Milestone map
Milestone map
3 milestones
Define the Power System and Model Single-Line Diagram
1–2 weeks (3–4 hrs/week)
Choose a power system to analyse — a distribution network, industrial plant power system, or microgrid. Draw a single-line diagram (SLD) showing all generation sources, transformers, busbars, transmission lines, loads, and protection devices. Assign per-unit (p.u.) base values for the system. A correctly drawn SLD with consistent per-unit bases is the foundation for all subsequent load flow and fault analysis — errors at this stage cascade through every calculation.
Proof required
Submit your system definition: a drawn single-line diagram with all components labelled, per-unit base values stated (MVA base and kV base for each voltage level), and a component list table (generation, transformer, line, load ratings).
What gets checked
- SLD labels all components with their ratings — transformer MVA/kV, line impedance, generator MVA, load MW/Mvar
- Per-unit base values are stated for all voltage levels in the system (MVA base + kV base → impedance base for each level)
- SLD is drawn (not copied from a textbook) with a consistent set of symbols
Common mistakes
- Using inconsistent base values across voltage levels — per-unit impedances will be wrong if the kV base is not correctly transformed through each transformer
- Omitting protection devices from the SLD — short-circuit analysis in M2 requires knowing where fuses, breakers, and relays are located
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm SLD labels all components with their rated values — flag any component shown without a rating.
- Confirm per-unit base values are stated for every voltage level — confirm kV base changes correctly at each transformer.
- Confirm SLD is original (not copied from a textbook) — components should match the system selected.
Perform Load Flow and Short-Circuit Analysis
3–4 weeks (4–5 hrs/week)
Perform a load flow (power flow) analysis to find bus voltages, real and reactive power flows, and transmission losses under normal operating conditions. Use Gauss-Seidel, Newton-Raphson, or a free simulation tool (PSCAD, pandapower, or PyPSA). Then perform a three-phase balanced fault (short-circuit) analysis at ≥2 buses to find fault current magnitudes and confirm protection device ratings are adequate. Both analyses are required — load flow shows normal operation; fault analysis governs protection design.
Proof required
Submit your analysis results: load flow bus voltage table and power flow summary, and fault current calculations at ≥2 buses showing method and per-unit impedance values used.
What gets checked
- Load flow results show bus voltages within ±5% of nominal — state any buses that violate this and explain why
- Fault current calculations show per-unit impedance values and base conversion — not just final kA results
- Analysis covers both normal (load flow) and fault conditions — not one or the other
Common mistakes
- Running a simulation without understanding what it calculates — verify one result by hand before trusting simulation outputs
- Fault analysis at only one bus — at minimum analyse the highest-fault-current bus (usually closest to generation) and a remote bus
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Confirm load flow results include bus voltage magnitudes and angles, plus real/reactive power flow on each line.
- Confirm at least one result is verified by hand calculation or against a textbook example — not purely simulation output.
- Confirm fault current calculations show per-unit impedance values and base conversion to physical kA.
Assess Protection Coordination and Write the Analysis Report
3–4 weeks (2–3 hrs/week)
Using the fault current results from M2, check that protection devices (fuses, circuit breakers, relays) are correctly coordinated: the device closest to the fault operates first, and upstream devices operate only if the downstream device fails. Document the time-current characteristics of each device and the selectivity margins. Write a complete power systems analysis report and have it reviewed by an electrical engineer with power systems experience.
Proof required
Submit your protection coordination assessment (time-current characteristic plot for ≥2 protection devices showing selectivity) and power systems analysis report (≥2,000 words including SLD, load flow results, fault analysis, and protection coordination) plus review record.
What gets checked
- Time-current characteristic plot shows ≥2 devices with selectivity margins labelled — not just a list of device ratings
- Report covers all four sections: SLD, load flow, fault analysis, protection coordination
- Reviewer has electrical engineering (power systems) background — peer review without domain expertise does not count
Common mistakes
- Describing protection devices without drawing their time-current characteristics — selectivity can only be confirmed visually from the curves, not from ratings alone
- Writing a report that presents only simulation outputs without interpretation — analysis means explaining what the results mean for the design
Resources
Foundationstart here
Depthgo deeper
What a verifier looks for
- Engineering Design Triad check: M1–M3 together produce a design artifact (SLD with per-unit system), an analysis artifact (load flow + fault current calculations + protection coordination plot), and a documentation artifact (complete power systems analysis report + review record) — confirm all three types are present.
- Confirm time-current characteristic plot shows ≥2 devices with selectivity margins — not just device ratings in a table.
- Confirm load flow and fault analysis results are interpreted — not just simulation outputs pasted into a report.
- Confirm reviewer has power systems electrical engineering experience — challenge questions must probe the load flow results and protection coordination logic.
- The Proof Accessibility Rule applies — pandapower (free), PyPSA (free), PSCAD free educational version, MIT OCW (free), and Schneider free guides are all accessible without commercial licence.