Power frequency inverter power first inverter DC into power frequency low-voltage AC; Then through the power frequency transformer to 220V, 50Hz AC power for load use. Its advantage is that the structure is simple, and various protection functions can be realized at a lower voltage. Because there is a power frequency transformer between the inverter power supply and the load, the inverter power supply runs stably, reliably, has strong overload capacity and shock resistance, and can suppress the high-order harmonic components in the waveform. However, the power frequency transformer also has the problem of heavy and high price, and its efficiency is also relatively low.

According to the current level of production of small power frequency inverter power supply, its rated load efficiency is generally not more than 90%, and because the power frequency transformer in the full load and light load when the iron loss is basically unchanged, so that it is running under light load no-load loss is larger, the efficiency is also low.

High-frequency inverter power supply first through high-frequency DC/DC conversion technology, the low-voltage direct current inverter into high-frequency low-voltage AC; Then after the high frequency transformer boost, and then through the high frequency rectifier filter circuit rectifying into high voltage direct current usually above 300V;

Finally, through the power frequency inverter circuit, 220V power frequency AC power is obtained for load use. Because the high-frequency inverter adopts a small size and light weight high-frequency magnetic core material, the power density of the circuit is greatly improved, so that the no-load loss of the inverter is very small, and the inverter efficiency is improved. Usually, high frequency inverter power supply used in small and medium-sized PVS, its peak conversion efficiency can reach more than 90%.