The pros and cons of film capacitor self-healing

With the development of technology, electronic, home appliances, communications and other industries have become shorter and shorter, and film capacitors have become an indispensable electronic component for the upgrading of the above industries due to their good electrical performance and high reliability. . Film capacitors are widely used in electronics, home appliances, telecommunications, electric power, electrified railways, hybrid electric vehicles, wind power generation, solar power generation, etc., except for its non-polarity, high insulation resistance, excellent frequency characteristics, and low dielectric loss. In addition to its characteristics, it also benefits from its self-healing properties. Let's talk about the advantages and disadvantages of film capacitor self-healing.

Film capacitors have self-healing properties, which are characteristic of film capacitors. It is divided into discharge self-healing and electrochemical self-healing. Because of this characteristic, many times the film capacitor is damaged and does not need to be replaced. In many cases, it can self-heal, so it can reduce the cost of replacing the capacitor, reduce the maintenance cost, reduce the troubleshooting, the time of the machine failure, etc. This is Its advantages, but this self-healing feature also has its shortcomings.

The disadvantage of the self-healing property of the film capacitor is that it causes a current pulse when it is self-healing, which brings signal interference to the circuit and reduces the signal-to-noise ratio of the circuit. Therefore, we can see that in some particularly demanding circuits, such as high-fidelity audio circuits, high-precision communication circuits, etc., film capacitors will not be used, and some will also reduce the use and prevent the film capacitors from self-healing during operation. Otherwise it will have an impact on the circuit.

Another disadvantage of the self-healing feature is the gradual reduction in the capacity of the capacitor used. If the capacitance is working, the self-healing times are many, which will result in a significant decrease in the capacity and insulation resistance, a large increase in the loss angle, and rapid failure of the capacitor. Therefore, pay attention to reduce the number of times the capacitor self-healing.