There are two main types of inverters, one is sine wave inverter, and the other is square wave inverter. The output of the sine wave inverter is the same or better sine wave AC power as the grid we use daily, because it does not have electromagnetic pollution in the grid. The output of the square wave inverter is poor quality square wave alternating current, and its maximum value in the positive direction to the maximum value in the negative direction are generated almost at the same time, which will cause severe and unstable effects on the load and the inverter itself. At the same time, its load capacity is poor, only 40-60% of the rated load, and it cannot carry inductive load (see the next article for detailed explanation). If the load is too large, the third harmonic component contained in the square wave current will increase the capacitive current flowing into the load, which will damage the power filter capacitor of the load in severe cases. In response to the above shortcomings, quasi-sine wave (or improved sine wave, modified sine wave, analog sine wave, etc.) inverters have appeared in recent years. There is a time between the output waveform from the positive maximum to the negative maximum. Interval, the use effect has been improved, but the waveform of the quasi-sine wave is still composed of polyline, which belongs to the category of square wave, and the continuity is not good. All in all, sine wave inverters provide high-quality alternating current, which can drive any kind of load, but the technical requirements and costs are high. Quasi-sine wave inverters can meet most of our electricity needs, with high efficiency, low noise, and moderate price, so they have become mainstream products in the market. The production of square wave inverter adopts simple multivibrator. Its technology belongs to the level of the 1950s and will gradually withdraw from the market.

Inverters are divided into coal power inverters, solar inverters, wind power inverters, and nuclear power inverters according to different power sources. According to different uses, it is divided into independent control inverter and grid-connected inverter.