The effectiveness of additional reactive current injection from a distributed energy resource unit to mitigate short voltage instability during extreme low voltage ride through

This paper examines the effectiveness of additional reactive current injection of the inverter-based distributed energy resource to mitigate short voltage instability during extreme-low voltage ride through, by studying the steady-state voltage rise effect under different X/R ratios and the effect of normal operating setting, such as unity-power factor and under-excitation. The response to the potential occurrence of interim loss-of-synchronism during a ride through due to the additional reactive current injection is also considered. By using simple phasor analysis it is shown that the impact of such current injection is likely to be less effective on low voltage and more effective on high voltage-connected distributed resources. Furthermore, the interim loss-of-synchronism during extreme-low voltage ride through is illustrated via simulations utilizing PowerFactory DIgsilent.