The operation of an inverter can be divided into three main stages: the input stage, the intermediate circuit stage, and the output stage.
Input Stage
In the input stage, the inverter receives input current from a DC power source. This is typically DC power provided by solar panels, batteries, or other DC power sources. The input current first passes through a protection circuit to ensure the safe operation of the inverter and other devices. Then, the current enters a rectifier, which converts the DC power into a pulsed current of fixed amplitude.
Intermediate Circuit Stage
In the intermediate circuit stage, the pulsed current is processed by a capacitor filter to smooth the current waveform and reduce noise. Next, the current enters a circuit called the "inverter bridge." The inverter bridge consists of four switching devices (typically transistors or diodes). By controlling the on/off states of these switching devices, the inverter bridge can precisely adjust the frequency and amplitude of the output AC signal.
Output Stage
In the output stage, the pulsed current passing through the inverter bridge is further converted into a continuous AC signal. At this point, the AC signal has a specific frequency and amplitude and can be used by devices connected to the inverter's output port. The output stage typically also includes an output filter to remove any residual high-frequency noise and harmonics.
