Rectifier Circuit


The rectifier circuit is the part that converts the input alternating current (AC) into direct current (DC). It is usually composed of diodes or thyristors (SCR). The rectified DC power is used to provide the required power for the inverter.


This part is the first stage of the inverter and determines the conversion efficiency of the power supply.


DC Bus


The DC bus is the circuit part between the rectifier circuit and the inverter. It usually contains electrolytic capacitors to smooth the DC voltage, eliminate high-frequency noise, and ensure a stable DC power supply.


The DC bus stores the DC power of the inverter and is the intermediary part of power storage and conversion.


Inverter Circuit


The inverter is the circuit part that converts direct current (DC) into alternating current (AC) with adjustable frequency. It is usually composed of power semiconductor devices such as IGBT (insulated gate bipolar transistor).


The inverter circuit is the core of the inverter to control the motor speed. It controls the speed and torque of the motor by changing the output voltage frequency.


Control Circuit


The control circuit is the "brain" of the entire inverter, responsible for receiving external control signals (such as instructions from the operation panel, sensor feedback, etc.) and adjusting the working state of the inverter circuit according to these signals.


The control circuit usually includes a microprocessor (MCU) and some auxiliary circuits (such as protection circuits, adjustment circuits, etc.) to realize the inverter's adjustment, protection, fault diagnosis and other functions.


Understanding the basic functions of these four circuits can help you locate problems and make effective repairs when repairing the inverter.