Fault Ride-Through Analysis and Protection of a 2-MW DFIG Tidal Current Turbine

Abstract

A B S T R A C TThe purposes of this article are to report on a study of fault ride-through (FRT) capability improvements of a tidal current turbine with a doubly fed induction generator (DFIG) and to investigate protection schemes for power electronic converters without disconnection during grid faults. A dynamic model of a DFIG tidal current turbine is described in the article, taking into account the effect of crowbar protection on the system when subjected to disturbances, such as short circuit faults. Investigations into the dynamic behavior of tidal current turbines are made through extensive simulations via PSCAD/EMTDC software. The research demonstrates that both the timing of crowbar removal and the value of crowbar resistance have a significant impact on the system voltage recovery following grid faults. The article also demonstrates that the selection of an appropriate crowbar resistor value is critical in order to ensure that the DFIG returns to normal operation with active and reactive power control as quickly as possible.

Effect of Doubly Fed Induction GeneratorTidal Current Turbines on Stability of a Distribution Grid under Unbalanced Voltage Conditions

“…Many tidal current turbines are connected in a distribution grid where asymmetrical loads, asymmetrical transformer windings or transmission impedance and transient faults (voltage dip) will be the typical sources of the problem, resulting in unbalanced operations [3,4]. The doubly fed induction generator (DFIG), as the most popular form of tidal current energy generation [5], is very sensitive to unbalanced operation of a grid due to its direct coupling to the grid [6,7].…”