Film capacitor for DC withstand voltage test

For general electronic components, we generally think that the components used for AC should be AC withstand voltage test, and those used for DC should use DC withstand voltage test. However, the structure of the capacitor itself is quite special. The general electronic components rely on metal-based conductive magnetic conductive materials such as copper and iron.

The insulating material is used as the insulation of the conductor, and in the capacitor, the metal material only serves as an auxiliary function, and the work mainly relies on the insulating material, not only to ensure the insulation of the conductor, but also to store energy as an electric field. It is this characteristic that determines the specificity of a series of capacitor tests. The main purpose of our DC withstand voltage test for film capacitors can be summarized as: whether the quality and performance of the test products are passed, and the development of film capacitors is improved.

Under the trend of miniaturization of electronic components, when the capacity and working voltage are determined, and the volume is small, it is necessary to use a dielectric material with a large dielectric constant and a high working field strength, which is also the key to the development of the capacitor industry. This is the direction we need to work on material applications.

For polypropylene film capacitors with high withstand voltage and low loss, they are mainly partial discharge problems. To reduce the possibility of these problems, capacitors must be manufactured with high quality dielectric materials and strict production processes. For example, the film capacitor core winding workshop should be an ultra-clean air-conditioning environment, and a series of vacuum treatment processes such as vacuum dehydration, exhaust, oil purification and vacuum impregnation should be carried out to eliminate the air and moisture in the medium as much as possible to insulate the medium. Performance achieves results. In addition, the necessary performance tests must be performed before leaving the factory. If the test process is not done properly, it may cause potential damage to the film capacitor or directly damage the film capacitor.