Table 8.
Performance comparison of different operating cases.
| Scenario & Control mode | PCC voltage response | Reactive power (Qinv) Behavior | Active power (Pinj) Behavior | Stability/justification |
|---|---|---|---|---|
| EAPC (INC only) | Remains near nominal, no corrective action | ≈ 0 (no reactive support) | Closely follows MPPT | Stable but offers no grid-support capability |
| R-EAPC (INC + Q support) | Improved regulation, smaller deviations | Nonzero VAR injection during voltage dips | Tracks MPPT, no curtailment unless limits reached | Stable; validates benefit of reactive support |
| Oversized R-EAPC (S = 1.1×Prated) under partial shading | Voltage dip is mitigated faster due to extra headroom | Higher Q capability without sacrificing active power | Pref follows shading profile; less curtailment than Case 3 | Stable; oversizing improves Q/P balance |
| Cloud transient (irradiance drop) | PCC voltage remains regulated despite sudden P reduction | Reactive injection maintains voltage | Pinj reduces smoothly with irradiance | Stable; demonstrates robustness under solar variability |
| Voltage sag (60%) | PCC voltage supported above source sag; recovery accelerated | Significant reactive injection during sag | Active curtailed slightly during sag, restored after | Stable; meets ride-through requirement |
| Fault Ride-Through (three-phase short) | PCC voltage does not collapse fully; faster recovery after clearing | Large reactive current injected per grid code | Active curtailed strongly during fault; restored after | Stable; validates R-EAPC effectiveness under severe fault |