Low-inductance power capacitor

Abstract

The invention relates to a low-inductance power capacitor which comprises a cover plate assembly, a shell and a capacitor core set fixed into the shell. The capacitor core set is formed by overlapping a plurality of capacitance cores in a layering mode. A positive electrode leading copper strip and a negative electrode leading copper strip are mutually overlapped and arranged on the two sides of the non-metal-spraying face of the capacitor core set. Insulating layers are arranged between overlapped parts of the connecting parts of the positive electrode leading copper strip and the negative electrode leading copper strip and a terminal. The metal spraying faces of the two ends of each capacitor core are electrically connected to auxiliary leading copper strips respectively in a welding mode, wherein the auxiliary leading copper strips are transversely arranged. The two ends of each auxiliary leading copper strip of each end of the capacitor core set are fixed to the positive electrode or negative electrode leading copper strip through welding. The double leading copper strips are arranged on the two sides of the capacitor core set, the path for leading currents to the copper strips is the shortest, the current density is reduced, the self-inductance of the capacitor can be reduced obviously, and the safety performance of equipment like a current transformer can be improved.

Description

technical field [0001] The invention relates to a power capacitor, in particular to a low inductance power capacitor. Background technique [0002] At present, the market demand for high-power converters is increasing, and the IGBT power unit responsible for the current conversion task requires higher output current, greater output power, and greater power density. In order to meet these performances of the high-power converter, the self-inductance of the DC support capacitor in the inverter is required to be as small as possible. The higher the switching frequency of the converter, the greater the output current and the greater the rate of change of the current; then the greater the voltage induced on the DC bus. According to the formula: U=L*di / dt, it can be seen that improving the inductance value of the capacitor itself will greatly reduce the induced voltage of the converter under the condition of large output current and high switching frequency. [0003] The high-po...

AI Technical Summary

Problems solved by technology

However, during the long-term operation of the equipment, the absorption capacitor will be damaged, which will inevitably affect the normal operation of the equipment.

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