PV string inverters are connected to individual PV module arrays. They are called string inverters because they are connected to a ‘string’ of PV modules connected in series. Some can be connected to several strings and are called multi-string inverters. They convert the direct current (DC) electricity from the PV modules into alternating current (AC) electricity.
PV inverter connected to a ‘string’ of PV modules.
Larger solar systems will have several of these inverters. Some models produce 3-phase AC electricity.
Large PV system with several string inverters.
String inverters are used in grid-connected residential systems, in larger non-residential/commercial buildings, and in ‘off-grid’ AC mini-grids. They can also be used in larger solar power plants.
Power ratings of string inverters usually range from 1 kW to over 50 kW for multi-string inverters, but there are some larger models on the market.