Reasons for adding CBB capacitor after rectification

Film capacitors are mainly used in electronics, home appliances, telecommunications, electric power, electrified railways, hybrid vehicles, wind power, solar power and many other industries. So why do you need to add a CBB capacitor after the traditional bridge PFC rectification?

If CBB capacitor is not added, only the junction capacitance of the rectifier tube is very small. Once the loop has stray inductance, its resonant frequency is very high and the amplitude is very large. First, it is easy to break through the rectifier tube, and second, EMI is deteriorated. The reason for choosing the CBB capacitor is the price advantage, and the voltage resistance is the second. Second, because the capacitor needs to withstand a high enough surge current, the CBB capacitor with "self-treatment" is selected. PS: "self-healing" effect: surge charging current will cause the capacitance capacity to become smaller, but the CBB capacitor can withstand, the capacity loss is relatively small!

The self-healing principle of CBB capacitor is: when there is a problem or click on the medium of CBB capacitor, the metallized coating at the breakdown point or the problematic position will be volatilized under the action of arc under the action of the arc, so that the capacitor The two poles again form a short circuit and resume normal operation.

Regarding whether or not the capacitor is added, we must understand clearly and use the function of the capacitor! If you have technical questions, please contact us and try to solve it for you.