PV inverters are generally divided into:
– Grid-connected inverters can be connected in parallel to the public gird
– Off-grid or island solution inverter for solar systems that draw power from a battery unit system or the public grid, but cannot feed energy into the grid the way grid inverters do.

Grid-connected Inverters
Motto Engineering is the official representative in Bulgaria for the products of the German company KACO New Energy. KACO offers a full range of units necessary for the support of solar systems for both single family houses and megawatt solar parks . Various series include :

Singlephase string inverters

Singlephase string inverters are used when single-phase gird connection is applied. Photovoltaic panels are connected in series to form strings. 02 series inverters have transformer that separates them galvanically from the network, as this is still a safety requirement in some countries.

● Powador 2002 – 6002 (transformer)

● Powador 3200 – 9600 (transformerless)

Three-phase inverters

Three-phase inverters are used when three-phase grif connection is applied. Photovoltaic panels are connected in series to form strings. TR3 series inverters have transformer that separates them galvanically from the network, as this is still a safety requirement in some countries.

● 16.0 TR3 – 18.0 TR3 (transformer)

● 6.0 TL3 – 72.0 TL3 (transformerless)

Central inverters

Central inverters are used in megawatt power plants. The lowest power of a unit in this series is 100 kW. They have an integrated intelligent power modulation (IPM) and Surge Protection.

● Powador XP

KACO quality is certified by TÜV and RAL – quality stamp for solar installations.

Off-grid Inverters

Inverters of the Dutch company Victron Energy are a tested island solution and UPS component in case of blackouts . The company has traditions in solar technologies and the main features are:

● Full Sinewave

● High efficiency and peak power

● Possibility for additional power from the grid and/or diesel generator

● Possibility for a battery charger

According to the combination of different characteristics, the inverters are divided into series:

● VIctron Phoenix

Phoenix series inverters are used for off-grid power supply with battery unit for places without electrification

● Victron Multiplus

Multiplus series inverters are used for autonomous power supply with battery unit or for UPS systems. They have a additional AC input for grid connection or diesel generator.

● Victron Quattro

Quattro series inverters are used for autonomous power supply with battery unit or for UPS systems. They have 2 additional AC inputs for grid connection and diesel generator.