How are solar inverters classified?

There are many types of inverters which can be categorised in different ways.
According to the number of phases of the inverter output alternating current, it can be divided into single-phase inverter, three-phase inverter and multi-phase inverter.
According to the different working frequency of inverter inverter conversion circuit, it can be divided into industrial frequency inverter, medium frequency inverter and high frequency inverter.
According to the different waveforms of the output voltage of the inverter, it can be divided into square wave inverter, step wave inverter and sine wave inverter.
According to the different inverter line principle, it can be divided into self-excited oscillating inverter, step wave superposition inverter, pulse width modulation inverter and harmonic oscillation inverter.

According to the different structure of the main circuit of the inverter, it can be divided into single-ended inverter structure, half-bridge inverter structure, full-bridge inverter structure, push-pull inverter structure, multilevel inverter structure, forward inverter structure and flyback inverter structure. Among them, small power inverters mostly adopt single-ended inverter structure, forward inverter structure and flyback inverter structure, medium power inverters mostly adopt half-bridge inverter structure, full-bridge inverter structure, etc., and high-voltage high-power inverters mostly adopt push-pull inverter structure and multilevel inverter structure.
According to the different output power size of the inverter, it can be divided into small power inverter (<5kW), medium power inverter (5-50kW), and high power inverter (>50kW).

According to the different ways of inverter isolation (conversion), it can be divided into the way with industrial frequency isolation transformer, the way with high-frequency isolation transformer, the way without isolation transformer and so on.
According to the different directions of the output energy of the inverter, it can be divided into active inverter and passive inverter. For solar photovoltaic power generation systems, active inverters are required in grid-connected photovoltaic power generation systems, while passive inverters are required in off-grid stand-alone photovoltaic power generation systems.
In solar PV power generation systems can also be classified into off-grid inverters (inverters applied in stand-alone PV systems) and grid-connected inverters.
In grid-connected inverters, they can be divided into centralised inverters, string inverters, micro (module) inverters, bi-directional energy storage inverters and so on, according to the different ways of accessing PV modules or arrays.