INDUSTRLAL electronic
Structure of Power Capacitor
2021-08-12 15:09:00
The rated voltage under the rated voltage is called a low-voltage capacitor, and the capacitor above 1kV is called a high-voltage capacitor. They are all three-phase and delta-connected lines. The internal components are connected in parallel, and each parallel component has an independent fuse; high-voltage capacitors are generally single-phase. The internal components are connected in parallel. The shell is welded with a sealing plate, and the core is made of capacitive elements connected in series. The capacitive elements use aluminum foil as electrodes and are insulated with composite films. Underwear insulating oil (mineral oil or dodecylbenzene, etc.) is used as the impregnation medium.
(1) Capacitor element.
The aluminum foil electrode is wound with a solid medium of a certain thickness and number of layers. Several capacitor elements are connected in parallel and in series to form a capacitor core. In high-voltage capacitors with a voltage below 10kV, each capacitor element has a fuse as the internal short-circuit protection of the capacitor. When a component is broken down, other intact components are discharged, causing the fuse to blow quickly within milliseconds, and the faulty component is cut off, allowing the capacitor to continue working normally.
(2) Impregnation agent.
The capacitor core is generally placed in an impregnating agent to improve the dielectric strength of the capacitor element, improve partial discharge characteristics and heat dissipation conditions. The impregnating agent usually includes mineral oil, chlorinated biphenyl and SF6 gas.
(3) Shell and casing.
The shell is generally welded by thin steel plates, the surface is coated with flame-retardant paint, the casing cover is welded with outlet bushings, and the wall of the box is welded with hanging climbers and grounding bolts. The cover of the large-capacity collective capacitor is also equipped with an oil conservator or a metal expander and a pressure release valve. The wall of the box is equipped with a sheet radiator and a pressure-type temperature control device. The terminal is led out by the outlet porcelain sleeve.
The above is the introduction to the structure of power capacitors. weidy, a capacitor manufacturer with 20 years of experience, provides you with services such as film capacitor processing and varistor production. For more information, please contact us.
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