Response of wind power park modules in distribution systems to transmission network faults during reverse power flows

Penetration levels of distributed wind power park modules (WPPMs) reach such high levels in parts of the world, for example, Germany, that reverse power flows (RPFs) from distribution to transmission level occur regularly in certain areas of the power system. This study compares the impact of normal and RPFs on the network fault response of WPPMs in distribution systems that are prone to fault-induced delayed voltage recovery issues for a fault in the transmission system. The study contributes to the ongoing discussion on grid connection requirements for WPPMs and raises awareness of a prolonged low-voltage ride-through (LVRT) operation of WPPMs when these are set to ride-through faults in `blocking mode´, during which the set-points for the active and reactive currents are set to zero. For RPFs such LVRT operation causes a substantial sustained active power deficit in power system areas with high penetration of distributed WPPMs and potentially leads to a stability risk.