Thin film capacitor for high power three-phase alternating-current filtering occasion

Abstract

The invention relates to the technical field of a power electronic capacitor, in particular to a thin film capacitor for a high power three-phase alternating-current filtering occasion. The thin film capacitor has the advantages that the structure is reasonable, the repeated wiring of multiple capacitors is avoided, the size is small, and the application is safer and more reliable. The thin film capacitor comprises capacitor cores, a connecting copper strip, leading-out terminals, an enclosure, a potting compound and a plastic positioning cover, and is characterized in that the number of the capacitor cores is three, the number of the leading-out terminals is three, the three capacitor cores are connected in pairs to form a triangular connection mode through the connecting copper strip, and the connecting ends of the three capacitor cores are respectively and correspondingly connected with the three leading-out terminals through the connecting copper strip.

Description

technical field [0001] The invention relates to the technical field of power electronic capacitors, in particular to a film capacitor used in high-power three-phase AC filtering applications. Background technique [0002] In the application of power electronic equipment, in order to control harmonics and improve power factor, AC filter capacitors are used on the AC side, especially in some high-power AC / inverter occasions, the operating frequency of the equipment itself is very high , The harmonic current fed back to the power grid is very large. If there is no AC filter capacitor to provide a low impedance channel, it will seriously affect the normal operation of the power grid and related equipment. Because the application occasion is important, and the capacitor passes through a large current when it is working, and the heat is serious, which makes the capacitor easy to generate heat and reduce the service life or even fail, so the requirements for this capacitor are very...

AI Technical Summary

Problems solved by technology

[0002] In the application of power electronic equipment, in order to control harmonics and improve power factor, AC filter capacitors are used on the AC side, especially in some high-power AC / inverter occasions, the operating frequency of the equipment itself is very high , the harmonic current fed back to the power grid is very large. If there is no AC filter capacitor to provide a low impedance channel, it will seriously affect the normal operation of the power grid and related equipment

Because the application occasion is important, and the capacitor passes through a large current when it is working, and the heat is serious, which makes the capacitor easy to heat up and reduce the service life or even fail, so the requirements for this capacitor are very high.

[0003] There are generally two types of capacitors commonly used in this occasion: one is single-phase, and the three-phase line is connected externally by the customer, and multiple capacitors are connected in parallel to increase the heat dissipation surface to solve the problem of excessive current, but such a structure is loose, and the volume occupied by the capacitor Large, high cost; the other is a three-phase one, the internal three capacitors are connected in delta, the oil structure enhances heat dissipation, but the overcurrent capability is low, the maximum can only reach 40~50A, and the anti-harmonic ability is small, often It is not suitable for such high harmonic and high current applications, and there is a risk of oil leakage, which is extremely detrimental to environmental protection, safety and reliability

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