Spain, May 9, 2016 – Ingeteam announced today the introduction of its Crowbarless solution, a modular Fault Ride Through (FRT) system for power converters that will strengthen the grid compliance of Doubly fed induction generators (DFIG). Thanks to the modular FRT system, the Crowbarless solution offers superior capabilities compared to the active crowbar system traditionally used to protect the power converter from grid voltage transient.
Until recently, most grid codes allowed wind turbines to disconnect from the grid when transients in grid voltage could jeopardize the integrity of their elements, especially the power converter. Due to the ever-increasing wind power penetration around the world, this is no longer the case. Ingeteam has come up with a new way to deal with low capacity transmission lines (so-called weak grids) and fault-ride through events, to remain fully grid compliant.
“The traditional crowbar solution used in DFIG topology presents a poor response to the voltage sags. This is because, when a voltage sags appears in the stator terminal, the machine side converter is disabled until the inductor generator flux is stabilized. Thanks to new software and hardware implemented in our crowbarless solution, the machine side converter is available at all times during the voltage sag, achieving injection times required by the most restrictive grid codes,” commented Ingeteam’s R&D Director Carlos Gironés.
To date, the most widely used system to protect the power converters from voltage spikes is the so-called “active crowbar”, a shunt circuit composed of actively controlled switches and dissipation elements which are connected in order to shunt the high currents, avoiding damages to the converter. This system, however, presents the limitation that while the active crowbar is connected, the power converter is not in operation, the active and reactive power set points cannot be tracked, and therefore the wind turbine is not being controlled. Ingeteam’s Crowbarless power converter, designed to operate in DFIG topology, uses a Modular FRT system that removes the need for the active crowbar.
