Jaji 6.45 MWp / 10 MWh Interconnected Mini-Grid - GIS Reconstruction & ETAP Power-System Study

02 / Results & Findings

Results from the project work.

1. 01

   Reconstructed approximately 30.41 km of 11 kV network across 45 modelled line sections using GIS-supported topology development.

   Modelled result

2. 02

   Demonstrated a high-PV grid-connected operating case with approximately 6.06 MW solar generation and significant surplus export to the utility.

   Modelled result

   • Case 1 - High-PV Grid-Connected Export (opens in a new tab)
3. 03

   Established an average-PV case using six active PV inverters producing approximately 1.817 MW with near-zero active-power exchange at the grid interface.

   Modelled result

   • Case 2 - Average-PV / Near-Zero Grid Active Exchange (opens in a new tab)
4. 04

   Reduced utility reactive-power dependence using inverter reactive support and investigated the resulting voltage response.

   Modelled result

   • Case 2 - Average-PV / Near-Zero Grid Active Exchange (opens in a new tab)
5. 05

   Improved customer-side LV voltage performance through targeted distribution-transformer tap optimization rather than increasing the entire utility source voltage.

   Modelled result

   • Case 3 - Targeted Distribution Transformer Tap Optimization (opens in a new tab)
6. 06

   Demonstrated steady-state islanded operation under both PV-plus-BESS and zero-PV BESS-only conditions.

   Modelled result

   • Case 4A - Steady-State Islanded Operation: PV + BESS (opens in a new tab)
   • Case 4B - Zero-PV Islanded Operation: BESS-Only Supply (opens in a new tab)
7. 07

   Estimated approximately 2.5 hours of BESS autonomy between 80% and 20% SOC under the modelled zero-PV island load using an equivalent battery-discharge model.

   Modelled result

   • Case 4C - BESS Autonomy Under Zero-PV Islanding (opens in a new tab)
8. 08

   Completed IEC 60909 short-circuit assessment using a 100 MVA utility fault-level base assumption with 50 MVA weak-grid and 250 MVA strong-grid sensitivity cases.

   Modelled result

   • Case 5A - Grid-Connected IEC 60909 Short-Circuit Assessment - 100 MVA Base Case (opens in a new tab)
   • Case 5B-1 - Grid-Strength Sensitivity - 50 MVA Weak Grid (opens in a new tab)
   • Case 5B-3 - Grid-Strength Sensitivity - 250 MVA Strong Grid (opens in a new tab)
9. 09

   Quantified grid-strength dependence at the 11 kV PCC, where three-phase fault current increased from approximately 2.97 kA under the 50 MVA case to 13.44 kA under the 250 MVA case.

   Modelled result

   • Case 5B-1 - Grid-Strength Sensitivity - 50 MVA Weak Grid (opens in a new tab)
   • Case 5B-3 - Grid-Strength Sensitivity - 250 MVA Strong Grid (opens in a new tab)
10. 10

    Assessed hybrid islanded short-circuit performance with PV, BESS and one 2.5 MVA diesel generator; the model indicated no effective 11 kV zero-sequence source path for single-line-to-ground faults under the configured grounding arrangement, requiring field verification before protection decisions.

    Modelled result

    • Case 5C - Islanded Short-Circuit Assessment - PV + BESS + 1 x 2.5 MVA Diesel (opens in a new tab)
11. 11

    Verified the modelled 11 kV PCC breaker remained within its stated interrupting, making and one-second thermal capabilities under the assumed 250 MVA strong-grid screening case.

    Modelled result

    • Case 5D - Worst-Case Device Duty Screening - 250 MVA Strong Grid (opens in a new tab)