Direct-current support capacitor capable of effectively absorbing high-frequency harmonic waves

Abstract

The invention relates to a capacitor, and particularly provides a direct-current support capacitor capable of effectively absorbing high-frequency harmonic waves. The direct-current support capacitor structurally comprises a shell, a core group and a composite copper bar are arranged in the shell, the core group is connected with the composite copper bar through a copper hose, two-electrode leading-out ends are welded on the composite copper bar, and potting materials are filled inside the shell and used for fixing the core group and the composite copper bar in the shell. Compared with the prior art, the direct-current support capacitor has the advantages that the design thinking of a traditional branch support thin-film capacitor is changed, the direct-current support capacitor is better in harmonic wave absorbing performance, more convenient to mount, safer and more reliable, and the service life and stability of the direct-current support capacitor can be effectively guaranteed.

Description

technical field [0001] The invention relates to a capacitor, in particular to provide a DC support capacitor capable of effectively absorbing high-frequency harmonics used in large-scale frequency converter / inverter equipment (such as photovoltaic and wind power generation equipment). Background technique [0002] In many power electronic equipment applications, the frequency converter / inverter is a very important part (such as the photovoltaic inverter, the core part of the photovoltaic power generation system). In order to ensure the normal operation of the system, the frequency converter / inverter There is a DC support capacitor for DC support and filtering in front of the converter. The capacitor generally has a large capacity (1000-10000μF), an operating voltage of 400-2000V.DC, and an operating current of 200-1000A. Since the frequency converter / inverter will generate a large number of high-frequency harmonics to feed back to the DC-Link capacitor of the previous stage...

AI Technical Summary

Problems solved by technology

However, this method has a very big defect. Because the length of each core from the lead-out end is different, under the influence of stray inductance, the high-frequency harmonic current generally concentrates on the upper core with a short distance, resulting in uneven heat generation of the capacitor. Some cores tend to exceed the applicable temperature of the capacitor, and eventually the life of the capacitor will decrease or fail; and generally to solve this problem, people will add a set of filter capacitors after the DC support capacitor in circuit design in order to absorb its high frequency Harmonic, the installation volume of such capacitor products is relatively large, and the manufacturing cost is high, which cannot meet the requirements of miniaturization, low cost, and high stability for the development of electronic equipment products.

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