Invertteri

Invertteri, the Finnish term for inverter, is an electrical device that converts direct current (DC) to alternating current (AC). It uses power-electronic switches, control electronics, and filters to synthesize AC from DC sources such as batteries or solar panels. Inverters enable the use of DC energy in homes, on the grid, or in motor drives.

Output waveforms range from square to true sine wave. Modern inverters commonly provide true sine-wave output via pulse-width modulation and filtering. Configurations include standalone/off-grid inverters, grid-tied inverters, and microinverters that attach to individual solar modules, as well as central inverters used in large installations. Many include maximum power point tracking (MPPT) for PV sources.

Grid interaction and operation: Grid-tied inverters synchronize frequency and phase with the public grid and implement anti-islanding protection. In storage systems, inverters manage charging and discharge of batteries while supplying power to loads and potentially supporting grid services.

Applications include solar PV systems, battery storage, uninterruptible power supplies, and motor drives. Efficiency commonly ranges from 90% to 98%, with losses mainly from switching and filtering. Inverter safety features cover overvoltage, overcurrent, short circuit, and thermal protection; grid-connected units follow interconnection standards such as IEEE 1547 and IEC 62109/UL 1741 where applicable.