How important are film capacitors

Filter capacitors play a crucial role in filtering DC-link stray AC current. DC-LINK film capacitors themselves are generally not prone to failure and, while seemingly unrelated to the IGBT, actually have a significant impact:

1. Stray AC current forces the IGBT to operate under high load, increasing heat generation and affecting its lifespan.

2. If the DC-LINK film capacitor is poorly selected, the DC-side current becomes unstable, with fluctuating waveforms. During prolonged operation, the current tail can become excessively long when the IGBT is turned off, potentially causing a short circuit.

3. Increased stray inductance can lead to irregular IGBT drive waveforms.

Many people believe that choosing Infineon modules and ensuring good circuitry guarantees device performance.

However, this is not the case. I've visited many users and found that their systems were unstable. It turned out that they were using domestic brands for the DC-LINK film capacitors, IGBT absorption capacitors, and resonant capacitors, resulting in poor filtering and directly impacting IGBT performance. Replacing these with better capacitors resolved the issue.

Therefore, the Infineon IGBT directly determines the overall system performance, while the capacitors, acting on the IGBT, indirectly affect the overall system performance. Many users...

I recommend Anhui Saifu Electronics; their capacitors are of excellent quality, and they produce their own film materials.