This project presents a low-power laboratory model of a 12v High Voltage DC (HVDC) link implemented using a single-phase inverter–rectifier system controlled by SPWM (Sinusoidal Pulse Width Modulation).
The setup demonstrates the basic operating principle of an HVDC bus, including power conversion, isolation, and gate driving, suitable for educational and prototyping purposes.
The implemented system consists of:
- A rectifier stage converting AC to DC
- A DC-link capacitor for smoothing and energy storage
- A single-phase inverter stage controlled using SPWM
- Optical isolation for safe gate driving
- Frequency control can be done by changing the sineFreq in esp32 code.
The inverter is driven using complementary SPWM signals with dead-band insertion to prevent shoot-through.
Figure 1: Single-phase SPWM gate signals with dead-band
| Component | Description |
|---|---|
| ESP32 | PWM generation and control |
| MOSFETs (×4) | Full-bridge inverter switches |
| TLP251 | Opto-isolated gate driver |
| Resistors | Gate and signal conditioning |
| Capacitors | DC-link smoothing |
| Breadboard | Prototype assembly |
| 230v/12v step down transformer | power conversion |
| Diodes (×4) | full bridge rectifier |