generation. The simulation and experimental results validate the feasibility and effectiveness of the proposed reconfigurable control.