I recently came across the seminal work on "Negative-sequence current injection for fast islanding detection of a distributed resource unit". The paper says "The RLC load tank draws the rated, positive-sequence fundamental current component supplied by VSC at unity power factor. If a 60 Hz negative-sequence current component is also injected by the converter current controller, it flows into the grid through the low-impedance path provided by the stiff utility grid".

Why does the grid have a relatively larger positive sequence impedance than the negative sequence impedance? (Since the load draws positive sequence current and not the negative sequence current, even though the positive and negative sequence impedances are the same for the static RLC load)

Thanks,

Mayank