Triangular ripple
The unit test verifies the implemented Ipp / (8 f C) relationship.
Focused child case · power electronics · verified 28 July 2026
Make the DC-link assumption visible before selecting hardware.
Two inspectable relationships estimate voltage ripple for an ideal triangular capacitor-current waveform and minimum capacitance for a defined constant-power energy pulse.
Engineering question
What capacitance follows from the stated waveform or energy window?
These are first-pass checks for exposing current, frequency, energy, bus-voltage, and allowable-drop assumptions before switching, lifetime, thermal, tolerance, and component studies.
Explanatory architecture
Source, capacitor, converter, and load define the boundary; waveform and voltage-window assumptions determine which relationship applies.
Energy-pulse relationship
Cmin = 2E / (V₁² − V₂²)
A transparent check—not a component selection.
The companion ripple relationship assumes a zero-mean triangular capacitor-current waveform: ΔVpp = Ipp / (8 f C).
Verified result
Inputs, units, and sensitivities stay on the figure.
Ripple and energy-pulse sensitivity
The figure states 20 App at 10 kHz and a 20 kW, 20 ms pulse at 800 V. It is generated from the pinned Python relationships, not manually invented data.
- Source
- Commit 7d9f61f1ebdc · generated 28 July 2026
- Command
python scripts/generate-open-engineering-figures.py --sources-root <audit-root>
Validation and evidence
Three automated checks cover the released DC-link relationships.
Energy pulse
A valid constant-power pulse produces positive capacitance from the exact capacitor-energy change.
Invalid voltage window
The implementation rejects an allowed drop that equals or exceeds the initial bus voltage.
Parity boundary
MATLAB equivalents are present. The automated six-test repository count comes from the Python suite across thermal and DC-link families.
Reproduction path
Run the audited commit.
git clone https://github.com/mohammadrezwankhan/battery-power-models.git
cd battery-power-models
git checkout 7d9f61f1ebdca73f9facce5129f79805b1747ed0
python src/dc_link.py
python -m unittest discover -s tests -vEngineering boundary
Replace idealized inputs before making a component decision.
- The ripple relationship assumes an ideal zero-mean triangular capacitor current at one stated frequency.
- The energy-pulse relationship assumes a constant-power pulse and an exact capacitor-energy window.
- ESR, ESL, RMS heating, switching harmonics, controller interaction, voltage dependence, tolerance, temperature, aging, reliability, packaging, fault behavior, and derating are omitted.
- Use manufacturer data, mission profiles, stability studies, thermal analysis, lifetime calculations, and hardware validation before selecting a capacitor bank.
Parent and related context
Keep the child case attached to its repository.
Use the relationships to expose assumptions, not to skip detailed design evidence.Return to parent overviewOpen pinned repository