A dry-type metallized film capacitor gas-sensing protection device and method

Abstract

The invention discloses a protection device and method for a metallized film capacitor. The inside of the dry metallized film capacitor is not potted or has a dry structure with potting, and there is a gap of a certain height at the top of the capacitor. The gas sensitive protective device composed of heat conduction type hydrogen sensor and its detection circuit is installed on the top of the capacitor. When breakdown occurs in the internal components of the capacitor, a large amount of gas is generated inside the component and escapes, and the gas will eventually collect in the gap at the top of the capacitor. In the component gas production, the detected hydrogen volume accounts for about 85%. Therefore, the gas production will lead to the change of the hydrogen concentration in the space on the top of the capacitor, which will lead to the change of the output signal of the detection circuit, and realize the detection of the internal fault of the metallized film capacitor. After the fault signal is detected, the power supply of the capacitor can be cut off from the outside, so as to prevent accidents such as capacitor burst caused by the further development of the capacitor fault, and realize the fault detection and protection of the capacitor.

Description

technical field [0001] The invention belongs to the technical field of electrical equipment, and more particularly relates to a gas-sensitive protective device and method for a dry-type metallized film capacitor. Background technique [0002] The metallized film capacitor is composed of a metallized film. Because the thickness of the metal electrode is very thin, only at the nm level, it has self-healing characteristics. The energy storage density of the dielectric film is improved, and the volume of the energy storage element is reduced. At present, metallized film capacitors are often used as energy storage devices for pulse power supplies, or for AC and DC filtering and reactive power compensation in power systems. [0003] When the internal medium of the metallized film capacitor is obviously aged, operated in a high temperature environment, the withstand voltage is too high, or the above factors act at the same time, the metallized film capacitor will have a breakdown ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the above defects or improvement needs of the prior art, the present invention provides a dry-type metallized film capacitor gas-sensing protection device and method. Detect the internal fault of the capacitor and give a signal to cut off the power supply of the dry metallized film capacitor, thereby overcoming the technical problem of poor reliability in the existing method

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