China's first ultra-high-voltage double-break circuit breaker without grading capacitors has been successfully developed.

It has been reported by a Chinese column-type circuit breaker manufacturer that its independently developed LW62-420/T5000-63 column-type circuit breaker has successfully passed the full set of type tests in accordance with IEC standards, marking the birth of China’s first double-break, grading-capacitor-free circuit breaker at Pinggao.

In recent years, the Chinese column-type circuit breaker manufacturer has focused on breaking through key technologies such as high-breaking-capacity, low-operating-energy arc-quenching chambers and enhancing electrical insulation performance, achieving oil-free actuation for ultra-high-voltage (UHV) circuit breakers to support safe and reliable operation of large power grids. Meanwhile, to further promote the “going global” strategy for China’s major power equipment, the company established a dedicated R&D task force. By comparing international IEC standards, national GB standards, and other relevant validation criteria, and aligning with technical tender requirements of different markets, the team finalized the product’s technical specifications and launched the development of the LW62-420/T5000-63 column-type circuit breaker.

Through systematic conceptual design, theoretical calculations, and scientific simulation-based verification, a prototype of the LW62-420/T5000-63 spring-operated column-type circuit breaker was designed and manufactured based on a dual-motion, double-break arc-quenching chamber configuration without grading capacitors. Test results confirmed that the product achieves a rated short-circuit breaking current of 63 kA, a rated short-circuit making current of 171 kA, meets the E2-class electrical life requirement, and has a mechanical life of 10,000 operations—fully satisfying market demands for high-parameter 420 kV column-type circuit breakers overseas and high-parameter 363 kV column-type circuit breakers domestically.

“The technical specifications and performance of this product fully meet the international and domestic requirements for high-parameter, oil-free 363/420 kV circuit breakers,” said a responsible official from the Chinese column-type circuit breaker manufacturer.

The LW62-420/T5000-63 column-type circuit breaker is equipped with a spring operating mechanism and features a dual-motion arc-quenching chamber structure. It operates with low operating energy, achieves oil-free drive, and adopts a “T”-shaped double-break layout, facilitating primary wiring in engineering applications. The design eliminates grading capacitors, reducing maintenance requirements and lowering the risk of pollution-induced flashovers. The product offers advantages including simple structure, high reliability, and easy installation, with overall technical parameters reaching an internationally advanced level.

In recent years, the Chinese column-type circuit breaker manufacturer has adhered to innovation-driven and market-oriented development, continuously tackling critical “bottleneck” technologies, mastering core UHV switchgear technologies, breaking foreign technological monopolies, and realizing localized, independent design and manufacturing of key UHV switchgear equipment. Moving forward, the company will further implement the innovation-driven development strategy, develop more technologically advanced, stable-performing, and high-quality power equipment, and contribute Pinggao’s strength to the construction and reliable operation of power grids.