Content: The inverter drive board is a signal amplifier board that mainly integrates the drive IGBT circuit. The function of the drive circuit is to control the IGBT module to complete the inverter function after the six PWM signals of the CPU mainboard are isolated and amplified by the optocoupler. It contains isolation circuits, amplifier circuits, and power supply circuits for driving. And the drive of the upper three bridges is an independent power supply, and the drive of the lower three bridges is a common power supply. The driving circuit has problems. Generally, the conduction performance of a certain path is deteriorated, or the optocoupler is burned, resistance and capacitance, etc. The device or the driving power supply voltage is abnormal, which will cause problems with the IGBT on and off, resulting in unbalanced three-phase voltage output, as long as the IGBT module is blown, or the three-phase unbalanced, or overcurrent and other problems, Always check and repair the driver board.
The most common characteristics of the drive circuit are three-phase voltage and current imbalance and output phase loss. If the fast melting of an inverter is burned out or the IGBT is broken, do not directly install new accessories. At this time, you need to check the drive circuit to see Is there any appearance of fire or discoloration? As long as the WVW three-phase output is unbalanced, or there is jitter at low frequencies, startup, and overcurrent and overload alarms, you must carefully check the driver board. When it is determined that the driver board is normal and the IGBT module is needed, the P pin needs to be disconnected from the bus bar, and several large light bulbs are connected in series in the middle for current limiting resistance energization protection.