Fault-tolerant control of a PMSG-based wind turbine based on parallel interleaved converters

Abstract

Lowering the cost of wind energy has been one of the main objectives of the wind industry in the past years.To achieve this objective, considerable research efforts have been made to improve the availability of wind turbines.Recent statistical analyses have shown that frequency converters are among the most frequently failing components forvariable speed wind systems. Therefore, several configurations were proposed in the literature to improve the availabilityof these generating devices. These configurations are mainly based on the redundancy of power converters (active andstandby) or the converter bypass technique. However, for the special case of PMSG-based wind turbines, the powerelectronic subsystem cannot be bypassed and redundancy will significantly increase the cost of the overall structure sincefully rated converters are used. Therefore, this paper proposes a new design for PMSG-based wind turbines based onparallel interleaved converters and a fault-tolerant control strategy. In the proposed configuration, the generator-sideand the grid-side converters are made with two parallel interleaved converters with separate DC links. The design isintended to offer continuity of service in the event of converter failure with low additional costs. The design, simulation,and advantages of the proposed configuration are detailed throughout the paper.