The inverter stage process of power inverter

The inverter stage of the Power Inverter is a key step in converting rectified DC power into AC power. This stage achieves precise control of the output waveform by using high-frequency switching devices and advanced control technology.

Selection of High-Frequency Switching Devices:

Inverters use high-frequency switching devices, such as metal-oxide-semiconductor field-effect transistors (MOSFETs) or transistors (IGBTs), as electronic switches. These devices feature fast switching speeds and high efficiency, making them suitable for high-frequency inverter operation. Selecting the appropriate switching device is critical to the performance of the entire inverter stage.

Inverter Topology:

The topology of the inverter determines the connection method of the switching devices, which directly affects the quality and efficiency of the output waveform. Common inverter topologies include single-phase bridge inverter, three-phase bridge inverter, etc. Different topologies are suitable for different application scenarios. Choose the appropriate topology according to your needs.

Pulse Width Modulation (PWM):

Pulse width modulation is one of the core technologies of inverter control. By adjusting the on-time (pulse width) of the switching device, precise control of the output waveform amplitude can be achieved. PWM technology typically generates an appropriate pulse width modulation signal by comparing a reference signal to a triangular waveform. This technology not only improves the quality of the output waveform, but also helps reduce the harmonics generated by the inverter.

Output Filtering:

The output of the inverter usually also contains some high frequency noise and harmonics. In order to ensure the quality and stability of the output power supply, an output filter circuit is usually used for further processing. This can include components such as inductors, capacitors and filters to remove unnecessary high frequency content.

Current and Voltage Closed-Loop Control:

The control system of an inverter usually includes closed-loop control loops for current and voltage. These loops use sensors to monitor output current and voltage and then adjust the pulse-width modulated signal to maintain the output waveform at a predetermined target value. Closed-loop control helps the inverter adapt to different loads and working conditions and ensures the stability of the output waveform.

Overcurrent and Overvoltage Protection:

Inverters are also typically equipped with overcurrent and overvoltage protection mechanisms to prevent damage to the inverter and connected equipment under abnormal operating conditions. These protection mechanisms ensure the safety and reliability of the system by monitoring current and voltage and cutting off the output in time.