HVDC converter fault ride-through simulation
A completed MMC-HVDC simulation study comparing DC-fault current, voltage ride-through, interruption, energy, and recovery across four protection strategies.

Project definition
Problem statement
A DC fault in a voltage-sourced HVDC link can draw energy from terminal capacitance, cable inductance, converters, and connected sources without the natural current zero available in an AC system.
The engineering problem is to compare converter blocking, breaker isolation, current limiting, protection timing, and controlled restoration without presenting a reduced model as equipment evidence.
Project objectives
- Build a physically interpretable 320 kV, 500 MW reduced-order MMC-HVDC model.
- Compare four protection strategies under four fault and DC-grid conditions.
- Measure peak current, voltage depression, overvoltage, fault-path energy, breaker-path energy, interruption, and recovery.
- Test sensitivity to detection and breaker timing.
- Verify the numerical result with a half-step convergence comparison and automated tests.
Project structure
Project components
HVDC model
Represents three DC voltages, two cable currents, converter-current response, voltage control, choppers, and an inductive fault path.
Protection sequence
Implements detection, current limiting, blocking, breaker opening, fault clearance, reclosing, deblocking, and recovery ramp timing.
Scenario set
Defines solid, resistive, delayed-clearance, and weak DC-grid cases with documented assumptions.
Metrics
Calculates current, voltage, energy, interruption, recovery, and transparent study-limit outcomes.
Experiment runner
Produces the 16-case matrix, complete traces, timing sensitivity, convergence evidence, and labelled figures.
Methodology
Project workflow
- 01Select the fault
Choose one prepared fault resistance, duration, and DC-grid condition.
- 02Select protection
Run the unprotected, blocking, breaker, or coordinated sequence.
- 03Solve the states
The fixed-step solver calculates voltage, line current, converter current, fault current, and mode transitions.
- 04Measure the response
Exact metrics are calculated from the complete trajectory and checked against declared study limits.
- 05Compare and verify
CSV, JSON, figures, timing sensitivity, tests, and convergence evidence support the final conclusion.
Demonstration scenario
A solid midpoint DC fault begins at 50 ms. The coordinated strategy detects it, limits converter current, blocks the half-bridge path, opens the breaker, waits for clearance, recloses, and restores power gradually. The result is compared with unprotected, blocking-only, and breaker-only cases using exact current, voltage, energy, interruption, and recovery metrics.
Engineering
Tools and method
- Tools
- The project uses Python, NumPy, Matplotlib, Jupyter for subject analysis, simulation, and results.
- Numerical model
- Python and NumPy implement the nine-state averaged DC-side equations and deterministic RK4 solver.
- Protection logic
- Immutable settings and explicit state timelines keep every intervention time visible and testable.
- Analysis
- Deterministic functions calculate current, voltage, energy, interruption, recovery, and pass or fail results.
- Figures
- Matplotlib produces architecture, waveform, metric, and sensitivity figures from the retained matrix.
- Verification
- Analytical initialization, 141 tests, 99 percent coverage, source checks, dependency audit, and half-step convergence support the release.
Testing
Evaluation
Evaluation measures
- Peak line and converter current normalized to rated DC current
- Minimum sending and receiving voltage during the fault
- Post-fault peak voltage and sustained recovery time
- Fault-path input energy and equivalent breaker-path absorbed energy
- Interruption time for breaker strategies
- Sensitivity to fault resistance, clearance duration, DC-grid strength, detection delay, and breaker operating time
Project boundaries
- The project is a reduced-order averaged DC-side teaching model and not a switching or electromagnetic transient model.
- It does not calculate individual submodule, semiconductor, AC-network, travelling-wave, or detailed breaker behaviour.
- The prepared limits are transparent comparison criteria and not equipment ratings or statutory thresholds.
- The package runs offline and must not be connected to live electrical equipment or used as protection settings.
Included
- 01Reduced-order two-terminal MMC-HVDC model
- 02Unprotected, half-bridge blocking, DC-breaker, and coordinated protection strategies
- 03Solid, resistive, delayed-clearance, and weak DC-grid scenarios
- 04Sixteen complete traces with CSV and JSON results
- 05Protection-timing sensitivity and time-step convergence studies
- 06Ten generated result figures and 50 annotated references
- 07141 automated tests with 99 percent statement coverage
- 08Complete project files, models, calculations, and analysis material in a private GitHub repository
- 09Complete project documentation in PDF and editable Word formats
- 10Setup and usage guide in PDF and editable Word formats
Project record
No information is collected on this page.
- Permanent project ID
- GP-EE-0S0C6HM
- Catalogued
- 21 Aug 2026
- Completed
- 25 Aug 2026
- Verified
- 25 Aug 2026
- Demonstration
- Included in repository
Handover
After purchase
- 01Payment is confirmed
The project is marked unavailable and cannot be purchased again.
- 02Repository access is granted
The buyer's submitted GitHub account receives access to the private repository.
- 03The purchase record is delivered
The certification sheet is prepared from the reviewed buyer details and sent privately by email.