Research Objective
The objective of this project is to study battery energy-storage protection during AC-side and DC-side fault events using a research-oriented MATLAB Simulink workflow. The model can be used to demonstrate system response, controller action, disturbance handling and output interpretation for academic reports and research presentations.
Model Scope
The simulation page is structured around the practical elements required for an engineering project: source or plant model, controller design, measurement signals, disturbance cases, output graphs and comparative result discussion. The project can be extended by changing controller parameters, operating conditions, converter limits, fault levels or performance indicators.
System Architecture
The BESS protection model can be organised around a battery pack, bidirectional DC–DC converter, DC-link capacitor, grid-side inverter, AC filter, transformer or grid/load interface and measurement-based protection logic. This arrangement allows the simulation to study how storage converters behave during abnormal AC-side and DC-side conditions.
The AC side is useful for analysing grid faults, load short-circuits and voltage sag events, while the DC side is useful for observing DC-link overcurrent, battery current stress and converter interruption requirements. A clear separation of sensing, logic and isolation blocks improves the academic explanation of the protection sequence.
Fault Detection and Protection Logic
The protection section may use current thresholds, voltage thresholds, rate-of-change indicators, relay timers and latching logic. The aim is to detect the fault quickly without unnecessary tripping during normal transients.
- AC overcurrent and voltage sag detection for grid/load-side disturbances.
- DC-link undervoltage or overcurrent detection for DC-side abnormalities.
- Battery current limiting to protect the storage element.
- Trip signal generation for breaker, converter blocking or isolation command.
- Reset and restoration logic for post-fault operation.
Simulation Cases for Validation
- Normal charging/discharging operation before fault application.
- AC-side line-to-ground or three-phase fault with fault insertion and clearing time.
- DC-side short-circuit or DC-link abnormal condition.
- Converter current-limiting and trip delay sensitivity analysis.
- Post-fault recovery of DC-link voltage, battery power and grid current.
- Comparison of response with and without protection logic.
Result Interpretation
The results should explain fault detection time, peak current limitation, DC-link voltage deviation, battery current stress, breaker/trip timing and recovery behaviour. Strong graph sets include AC voltage/current, DC-link voltage, battery current, converter current, SOC, fault flag, trip command and load/grid power restoration.
Suggested Methodology
- Build the BESS model with battery, bidirectional converter, DC link, inverter and grid/load interface.
- Create AC-side and DC-side fault scenarios with controlled timing and repeatable simulation cases.
- Design threshold, logic or relay-based protection for overcurrent, undervoltage and DC-link abnormality.
- Compare protection response time, voltage recovery, current limiting and post-fault stability.
Expected Output Graphs
- AC voltage and current waveforms during grid-side faults
- DC-link voltage, battery current and converter current during DC fault cases
- Fault detection signal, trip command and isolation timing
- SOC and power recovery after fault clearance
- Comparison of normal, AC-fault and DC-fault operating conditions
Research Extensions
Advanced extensions can include comparative controller tuning, optimization-based parameter selection, robustness testing, sensitivity analysis, real-time implementation preparation and IEEE-style result discussion. For PhD work, the novelty can be framed through improved controller response, better energy management, faster disturbance rejection or more reliable protection logic depending on the project topic.