Rockwill Dead Tank Circuit Breakers Empower Intelligent Retrofit of 72.5kV Substations in Extremely Cold Regions

High‑voltage circuit breakers are vital cornerstones for stable power supply in frigid alpine regions.Extremely low temperatures easily trigger SF₆ liquefaction and mechanism failure for conventional substation equipment.

Project Overview

In the intelligent transformation project of a 72.5kV substation in the alpine region of Hulunbuir, Inner Mongolia, our company’s RMR-72.5/126 SF₆ circuit breaker was successfully commissioned. Facing extreme winter temperatures of -40°C, the product utilizes a "two-primary, two-backup" intelligent heat tracing system and a three-phase common enclosure integrated design.

This completely resolves traditional equipment pain points such as low-temperature liquefaction and operation failure, achieving year-round fault-free stability. It provides core security for the border power grid and demonstrates the engineering prowess of domestic medium-voltage equipment in extreme environments.

Exceptional Design · Arctic Resilience

The RHD-72.5/126 circuit breaker features a three-phase common enclosure structure, offering superior gas tightness and a compact footprint. Three-phase mechanical linkage ensures precise synchronization with a mechanical life of 10,000 operations. It is innovatively equipped with a dual-mode intelligent heat tracing system (Conventional / Two-primary, Two-backup), extending the minimum operating temperature to -45°C. The system features real-time monitoring and automatic redundant switching to eliminate risks of SF₆ liquefaction or mechanism jamming.

Built-in high-precision electromagnetic current transformers (iron core winding design) support 50/60Hz dual-frequency adaptation, ensuring stable secondary current output for global metering and protection standards. The entire series has passed rigorous alpine validation, significantly reducing O&M frequency and life-cycle costs through its three core advantages: compact structure, intelligent cold resistance, and international compatibility.

Empowering Infrastructure Development

As a benchmark for environmental adaptability upgrades in domestic medium-voltage circuit breakers, the RMR-72.5/126 has been deployed at scale across grids in Inner Mongolia, Heilongjiang, and Xinjiang. Leveraging its dual-frequency design and international standard compatibility, it provides customized Chinese solutions for power projects in cold-climate countries along the "Belt and Road." Our company adheres to "scenario-driven innovation,"

continuously iterating technologies such as intelligent heat tracing and state perception. Through highly reliable and adaptive products, we help global power grids tackle extreme climate challenges, fulfilling our mission to "ensure every kilowatt-hour of electricity arrives safely."