Film capacitors are widely used in power electronics applications including but not limited to DC Link, DC output fltering, and as IGBT snubbers.
Film capacitors can be optimized through diferent materials and manufacturing methods. Capacitors are all unique; their fundamentals, the manufacturing processes, advantages and even technology trends are worth highlighting. There are diferent grades and applications critical to considering before choosing the best option.
The film capacitor manufacturing process for three products including plastic box, aluminum can or a customized solution (seen in Figure 2). Within this process, there are key steps to further analyze. Figure 2: Film capacitor manufacturing process. Source: TTI
Types of Film Capacitors “Miler” ( Du-Pont) is famous. 5 Undercoating Resin 6 Outer coating Resin 7 Metallized Film 8 Metallicon (Metal spray) 3-4 Classification by Armoring 4. Characteristics and Performance Typical characteristics are shown below. (Capacitances are 0.1uF) 5. Manufacturing Process 6. Applications and Features
Film capacitors are widely used for DC fltering in power supplies. Their function is to smooth out the DC voltage waveform after rectifcation. As with all switching devices, IGBTs are subjected to voltage transients during turn-of operation. Voltage transients result from energy trapped in the circuit’s stray inductance.
Renewable energy systems such as solar inverters, windmill systems and various energy storage systems (ESSs) will incorporate film capacitors. Industrial uninterruptible power supplies (UPSs), inverters, motor controllers, charging systems and power supplies require many film capacitors.