The general photovoltaic power generation system that inputs DC voltage and inverter main circuit is solar cell square array DC, so the input circuit should include corresponding filter circuit and EMI circuit, and the output circuit also usually includes content filter and EMI circuit to reduce the load effect caused by ripple of inverter circuit.  The control pulse control circuit is used to generate a system to control the turn-on and turn-off of the power switch tube and to complete the function of the inverter together with the inverter circuit.  The functional diagram of the auxiliary circuit is that the input voltage of the inverter is required by the DC voltage control circuit, usually one or several DC/DC conversion circuits.  The protection circuit includes input fur (output) and output overvoltage and undervoltage protection, overload protection, overcurrent protection and short circuit protection circuit, and overheat protection, etc.

In addition, the principle of inverter is the most important in the inverter's main circuit diagram.  The main circuit of the inverter is composed of inverter power switching devices, such as switching circuits, which are generally divided into two types: isolation from isolation.  These parts form a whole inverter circuit. The actual circuit is an inverter controlled intelligently by various electronic components, such as the main circuit of the inverter is generally composed of power switching devices, and the control circuit is generally composed of microprocessor or DSP devices.  In photovoltaic inverter circuit, the main circuit topology mostly adopts triple circuit structure, namely DC-AC-DC-AC.