High-voltage integrated static and dynamic self-voltage-sharing vacuum arc-extinguishing chamber

Abstract

A high-voltage integrated static and dynamic self-voltage-sharing vacuum arc-extinguishing chamber comprises an upper side annular ceramic capacitor, a lower side annular ceramic capacitor, an upper end external voltage-sharing shielding case, a lower end external voltage-sharing shielding case, an epoxy solid sealing material, an interface buffering agent (such as silica gel and a coupling agent)and a high-voltage vacuum arc-extinguishing chamber (such as a 40.5 kV vacuum arc-extinguishing chamber or a 72.5 kV vacuum arc-extinguishing chamber). The two annular ceramic capacitors are connected in series, and the middle connection part is connected with a sealing ring in the vacuum arc-extinguishing chamber main shielding case, thereby achieving the voltage sharing of the vacuum arc-extinguishing chamber main shielding case. An upper electrode of the upper side annular ceramic capacitor is connected with the upper end external shielding cover, a lower electrode of the lower side annular ceramic capacitor is connected with the lower end external shielding cover, and the series connection whole serves as a voltage-sharing capacitor to be connected to the two ends of the vacuum arc-extinguishing chamber in parallel, thereby achieving the voltage sharing among all fractures of the multi-fracture vacuum circuit breaker formed through series connection. Charge at the middle ring participates in unbalanced charge compensation after arcing through the annular ceramic capacitors which are connected up and down, so that the dynamic voltage difference is reduced, and dynamic self-voltage-sharing is realized. A gap of 5-10mm is formed between the annular ceramic capacitor and the vacuum arc-extinguishing chamber shell, epoxy solid sealing is convenient to pour, epoxy solid sealingintegration is adopted outside the annular ceramic capacitor, and heat dissipation holes are uniformly distributed in the voltage-sharing shielding cover outside the upper end part and the lower end part, so that the temperature rise requirement of an operation working condition is met. A traditional external parallel voltage-sharing capacitor is replaced, voltage sharing of a main shielding caseof the vacuum arc-extinguishing chamber and static and dynamic self-voltage-sharing of multi-fracture series connection can be achieved, and the multi-fracture vacuum circuit breaker serves as a basicunit of the compact tank-type multi-fracture vacuum circuit breaker.

Description

technical field [0001] The invention belongs to the field of vacuum interrupters, in particular to a high-voltage integrated static and dynamic self-equalizing vacuum interrupter. Background technique [0002] Vacuum circuit breakers are widely used at voltage levels below 35kV, limited by the saturation effect of vacuum gap breakdown voltage. The voltage level of single-break vacuum interrupters is generally lower than 126kV. In order to achieve vacuum circuit breakers in the field of ultra-high voltage (above 330kV) , it is necessary to use multiple single-break vacuum interrupters in series to form a multi-break vacuum circuit breaker. [0003] Due to the influence of stray capacitance, multi-fracture vacuum circuit breakers need to be equipped with equalizing capacitors to achieve the equalizing effect of each fracture. The traditional way is to use external parallel capacitors or resistance-capacitance elements, but the additional equalizing elements have large insulati...

AI Technical Summary

Problems solved by technology

At present, the US patent US7466385 B1 proposes a self-equalizing vacuum interrupter structure using a resistance-capacitance mandrel. The contact structure of the vacuum interrupter adopts a hollow ring-shaped contact structure. It is integrated into a cylindrical insulating operating rod, and the intermediate shield is coaxially arranged between the cylindrical insulating operating rod and the middle of the annular contact to avoid the arc between the annular contacts from sputtering on the outer surface of the cylindrical insulating operating rod, and the cylindrical insulating The operating rod is connected to the moving contact of the vacuum interrupter, so that the vacuum interrupter can be driven to close and open. At the same time, the internal resistance-capacitance mandrel can realize the pressure equalization between the fractures. The advantage of this structure is that it does not need an external synchronous operating rod to drive , the disadvantage is that the structure of the vacuum interrupter is complex and the diameter is large

Chinese patent CN108878212A proposes a vacuum interrupter for a self-equalizing multi-fracture vacuum circuit breaker, which adopts a scheme based on the integration of the BST ceramic shell and the interrupter shell, but the mechanical strength and capacitance of the ceramic capacitor limit its length. At the same time, the influence of the sealing ring in the main shielding cover of the vacuum interrupter of 40.5kV and above is not considered. The derived main shielding cover voltage equalization and dynamic charge compensation realize dynamic self-balancing control

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