Research Objective
To design and validate a grid-forming single-phase H-bridge inverter that behaves like a virtual synchronous machine during islanded load changes and weak-grid voltage disturbances.
System Architecture
The simulation includes a DC source, H-bridge PWM inverter, LCL or LC filter, single-phase load, voltage-current sensing, virtual oscillator or VSM controller, droop loops and virtual impedance for stable grid-forming operation.
Simulation Methodology
The inverter is tested under reference voltage changes, load steps and islanded operation. The VSM and virtual inertia loops are tuned to reduce overshoot, improve voltage tracking and emulate inertia support without using a mechanical machine.
Validation Scenarios
- Steady-state voltage and current waveform verification
- Load step response under islanded operation
- Virtual inertia and damping sensitivity study
- THD and filter-performance comparison
- Controller response during DC-link or load disturbance
Expected Graphs and Result Discussion
A complete result section should include the main waveforms, controller response, operating status and comparison tables needed for engineering thesis documentation. For this project, the important graph set includes:
- Output voltage and current
- RMS voltage regulation
- Frequency deviation and virtual inertia response
- Active/reactive power sharing trend
- PWM and filter current waveform
Thesis and Research Extension Ideas
The project can be extended with adaptive VSM tuning, neural-network droop optimization, fault-tolerant PWM, hardware-in-loop readiness and SCI paper style result comparison.