The working process of the power module is very special, and the working sequence and voltage increase are divided into three stages. Stage 1 is the rectification of 380V AC power to 400VDC, Stage 2 is the detection of 400VDC, and continues to charge the DC LINK capacitor to 570VDC. Stage 3 is waiting for a pulse enable signal to appear, increasing the DC LINK voltage to 600VDC. Due to the simultaneous provision of start, drive enable, and pulse enable signals, the above three step interval time is extremely short. The IGBT rectifier bridge starts working as soon as the enabling conditions are met. When the IGBT rectifier bridge and pulse distribution circuit experience high current breakdown or pulse order disorder due to voltage instability, humidity, dust accumulation, and other reasons, the surge current impacts the IGBT DC side of the coordinate axis power module through the DC bus, This is the fundamental reason for the short circuit and burning of the power module. When the IGBT rectifier bridge is short circuited, the incoming reactor should play a certain protective role in preventing the current from rising too fast. The decrease in insulation capacity leads to a sharp decrease in inductance, which cannot effectively protect the power module. This is also the secondary reason for the burnout of the power module.
The normal supply range of voltage in China is 380 (1-15%) V-380 (1+10%) V AC. The voltage requirement of the Siemens power module is 380 ± 5 V AC. When the power supply exceeds the voltage required by Siemens, the self-protection function (fuse) of the power module will be lost, and the fuse and three associated electrical components will be broken, resulting in the power module being burned out.
A power module is a power supply that can be directly mounted on a printed circuit board. Its characteristic is that it can provide power for specialized integrated circuits (ASICs), digital signal processors (DSPs), microprocessors, memory, field programmable gate arrays (FPGAs), and other digital or analog loads. Generally speaking, this type of module is called a Point of Load (POL) power supply system or a Point of Use Power Supply System (PUPS). Due to the many advantages of modular structure, modular power supplies are widely used in communication fields such as switching devices, access devices, mobile communication, microwave communication, optical transmission, routers, and automotive electronics, aerospace, etc.