Photovoltaic inverter is a power adjustment device composed of semiconductor devices, which is mainly used to convert DC power into AC power. It is generally composed of a boost circuit and an inverter bridge circuit. The boost circuit boosts the DC voltage of the solar battery to the DC voltage required for inverter output control; the inverter bridge circuit converts the boosted DC voltage into an AC voltage of common frequency equivalently. The inverter is mainly composed of switching elements such as transistors. By regularly turning the switching elements on and off (ON-OFF), the DC input becomes the AC output. Of course, such an inverter output waveform simply generated by on and off loops is not practical. Generally, it is necessary to use high-frequency pulse width modulation (SPWM) to narrow the voltage width near the two ends of the sine wave, widen the voltage width in the center of the sine wave, and always make the switching element move in one direction at a certain frequency within half a cycle, thus forming A pulse train (pseudo-sine wave). The pulse wave is then passed through a simple filter to form a sine wave, which is supplied to household appliances.

The solar AC power generation system is composed of solar panels, charge controllers, inverters and batteries; the solar DC power generation system does not include inverters. The process of converting AC power into DC power is called rectification, the circuit that completes the rectification function is called a rectifier circuit, and the device that realizes the rectification process is called a rectifier or rectifier. Correspondingly, the process of converting DC power into AC power is called inverter, the circuit that completes the inverter function is called inverter circuit, and the device that realizes the inverter process is called inverter equipment or inverter.

The core of the photovoltaic inverter device is the inverter switch circuit, referred to as the inverter circuit. The circuit completes the inverter function by turning on and off the power electronic switch. The on-off of power electronic switching devices requires certain driving pulses, which may be adjusted by changing a voltage signal. Circuits that generate and condition pulses are often called control circuits or control loops. The basic structure of the inverter device, in addition to the above inverter circuit and control circuit, there are protection circuit, output circuit, input circuit, output circuit and so on.