Design and laboratory test of black-start control mode for wind turbines

In this article, an operational strategy and control concept for wind turbines (WTs) are described, which would allow them to actively contribute to black‐start events after major power system outages. The approach is based on (a) a new generator/converter control strategy implementing a so called virtual synchronous machine (VSM) and (b) a number of modifications to the superimposed WT controller allowing for operation in black‐start conditions. In order to operate stably even at very low active power levels and to cope with sudden changes in active power, due to switching of loads in the recovered grid, the rotor speed/pitch controller had to be redesigned. The extension of the operational range of the WT towards negative power, ie, power consumption, is discussed, which would allow the turbine to temporarily provide a controllable minimum load to conventional power plants until a sufficient number of consumers has been reconnected. The control system has been implemented and verified using two experimental power converters, each linked to a hardware‐in‐the‐loop (HiL) simulator of a WT and connected to a real medium‐voltage laboratory grid.