With the surging wave of global environmental protection upgrades and energytransitions, the process of green transformation of power equipment is constantly accelerating. Under thejoint efforts of grid users and manufacturers, the environmental protection solution for the circuit - breakerfunctional units of ring - main units (RMUs) has been widely applied in power grids. However, as theswitchgear at the end of the distribution network, a single circuit - breaker solution for RMUs is difficult tomeet the diverse needs of various users in diferent scenarios and also increases customers investmentexpenditures. Against this backdrop, improving various application functional units of RMUs has becomethe key to promoting environmentally friendly RMUs. Recently, ABB has innovatively launched acompressed - air - type environmentally friendly gas load - break switch ring- main unit, injecting newimpetus into the green transformation of power equipment.

For a long time, SF6 (sulfur hexafluoride) gas has dominated the field of power equipment due to itsexcellent insulation and arc - quenching performance. However, its global warming potential is as high as24,300 times that of carbon dioxide, posing a significant obstacle to the global carbon - reduction process.The load - break switch solution is widely used in RMUs. Although mature SF6 - interrupting load - breakswitches are technologically mature and cost - effective, the industry is facing the dilemma of being unableto balance "environmental friendliness, economy, and high performance.

The 12kv Safe Air compressed - air - type environmentally friendly gas load - break switch ring - main unitlaunched by ABB this time has successfully filled the gap of economical and environmentally friendlysolutions in the field of medium - voltage ring - main equipment, providing an innovative path with bothtechnical feasibility and economy for the green upgrade of power grids.

This product adopts an innovative compressed - air arc - quenching structure and continues to use thespring - operated mechanism that has been verified in the market for more than two decades, ensuring thestability and reliability of the equipment, The strength of the drive chain meets the new standard GB19852023, and a highly reliable electric field design is adopted to guarantee the mechanical and electricalperformance. The product can be flexibly combined with circuit - breaker cabinets that meet the standardspecifications of the State Grid, supports flexible common - box solutions, and meets various applicationscenarios and usage standards. In addition, the equipment has flexible expansion methods, allowing fortop or side expansion. lt is compatible with ABB's Safe Digital digital solution for RMUs, further enhancingthe level of intelligence.

ABB's compressed - air - type environmentally friendly gas load - break switch has achieved three majorcore technological breakthroughs. In terms of compressed - air arc- quenching technology, its arc -quenching device consists of moving and stationary main contacts, arcing contacts, and a piston. lt usesthe overpressure generated by the piston compressing the gas to "blow out" the arc and interrupt the loadcurrent. During the closing and opening processes, the arc action is concentrated on the arcing contactsreducing the wear of the main contacts, extending the maintenance cycle, improving the service life andstability of the equipment, and having a simpler, more stable, and reliable contact structure. Thecompressed - air technology has been widely used in high - voltage circuit breakers. ABB has innovativelyapplied it to 12kV load - break switch units, overcoming the performance bottleneck ofdry - air medium.

The "stagnation point" design of the compressed - air switch is the "precise braking point" for safe poweroff. lt achieves efficient arc - quenching through the precise control of the synergistic effect of airflow andmechanical action, utilizing gas - dynamic characteristics to form a local high - pressure area. When theswitch opens, the moving contact drives the piston to compress the insulating gas, generating a high -speed airflow that blows toward the arc. During the contact - separation process, a "stagnation point" withzero gas flow velocity is formed, creating a local high pressure. This local high pressure compresses the arcdiameter through the "thermal contraction effect," increases the arc resistance, enhances the dielectricinsulation strength, effectively suppresses arc reignition, ensures arc extinction, and improves the switch'sbreaking capacity.

In terms of environmental protection and economy, this product uses dry air instead of SF6, with anextremely low leakage rate (<0.01%). it uses dry air (composed of 19.5 -23.5% oxygen and the remainingnitrogen) as the insulating medium, ensuring that the product does not cause harm to the environmentthroughout its entire life cycle. At the same time, it adopts a simpler, more efficient structure and design.offering higher cost - effectiveness.

Under the major trend of accelerating global green transformation, ABB has stated that it will continue toinnovate in environmentally friendly power technologies, launch environmentally friendly productssuitable for various scenarios such as new - energy power plants, smart grids, and industrial parks, providemore efficient and green solutions, assist in the sustainable development of the power industry, promotethe clean transformation of the global energy structure with innovative technologies, and contribute tobuilding a green future.