Ride-through fault generalized control method for a wind turbine inverter

Abstract

The growing share of installed wind capacity in transmission systems nowadays require wind turbines to remain connected to the grid during severe network disturbances as well as to provide efficient restoration to the pre-fault conditions. It is know that grid side inverters are sensitive to voltage disturbances which results in appearance of low order harmonics in line currents as well as a huge ripple on a DC link capacitor. This paper presents a generalized method for grid-fault ride-through control for a wind turbine inverter. An analytical approach for complete harmonic elimination in grid currents and DC link voltage with controllable power factor under extreme disturbances in the power system is proposed. To illustrate the proposed method, the simulation results of a variable speed wind turbine system with PM synchronous generator under severe faults are shown and compared to the results obtained by using a standard indirect current control method.