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With the continuous development and progress of society, significant changes have occurred in urban power grid lines, leading to the formation of numerous densely populated electricity load areas. Traditional power supply methods can hardly meet the needs of urban development. Consequently, more advanced and practical electrical equipment—the Ring Main Unit (RMU), also known as an outdoor compact switching station—has emerged. It offers advantages such as small footprint, flexible configuration,

Technical FieldThe utility model relates to the technical field of ring main units, specifically an air-insulated intelligent vacuum ring main unit.Background ArtA ring main unit is an electrical device that integrates high-voltage switchgear into a metal enclosure or assembles it into a interval-type ring main power supply unit. It forms a system by connecting the busbars of various outgoing feeder cabinets, with its core comprising load switches and fuses. It features simple structure, small s

Patent Title: Ring Main Unit Provided with an Air Circulation StructureApplication Publication No.: CN 106099739 AApplication Publication Date: 2016.11.09Application Number: 201610680193.9Application Date: 2016.08.16Patent Agency: Tianjin Sanli Patent & Trademark Agency Ltd. 12107International Patent Classification (Int.Cl.):• H02B 13/00 (2006.01)• H02B 1/56 (2006.01)Abstract:The invention discloses a ring main unit provided with an air circulation structure. The bottom of the ring main unit

0 IntroductionThe application of live bypass cable working technology in distribution networks has significantly reduced power outage times caused by fault repair and planned maintenance. This technology utilizes mobile power equipment such as bypass cables, bypass load switches, and cable joints to form a miniature temporary power supply network, replacing the existing operational line to supply power to customers.Initially, this technology was primarily used for the maintenance of 10kV overhea

With continuous economic development and the increasing impact of electricity on people's lives, particularly in urban areas with high load density, the reliability of power supply is especially crucial. Establishing a distribution network primarily based on a ring main structure can effectively improve power supply reliability, ensure supply continuity, and minimize the impact of distribution equipment failures and maintenance outages. As a key device in the ring main operation mode, the Ring M

1. Type Test System and StandardsType testing verifies the design rationality and safety of eco-friendly insulated ring main units (RMUs), based on IEC 62271-200 and GB/T 3906, and includes: Insulation Performance: For 12kV RMUs, power frequency withstand voltage is 42kV (1 min) for main circuits and 48kV for breakers. Lightning impulse withstand is 75kV (12kV system) or 125kV (24kV system), with 15 standard impulses (1.2/50μs) per polarity. Partial discharge must be ≤10pC at 1.2&a

1. Gas System FaultsThe most critical type of fault in environmentally friendly gas-insulated ring main units is related to the gas system, primarily involving gas leakage and pressure anomalies. Gas leakage in nitrogen-insulated ring main units mainly stems from seal material aging and welding process defects. Statistics indicate that approximately 65% of gas leakage faults are related to O-ring aging, while 30% are caused by inadequate welding. Gas leakage not only affects insulation performan

1 Characteristics of Nitrogen-Insulated Ring Main UnitsThe new generation of nitrogen-insulated ring main units has the following main characteristics: Excellent insulation performance. All live components are sealed inside, with external surfaces made of insulating material, effectively blocking current flow and preventing interference from external charged objects. Strong resistance to external environmental conditions. Both the enclosure and internal insulation materials possess high resilien

1. Air-insulated and SF₆ Gas-insulated Ring Main UnitsAir-insulated ring main units primarily integrate load break switches, disconnectors, or a combination of both with grounding capabilities, operated either manually or electrically. These units may also incorporate fuses to control cable input and output lines. Conversely, SF₆ gas-insulated ring main units, commonly referred to as gas-insulated switchgear, utilize SF₆ gas for insulation and arc quenching due to its high dielectric strength, p

This paper takes the primary isolation break of a certain type of 12kV air-insulated ring main unit (RMU) as the research object, analyzing the electric field distribution and uniformity around it, evaluating the insulation performance at this location, and reducing discharge risk while enhancing insulation performance through structural optimization, thereby providing a reference for the insulation design of similar products.1 Structure of the Air-Insulated Ring Main UnitThe three-dimensional s