Which case count as leading PF in Salient plot generator?
The load impedance is inductive and current lags behind voltage when the phase angle between voltage and current is positive.

$$ \phi = \phi_v - \phi_i &gt; 0 \rightarrow Lagging$$

The load impedance is capactive and current leads voltage when the phase angle between voltage and current is negative.

$$ \phi = \phi_v - \phi_i &lt; 0 \rightarrow Leading$$

Both cases can be correct as it depends if you've defined the rotation of your d-q plane to be clockwise or counterclockwise. As long as you're consistent you'll be fine. I've learnt it as counterclockwise. Therefore with Ef as the reference point (0°), Ia_1 is lagging Ef and leading Vt. Ia_2 is leading both Ef and Vt.

\$ Ia_1 = -30°, Ia_2 = 30°, Ef = 0°, Vt = -60° \$

\$ \phi = \phi_v - \phi_i = Ef - Ia_1 = 0° - (-30°) = 30° &gt; 0 \rightarrow Lagging \$
\$ \phi = \phi_v - \phi_i = Ef - Ia_2 = 0° - 30° = -30° &lt; 0 \rightarrow Leading \$