Wadannan abubuwa wata duka cikin kammalawa na ƙananan karamin shiga gida na birnin?

A cikin farkon da dama na gaggawar jamiyar sanyi na tarihi mai tsawo, ina da shawarwari ga tattalin zamani da kuma amfani da takardun abubuwan sanyi na kasa. A matsayin babban wurin elektriko a matsayin da na biyu na jamiyar sanyi, tattalin da kuma ingancin wannan wurin yana haɗa da hankali da zama da yanayin rayukansu a kan al'adun kofin sanyi. Wannan ita ce tushen bayanin masu ma'adanci na tattalin abubuwan sanyi na kasa, ta hanyar tattalin da kuma amfani da su.

1. Tattalin Daidaito na Kiyaye da Kudin Kirkiro

Tattalin wurin sanyi na kasa yana bukatar da ci gaba da muhimmancin tattalin da kuma kungiyoyin kasuwanci. Yana bukatar da ka duba masana, muhimman abubuwa, da kuma nasarorin wurare da ke faruwa. Masu kafin da suka fi sani sun hada da circuit breakers da kuma load switches, kuma wasu sun amfani da combined electrical appliances. A cikin tattalin, an yi tasiri a matsayin “load switch + fuse”—wannan irin tashin yana da kiyaye mai yawa da za a iya amfani da shi wajen kula da kudin kirkiro, layout, da kuma tsari na wannan wurin. Abubuwan sanyi masu kafin da suke amfani da load switches kawai suna bukata da ya gane da tattalin da ke faruwa don in ba da standardization da kuma universality.

Daga baya, an samu sabbin irin kirkiro: load switch cabinets, combined electrical appliance cabinets, circuit breaker cabinets, multi-circuit cabinets, da sauransu. Tattalin tashin kafin da suka fi sani yana bukatar da ci gaba da uku abubuwa mafi muhimmanci: current-carrying capacity, electric force withstand capability, da kuma heat dissipation efficiency:

• Abubuwan Sanyi: Amfani da karfi na closing electric force don in tabbatar da adana soƙe masu kafin da suka fi sani a cikin testai na dynamic and thermal stability, ta hanyar in tabbatar da mechanical and electrical performance.

• Zabbar Busbars: Zabi busbars na circular ko flat ta hanyar current-carrying capacity, kula da current density, da kuma balanci bayan current-carrying da heat dissipation.

• Tushen Electrical Connection: Dynamic and static contacts, sliding/fixed connections yana bukatar da low contact resistance. Idan an yi amfani da metal conductors daban-daban, an amfani da processes such as tinning and silver plating don in kula da electrochemical corrosion da kuma in kammala contact failure.

Tattalin compartments yana bukatar da ci gaba da “safety first, process adaptation, and convenient operation and maintenance”: protection level ba yanzu ba yake kadan IP3X, zabe material (metal/non-metal) ta hanyar buƙatun, da kuma configure pressure relief devices and fault arc limiting measures—don in kula da gas na high-pressure a cikin channel na relief idan an samu internal arc faults, don in tabbatar da dalilin wurin da kuma mutanen.

2. Tushen Insulation Structure Design Daga Farkon Tsari

Switchgear yana bukatar da ci gaba da maximum operating voltage da short-term overvoltage (atmospheric and internal overvoltage) zuwa lokacin. Tattalin insulation yana bukatar da ci gaba da environmental adaptability, material selection, structure optimization, da kuma process control:

(1) Electric Field Optimization and Insulation Coordination

Tsarin conductors yana haɗa da distribution na electric field a cikin cabinet. A cikin tattalin, amfani da rounded copper bars, round bar busbars, da kuma optimize shapes of dynamic and static contact seats, internal conductors, and support electrodes don in kammala sharp points and edges, ta hanyar in tabbatar da electric field to be more uniform. Ta hanyar software na finite element analysis (such as ANSYS Maxwell), za a iya locate weak insulation links. Through layout adjustment and structure optimization (such as the application of shielding technology), za a iya uniformize electric field and reduce the maximum field strength, improving insulation reliability.

(2) Application Logic of Multiple Insulation Media

• Air Insulation: For composite insulation with air as the main body, the electrical clearance and creepage distance specified by the standards must be strictly followed in the design to balance insulation performance and equipment compactness.

• Gas Insulation: Gas-insulated cabinets mostly use SF₆, N₂, dry compressed air, or mixed gases as insulation media (in the low-pressure range). Although the gas pressure is not high, the sealing design is crucial—attention must be paid to the component changes of the gas due to permeation during long-term operation (such as air infiltration and insulation gas exudation). For gas-filled compartments without arc decomposition products, the moisture content must be precisely controlled: when the rated pressure ≤ 0.05MPa, it should be ≤ 2000μL/L; when > 0.05MPa, the allowable value of moisture content is calculated according to the saturated water vapor pressure at -10°C.

• Interface and Solid Insulation: When solid insulation parts are butted, elastic materials such as silicone rubber are used to eliminate air gaps and improve the interface insulation level (related to surface pressure, finish, and contact length). Using materials such as epoxy resin and silicone rubber to cast and vulcanize and package high-voltage components, and covering them with a grounding/semiconductive layer, can significantly improve the safety level, reduce the equipment volume, and simplify the layout.

3. Precise Design of Mechanical Transmission and Interlocking System

Mechanical transmission covers links such as circuit breaker operating mechanisms, disconnectors, earthing switches, and door interlocks. The design needs to be optimized from dimensions such as principle, layout, force mode (pressure/tension), span, transmission ratio, stroke angle, and mechanical efficiency: simplify the structure, reduce the number of parts, and lower the operating force, achieving “reasonable force bearing, reliable transmission, stable operation, and convenient operation and maintenance”.

The “five-prevention” interlocking is the core of ensuring operation safety—mechanical interlocking is preferred (composed of levers, connecting rods, baffles, etc. to form a lock, with clear procedures, intuitive and reliable); if the components are far apart or mechanical interlocking is difficult to implement, electrical interlocking is supplemented; intelligent cabinets can be superimposed with microcomputer software programming interlocking (used in conjunction with mechanical interlocking) to build a multi-level safety protection system.

4. Construction of a Reliable Earthing System

The earthing design needs to cover the dual requirements of “operation safety” and “fault withstand”:

• During maintenance, the earthing switch can reliably earth the main circuit according to regulations.

• The bottom frame of the shell is equipped with earthing conductors and terminals suitable for fault conditions, and the cabinets are interconnected by conductors, with a dedicated circuit between the earthing switch and the earthing conductor.

• The earthing conductors, connection circuits, and connections between cabinets must withstand the rated short-time/peak withstand current.

• The frame, cover plate, door, partition, and other components are electrically continuous to ensure the earthing connection of functional units.

• The DC voltage drop from any point of the shell metal parts to the earthing conductor through 30A is ≤ 3V, ensuring the effectiveness of earthing.

5. Technological Evolution and Development Direction

With the process of power grid transformation and cable undergrounding, multi-circuit distribution units are rapidly iterating towards “miniaturization, modularization, and automation”, which drives the innovative development of SF₆ and composite insulation technologies and high-performance components. In the future, it is necessary to focus on manufacturing process upgrades (such as precision processing and integrated packaging), optimization of cable connectors, iteration of current-limiting fuses, research and development of small operating mechanisms, and innovation of auxiliary components, so as to improve the design and manufacturing level of domestic ring main distribution equipment. Developing a new generation of ring main cabinets with “full working condition adaptation, maintenance-free, high reliability, and miniaturization” to enable distribution automation will become a key direction for industry breakthroughs.