Thin film capacitor applicable to DC-link occasion

Abstract

The invention relates to the technical field of power electronic capacitors, and especially relates to a DC-link capacitor used for alternating current/inversion equipment as direct current link and filtering, in particular to a thin film capacitor applicable to a DC-link occasion. The thin film capacitor has the advantages of large capacity, small size, low cost, reliability, stability, high safety performance and the like. The thin film capacitor can extensively replace electrolytic capacitors in the DC-link occasions of the power electronic field. The thin film capacitor comprises a capacitor core and is characterized in that the capacitor core is formed by winding a metallized polypropylene thin film, wherein the metallized polypropylene thin film comprises a polypropylene thin film medium and a capacitor plate, and the capacitor plate is a metal coating plated on the polypropylene thin film medium in an evaporation manner.

Description

technical field [0001] The invention relates to the technical field of power electronic capacitors, in particular to a DC-link capacitor used for DC support and filtering on AC / inverting equipment, specifically a film capacitor used in DC-link applications. Background technique [0002] DC-link capacitors are widely used. The capacitor is connected in parallel on the DC side of the rectifier bridge to filter and stabilize the voltage. Because the DC-Link capacitor requires a relatively high capacity, people have mostly used electrolytic capacitors for a long time. Because electrolytic capacitors have A single capacitor has the advantages of large capacity and small size, but compared with the advantages of electrolytic capacitors, its disadvantages are also obvious, that is, low withstand voltage, unstable performance and short life. [0003] The dielectric properties of alumina used in electrolytic capacitors and the conductivity of the electrolyte limit its maximum withsta...

AI Technical Summary

Problems solved by technology

[0006] Although the advantages of film capacitors replacing electrolytic capacitors are already obvious, they have not been able to be realized in most of these applications for a long time, because the factors that limit their wide-scale promotion and use are also very realistic, that is, the film capacitors that replace electrolytic capacitors are now a single capacitor Small capacity and large volume, generally about 4 to 10 times larger than electrolytic capacitors of the same capacity. Due to the consideration of cost and ease of use, the application of existing film capacitors to replace electrolytic capacitors cannot be realized for the time being.

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