Why does the electrolytic capacitor explode? How to avoid?

There are electrodes, dielectric materials and electrolytes in the electrolytic capacitor. According to its structure and possible working conditions, the causes of electrolytic capacitor explosion are as follows:

1. The electrolyte will expand when heated, and when it expands to a certain extent, it will leak out of the outer casing of the capacitor. This is commonly known as leakage.

2. When the temperature rises slowly, the electrolyte in the electrolytic capacitor leaks out slowly; but when the temperature rises very fast, the internal expansion speed of the electrolytic capacitor is very fast, and the outer shell of the electrolytic capacitor is opened and even broken. The entire outer casing, this is the explosion.

3. The reason why the temperature of the electrolytic capacitor rises is that the power consumption of the electrolytic capacitor increases abnormally and exceeds the power dissipated by itself. The source of the power consumption increase may be: electrolytic capacitor overvoltage; large ripple current; opposite polarity.

Once an electrolytic capacitor with a relatively large capacity explodes, its power may endanger personal safety. Therefore, the electrolytic capacitor with large capacity is not only designed from the perspective of performance, but also from the safety point of view. There are many electrolytic capacitors that will design explosion-proof slots at the top of the capacitors, and some open explosion-proof holes beside the pins. When it is enlarged, it will open the explosion-proof valve relief pressure to avoid explosion.

In order to avoid an explosion accident of the electrolytic capacitor, the following measures are taken for the most basic cause of the explosion of the electrolytic capacitor.

1. The designed electrolytic capacitor has a high withstand voltage.

2. Select the high-frequency electrolytic capacitor in the case of large ripple. If possible, connect a capacitor with high frequency and high frequency characteristics in parallel with the electrolytic capacitor, such as monolithic capacitor.

3. Strictly avoid the polarity reversal of electrolytic capacitors.