Inverters: single-phase, three-phase
What are inverters
A solar inverter or PV inverter, is a type of electrical converter that converts the variable DC output from a PV solar panel into an (AC) output which is at utility frequency which can be directly fed to power appliances or fed directly into the electrical grid. Solar power inverters have extra functions for optimizing the output of PV arrays, like maximum power point tracking and anti-islanding protection.
Single-phase and three-phase
Most homes usually use single-phase power supply. The three-phase power supply is usually used for industrial locations as three-phase can transfer more power and is used for powering large equipment like heaters, machines, electric car chargers, etc.
Power is usually transferred using AC (alternating current) at a frequency of 50 – 60 Hz, while single phase is not used to transfer power; this is why the transmission lines have multiples of 3 lines. For 3 phase the power is transmitted across the network using 3 different currents which are all out of “phase” with each other.
What are the main differences between single-phase and three-phase inverters?
A single phase inverter can produce single phase power from the PV modules and connect to single phase equipment or the grid. There are two types of single phase inverters which are full bridge inverter and half bridge inverter.
A three phase inverter on the other hand can produce three phase power from the PV modules and can be connected to three phase equipment or grid. A three-phase inverter converts the DC input from solar panels into three-phase AC output. Its three phases are normally delayed by an angle of 120° to generate the 3-phase AC supply.
Usually a three phase inverter is preferred if three phase power source is used in the installation location, single phase inverter is also used for single phase sources and is the most common of the two types.
The three-phase inverter means you can produce more power for direct use and also send much more solar energy back into the grid compared to single-phase.