Insulation resistance of film capacitor

The application range of film capacitors has become wider and wider, which is due to its non-polarity, high insulation resistance, excellent frequency characteristics (wide frequency range), low dielectric loss, etc. Insulation resistance is also a film capacitor. What kind of characteristics, then what is the insulation resistance of the film capacitor? Today I will tell you about the insulation resistance of the film capacitor.

The insulation resistance of a film capacitor refers to the ratio of the voltage applied across the capacitor to the leakage current, that is, R=U/IL. R is the insulation resistance, U is the voltage, and IL is the leakage current of the film capacitor. There may be many people who don't know what is the leakage current of the film capacitor. When the leakage current of the film capacitor applies the rated DC working voltage to both ends of the film capacitor, we will see that the change of the charging current for charging the capacitor starts to be very large, and the current will follow. Decline with time, reach a relatively stable state when it reaches a certain value, and the magnitude of this current is called leakage current.

Therefore, the capacitance of the film capacitor is C=Q/U, Q is the charge amount, and U is the voltage applied across the capacitor. Combined with the above formula, R = Q / (C * IL) can be obtained, so we can know that the larger the capacitance of the film capacitor, the smaller the insulation resistance, the smaller the capacitance of the film capacitor, and the greater the insulation resistance.