What are the functions of film capacitors in new energy vehicles

Film capacitors are a type of capacitor that are widely used in electronic products. Film capacitors usually use metal foil as electrodes and are wound with plastic film materials such as polyethylene and polypropylene to form a cylindrical structure.In daily work, film capacitors store electrical energy through electrodes. Compared with ordinary capacitors, they have non-polarity, high impedance, excellent frequency characteristics and less dielectric loss.In analog circuits, it is widely used because it can usually ensure the quality of transmitted signals and reduce distortion.In new fields, film capacitors are widely used in industry, photovoltaic, wind power, and new energy fields due to their good safety and high voltage resistance.

Due to its good high-voltage bearing capacity, film capacitors are expected to benefit greatly from the future 800V automotive platform upgrade process. When the electric car starts the motor and generator, an inverter circuit that converts DC to AC is used. While semiconductor switches such as IGBT and SiC are used, corresponding capacitors are also needed to stabilize the high-voltage line.

Compared with other capacitor products, film capacitors are more suitable for high-voltage platforms. Unlike traditional consumer electronics, automotive electronics are related to vehicle driving safety and may face more harsh environments during use, so the quality requirements are more stringent.For example, the temperature requirements for engine peripheral components are between -40℃ and 160℃, while those for ordinary civilian consumer electronics are usually between 0℃ and 40℃. In addition, the requirements for humidity, mildew, harmful gas erosion, service life, etc. are higher for automotive electronics than for consumer electronics. This has greatly increased the difficulty of manufacturing automotive electronics and also put forward higher requirements for related companies.

Compared with aluminum electrolytic capacitors, film capacitors have higher temperature resistance and can carry higher voltages. Their surge voltage resistance is also about 1.5 times greater than their rated voltage, making them very suitable for new energy vehicles, especially new energy vehicles on high-voltage platforms.

Film capacitors improve the withstand voltage level of electronic control. Since film capacitors are mostly used for DC support, they can absorb high-voltage pulse current from the DC input end to protect other components such as power semiconductors. Usually, each power semiconductor device is equipped with a film capacitor. If multiple motors are used in luxury models, the use of film capacitors will also increase accordingly.