Don Nelson · May 6, 2026 · DIgSILENT PowerFactory · 10/10 scenarios converged
Generation figures correspond to the PowerFactory run on CEN's database, expressed as gen without SAE (thermal + hydro + solar + wind), validated against the official PDF within ±1-2%. BESS is reported separately.
This study analyzes the steady-state power flows of Chile's National Electric System (SEN) over the April 2026 operation database published by the National Electric Coordinator (CEN). It will assess weekday, Saturday, and Sunday conditions across three time blocks — day, evening, and early morning — plus a maximum joint renewable penetration scenario (NCRE CC).
The input data comes from the operation database published by CEN for April 2026 (code O-DMAP-BD-OP-COORD, project 2604-BD-OP-COORD-DMAP, final version 30-04-2026). CEN selected real instants from the SCADA state estimator within the window from March 15 to April 14, 2026: the minimum gross generation instant for early-morning blocks, and the maximum gross generation instants for day and evening. The NCRE CC instant corresponds to the maximum combined wind + solar generation percentage.
The power flows ran in DIgSILENT PowerFactory 2024 on a GCP VM. All 10 scenarios converged and the model's net generation matches CEN's official published figure within ±1-2% — see the validation sub-section below.
The gen without SAE produced by PowerFactory in each of the 10 scenarios matches the figure CEN publishes in p.2 of the PDF ("Gross generation without SAE") within a ±1-2% margin. That difference is Newton-Raphson convergence tolerance, not physical error — both engines solve the same .pfd.
| Scenario | PowerFactory (MW) | CEN p.2 (MW) | Δ (MW) | Δ % |
|---|---|---|---|---|
| Wkd. Early | 8,637 | 8,728 | -91 | -1.0% |
| Wkd. Day | 10,086 | 10,193 | -107 | -1.0% |
| Wkd. Eve. | 10,006 | 10,085 | -79 | -0.8% |
| Sat. Early | 7,918 | 8,106 | -188 | -2.3% |
| Sat. Day | 8,458 | 8,540 | -82 | -1.0% |
| Sat. Eve. | 10,010 | 10,171 | -161 | -1.6% |
| Sun. Early | 7,308 | 7,460 | -152 | -2.0% |
| Sun. Day | 9,342 | 9,433 | -91 | -1.0% |
| Sun. Eve. | 9,476 | 9,636 | -160 | -1.7% |
| NCRE CC | 7,632 | 7,682 | -50 | -0.7% |
CEN selected 10 real SCADA instants and modeled them in the DB. Don Nelson ran the power flow (balanced Newton-Raphson) on all 10 scenarios — every one converged. Values shown in the table and figures below are gen without SAE (thermal + hydro + solar + wind) as reported by PowerFactory.
Weekday day on April 10 consolidates 10,086 MW with an unusually balanced mix (38.1% solar and 37.5% thermal simultaneously), while BESS absorbs 880 MW to dampen solar oversupply. At the other extreme, Sunday early morning on April 5 marks 7,308 MW. The NCRE CC scenario consolidates 7,632 MW with 54.3% solar over the lowest inertia of the month (34.7 GVAs) — a fragility point for stability analysis.
| Day | Eve. | Early | |
|---|---|---|---|
| Weekday | |||
| Saturday | |||
| Sunday |
| Scenario | Date | Gen w/o SAE | Inertia | Hydro % | Therm % | Solar % | Wind % |
|---|---|---|---|---|---|---|---|
| Wkd. Day | 10-04-2026 | 10,086 | 50.9 | 15.6% | 37.5% | 38.1% | 8.8% |
| Wkd. Eve. | 30-03-2026 | 10,006 | 53.2 | 17.6% | 49.8% | 11.5% | 20.5% |
| Wkd. Early | 13-04-2026 | 8,637 | 50.4 | 27.2% | 47.6% | 0.8% | 15.4% |
| Sat. Day | 11-04-2026 | 8,458 | 39.4 | 12.2% | 31.3% | 43.1% | 13.3% |
| Sat. Eve. | 11-04-2026 | 10,010 | 58.0 | 17.5% | 56.2% | 2.6% | 22.5% |
| Sat. Early | 04-04-2026 | 7,918 | 47.3 | 18.5% | 47.9% | 2.2% | 22.2% |
| Sun. Day | 22-03-2026 | 9,342 | 49.2 | 12.6% | 39.2% | 41.3% | 6.9% |
| Sun. Eve. | 12-04-2026 | 9,476 | 51.3 | 17.1% | 55.6% | 0.0% | 22.3% |
| Sun. Early | 05-04-2026 | 7,308 | 53.5 | 17.5% | 61.2% | 16.0% | 2.5% |
| NCRE CC | 03-04-2026 | 7,632 | 34.7 | 10.7% | 24.4% | 54.3% | 10.5% |
Technology composition of gen without SAE — thermal + hydro + solar + wind — for each of the 10 scenarios. Percentages come from the dispatch that the power flow produced when converging.
Weekday day operates at 38.1% solar and 37.5% thermal simultaneously — an unusually balanced matrix. Saturday day reaches 43% solar at 14:16 (PV peak), while Saturday evening at 18:46 is already 56% thermal. Sunday early morning hits 61% thermal, and NCRE CC marks the month's solar peak at 54% on top of the lowest inertia base (34.7 GVAs).
Per-zone data not available for NCRE CC in this run.
The most heavily loaded line in each scenario, per the power flow. Three scenarios mark loading >100% — Saturday early morning (NEGRETE-EST.187AB 152.8%), Sunday evening (same line 117.3%) and NCRE CC (91.0%). Generally the congestion concentrates on 23–66 kV lines in the country's center-south, same pattern as March.
| Escenario | Línea | Cargabilidad |
|---|---|---|
| Sat. Early | NEGRETE - EST.187AB 66KV C1 | 152.8% |
| Sun. Eve. | NEGRETE - EST.187AB 66KV C1 | 117.3% |
| Sun. Day | Colector Eq BESS Tocopilla | 98.5% |
| Sun. Early | C San Javier - Constitución 66 kV | 97.5% |
| Sat. Day | Colector Eq. PE Aurora 33 kV | 96.5% |
| Sat. Eve. | C San Javier - Constitución 66 kV | 95.0% |
| NCRE CC | NEGRETE - EST.187AB 66KV C1 | 91.0% |
| Wkd. Day | Colector Eq. PV Aguila 13.18 kV | 90.9% |
| Wkd. Early | Tap La Silla - ESO 23 kV | 89.8% |
| Wkd. Eve. | 13.8 kV PAS3-Pozo Almonte | 81.7% |
Transformer data not available for NCRE CC in this run.
CEN documents the modifications applied to the database with respect to the previous month. The most relevant for April:
These are not new plants: they are dynamic models added to the .pfd to improve simulation of the existing network.
Below are the detailed results for the weekday day scenario — the most demanding of the month, with maximum simultaneous solar generation and high thermal participation. It identifies plants with the highest dispatch, lines and transformers with the highest loading, and buses with the most compromised voltage profiles. Full data for the remaining 9 scenarios is available in the open data section.
These elements are points of attention for safe planning and operation of the system, and may require transmission reinforcements or adjustments in dispatch strategy and reactive control.
1. Historical peak dispatch. Weekday day consolidates 10,086 MW of gen without SAE in PowerFactory, with an unusually balanced mix: 38.1% solar and 37.5% thermal simultaneously. BESS absorbs 880 MW of solar oversupply at that same instant.
2. NCRE CC with minimum inertia. The scenario of maximum joint renewable penetration marks 34.7 GVAs of inertia, the month's lowest value, with 54% instant solar and BESS absorbing -871 MW. A fragility point for stability analysis.
3. Overloads on 66 kV in center-south. The NEGRETE - EST.187AB 66 kV C1 line appears as the most loaded element in three scenarios (Saturday early morning 152.8%, Sunday evening 117.3%, NCRE CC 91.0%). Same structural pattern as March, no relief.
4. Highly active BESS during daytime. In weekday day, Saturday day, Sunday day and NCRE CC, storage systems absorb between -775 and -880 MW, acting as a buffer for solar oversupply. In early mornings they inject 200-860 MW to cover the transition.
Don Nelson runs the same analysis over CEN's monthly database. The following comparison contrasts April (this study) with March 2026 — before BESS Víctor Jara, PFV Víctor Jara, BESS Arica II and the new EB3, EB4, and Traful substations were added to the network.
All power flow results are available for download in JSON format. Each file contains the complete data for buses, lines, generators, and transformers for each scenario, allowing independent verification and analysis.