A DFIG wind turbine ride‐through system. Influence on the energy production

Abstract

The influence of a voltage sag ride-through system on the energy production of a doublyfed induction generator (DFIG) wind turbine is investigated. Using simulations, a candidate ride-through system based on insulated gate bipolar transistor (IGBT) modules with high current rating and with the option of having antiparallel thyristors, which can quickly disconnect the stator of the DFIG from the grid, is developed.It has been found that, by increasing the current rating of the converter IGBTs, the losses of the converter can be reduced. However, if antiparallel thyristors have to be connected between the stator and the grid in order to achieve a fast disconnection of the stator circuit, the overall losses of the total system increase instead.

Summary on Voltage Stability of Power Grid in Large-scale Wind Power Area

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Protective strategy of Crowbar circuit when network voltage drop sharply

“…Because after the elimination of the fault, the grid voltage from the voltage fault return to the normal voltage last for a brief time, the transient current generated in the stator side of the doubly fed induction generator is very large. Anti parallel power electronic devices of the circuit can rise the stator side voltage which will reduce the transient current generated by the stator [8] .…”

Control strategy for the rotor side converter of a DFIG-WT under balanced voltage sag

“…Assuming that the current control of the converter is fast and accurate, so that the currents of the rotor track the references given in (10) and (11), then (5) and (6) results in (12) and (13) …”