Inverter Types & Operation
String inverters, microinverters, DC optimizers, bimodal/hybrid inverters, AC coupling, efficiency, and monitoring.
- Describe string inverter operation and typical residential AC output
- Compare microinverters and DC-to-DC optimizers
- Explain hybrid, bimodal, and AC-coupled system architectures
- Describe monitoring, performance metering, and data loggers
- State typical inverter efficiency values and input current limits
Lesson 1
String Inverters & Residential AC Output
What Is a String Inverter?
A string inverter converts DC power from a string of series-connected PV modules into AC power for the building or grid. It is the most common inverter type for residential and small commercial systems. One string inverter handles all modules on one or more strings.
The typical AC output voltage of a residential string inverter in the US is 240V split-phase (120/240V). This matches the standard residential service and allows the inverter to connect directly to the home's electrical panel.
Maximum Inverter Input Current
The typical maximum inverter input current is determined by the inverter's DC input specifications listed on the datasheet. Each MPPT input has a maximum current rating. Exceeding this rating by connecting too many parallel strings can damage the inverter or trigger protective shutdown.
String inverters convert DC to AC at 240V split-phase for residential use. Typical efficiency is 96 - 99%. Maximum inverter input current is listed on the datasheet and determines how many parallel strings each MPPT input can accept.