The working principle of an inverter is to high-frequency switch DC power through electronic switching devices, forming a pulse width modulation (PWM) signal, and then convert the pulse signal into AC power through a filter. The basic structure of an inverter includes DC power supply, switching devices, control circuit, and output filter.
- DC power supply: The input power supply of the inverter can be batteries, solar panels, wind turbines, etc.
- Switching device: The core component of an inverter, used to achieve high-frequency switching of DC power. Common switching devices include transistors, IGBTs, MOSFETs, etc.
- Control circuit: used to control the switching state of switching devices and generate PWM signals. The control circuit includes microcontrollers, drive circuits, protection circuits, etc.
- Output filter: used to filter out high-frequency components in PWM signals and obtain the required AC power. Common filters include LC filters, π – type filters, etc.
2、 Factors affecting the output frequency of inverters
The output frequency of an inverter is influenced by various factors, including input power supply, switching devices, control strategies, etc. - Input power supply: The voltage and current characteristics of the input power supply will affect the output frequency of the inverter. For example, the output voltage of a solar panel varies with the intensity of light, which may cause fluctuations in output frequency.
- Switching devices: The switching speed, on resistance, and other parameters of the switching devices can affect the output frequency of the inverter. The faster the switching speed, the higher the output frequency; The smaller the on resistance, the higher the output frequency.
Control strategy: The control strategy of the inverter has a significant impact on the stability and accuracy of the output frequency. Common control strategies include voltage type control, current type control, hybrid control, etc.