Film capacitors and dielectric features

The performance of film capacitor counts on its dielectric features

How the dielectric impact the performance of film capacitors? The dielectric features of film capacitors shown as followings: 

1. PP film features: non-polar molecule, suitable for various AC/DC occasions; Temperature characteristics are stable from -50~85/125 ℃, and the capacitance basically unchanged); Low dielectric loss, high voltage resistance, good frequency characteristics, easy processing and low cost.

2. PET film features: polar molecules, positive temperature characteristics (Capacitance changes a lot), large dielectric loss; But the dielectric constant is large, good heat resistance, min thickness could be 0.5um, workable for middle-low voltage; Therefore, it's popular used in HEV/48V system.

3. PEN&PPS film features: the characteristics are similar to PET, with better heat resistance, but difficult to process and cost higher.

Based on the above analysis of organic film performance data, considering the cost of material preparation and processing difficulty, polypropylene (PP) is now commonly used as the dielectric for film capacitors, especially in power electronics applications, choose high temperature Polypropylene metallized film capacitors has the following advantages:

1) Stable temperature characteristics, suitable for a wide temperature range (-50~125℃)

2) dielectric loss is small, and stable in a wide temperature range (≤0.0002)

3) Stable frequency characteristics, suitable for a wide frequency range (≤1MHz) 4) high dielectric strength, stable lifespan

5) Non-polar molecules, suitable for AC/DC applications