Inverter is a kind of transformer converting the low-voltage DC power (usually such as the power output by the battery) into the high-voltage AC high-frequency power (sine wave AC power of 220V 50Hz or 110V 60Hz). Take a 12V DC to 220V AC car power inverter as example to illustrate the working principle briefly. Firstly, the 12V low-voltage DC power in the vehicle is converted into the high-voltage DC power of around 265V, and then the 265V DC power is converted into the sine wave AC power of 220V, 50Hz. The main inner components of power inverter include the Inverter Bridge, filter circuit, oscillator, control logic circuit and so on. At present, a large amount of various power inverters are filled in various e-commerce platforms. The cheapest one is only tens of dollars, but the expensive ones can cost several hundreds or even one thousand dollars. The maximum power it sustains range from dozens of wattages to several hundreds of wattages. Then, what kind of power inverter can we choose?