AC/DC in PV: Inverters and Power Conversion - Summary
Solar cells generate direct current (DC), but household appliances require alternating current (AC) at 50 Hz. The inverter bridges this gap.
DC vs. AC
| Type | Characteristics | Examples |
|---|---|---|
| DC (Direct Current) | Current flows continuously in one direction | Batteries, solar cells, USB devices |
| AC (Alternating Current) | Current direction changes constantly (50× per second) | European power grid, household outlets |
The Inverter: Heart of Power Conversion
The inverter converts DC from solar modules into grid-compliant AC through electronic switches (IGBTs or MOSFETs):
- DC Input: Direct current from modules
- Chopping: Power switches rapidly turn DC on and off
- Filtering: Smoothing to create a clean sine wave
- AC Output: Grid-compliant 230V/400V alternating current
Single-Phase vs. Three-Phase Systems
| System | Power | Application |
|---|---|---|
| Single-phase | Up to 4.6 kVA | Small systems, balcony power plants |
| Three-phase | Above 4.6 kVA | Larger roof systems, commercial |