In the rail transit sector, the DC power supply system is the "energy hub" ensuring stable train operation. Whether it's a subway, light rail, or urban express rail, key components such as traction power supply, DC traction network, and regenerative braking circuit all rely on the reliable operation of the DC system. However, DC systems are susceptible to various overvoltage threats in actual operation, such as switching operation overvoltage, regenerative braking overvoltage, and lightning strike overvoltage. If these overvoltages are not suppressed in time, they can lead to equipment damage or, in severe cases, power outages and train stoppages. As a targeted overvoltage protection device, the DC surge arrester for rail transit, with its precise voltage limiting capability and rapid response characteristics, has become a core barrier protecting the safety of the DC system. Reasons for using DC power supply in rail transit Urban rail transit (metro, light rail, etc.) generally uses DC 750V or 1500V power supply, which is related to its short station spacing, frequent starts and stops, and limited line length. DC traction systems have advantages such as good speed regulation performance, large starting torque, and relatively simple control. At the same time, because of its relatively low power supply voltage and the inductive and loss-free transmission of DC power, it has high efficiency in short-distance transmission. In addition, its mature technology and low overall construction cost make it the mainstream choice for urban rail transit Installation location and reasons for DC surge arresters in subways The 1500V DC system for subways is not a single device, but a closed-loop system composed of four major components: high-voltage AC input, rectification and conversion, DC power distribution, and train current collection. In the subway system, the 1500V DC surge arrester is a key device for overvoltage protection. It is mainly installed inside the DC traction substation and at key nodes of the contact network (or contact rail) along the line, such as the end of the power supply section, the contact network entry point in the station yard, and the ground and elevated sections, to protect the rectifier units, DC switchgear, control and measurement devices, and the contact network itself.   Although some sections of the subway are underground, the overhead contact lines in both the ground and elevated sections, being unshielded outdoor installations, are still vulnerable to lightning overvoltage threats: 1. Outdoor contact lines are susceptible to direct lightning strikes due to their exposed location, potentially injecting extremely large lightning currents; 2. Proximity lightning strikes can also induce high-amplitude pulse overvoltages in the contact lines; 3. Operational overvoltages generated within the system due to frequent train starts and stops, circuit breaker operations, and regenerative braking are also significant. DC surge a...

Gathering Momentum for a New Future in Rail Transit! The 22nd Annual Summit of the World Rail Transit Industry From 30th to 31st in Oct., 2025, the 22nd Anniversary Summit of the World Rail Transitwas held in Beijing. This grand event, bringing together industry authorities, cutting-edge technologies, and strategic wisdom, focused on the core theme of "Strategic Transformation to Promote the Sustainable Development of China's Rail Transit," drawing a new blueprint for the development of the global rail transit industry. Authorities gathered to discuss a new chapter in development. Guo Lin, former Vice Minister of Railways and President of the World Association for the Development of Rail Transit, attended the event and opened the summit with a professional introduction. Guests from supporting organizations such as the Institute of Comprehensive Transportation of the National Development and Reform Commission and the China Urban Rail Transit Association, as well as special co-organizers such as Beijing Subway Operation Co., Ltd. and Beijing Port Subway Co., Ltd., gathered together. Industry leaders such as Alstom China and CASCO Signal also participated deeply, building a multi-dimensional exchange platform linking government, industry, academia, research, and application. Driven by both technological innovation and strategic transformation At the summit, the release of the new book "Research on Railway Power Supply Operation Safety and Technology (2025 Edition)" was a major highlight. This book focuses on safety and technological breakthroughs in the field of railway power supply, providing authoritative technical guidance for industry operation and maintenance. Meanwhile, the unveiling of the book "Digitalization of Railway Power Supply" closely aligns with the background of the construction of "six modern railway systems," proposing a new development pattern of "digital empowerment and intelligent operation and maintenance," and outlining a transformation path for the digitalization, intelligentization, and modernization of railway power supply through a "1-1-5-1-1" action plan. During the keynote speech session, industry experts conducted in-depth analyses on "Strategic Transformation Driving the Sustainable Development of China's Rail Transit." From technological innovation in railway power supply to the digital transformation of the entire industry; from operational optimization of a single rail network to the collaborative development of global rail transit, the guests' sharing combined macro-strategic vision with micro-technical practical application, injecting new momentum into the industry's development. Anchoring the future of sustainable development in the industry Currently, the rail transit industry is at a critical juncture of strategic transformation. This summit serves not only as a review and summary of the 22-year history of global rail transit development, but also as a forward-looking plan for future development...

On October 25, 2025, the Annual Meeting of the Hunan Provincial Architectural Electrical Society was held in Changsha. The meeting brought together council members, key electrical design personnel from major design institutes in the province, member representatives, and representatives from electrical equipment manufacturing enterprises nationwide. Industry elites gathered to explore development trends, technological innovations, and future paths in the architectural electrical industry. The atmosphere was highly academic, and the exchanges yielded fruitful results. Anhui Jinli showcased its intelligent lightning protection system, miniaturized surge protection devices, and smart terminals at the 2025 Annual Meeting of the Hunan Provincial Building Electrical Society, becoming one of the highlights that attracted industry attention. As a supporting unit of this annual meeting, Anhui Jinli Electric, with "Safeguarding Electrical Safety and Driving Technological Innovation" as its core mission, explored cutting-edge trends and practical paths in the field of building electrical engineering with industry colleagues. With two decades of experience inlightning protection system, Anhui Jinli Electric is a leading domestic technology service company specializing in the R&D, manufacturing, and sales of surge protection devices (SPDs) and providing comprehensive lightning protection solutions. Anhui Jinli's key laboratory for surge protection devices possesses all the testing capabilities required by national and international standards such as GB/T18802.11/21/31, IEC61643-11/21/31, and UL1449. It is also the only domestic laboratory to have obtained both UL and TUV witnessed laboratory certifications.Jinli’s technical strength and product reliability have deeply served the electrical safety needs of various scenarios, including railways, new energy, petrochemicals, and industry. From technical demonstrations at the product booth to the exchange of ideas at the conference, Anhui Jinli put its philosophy of "professional empowerment of the industry" into practice. Looking ahead, Jinli will continue to focus on technological innovation, working hand-in-hand with partners in the building electrical field to jointly build a safer and more efficient electrical ecosystem, injecting new momentum into the industry's high-quality development. This annual meeting was not only a feast of industry technology and information, but also an important event for building consensus, boosting confidence, and providing guidance. It fully demonstrated the positive role of the Hunan Provincial Architectural Electrical Society in promoting technological progress in the industry, facilitating the integration of industry, academia, research, and application, and serving local economic development. Based on the corporate development philosophy of "protecting users from lightning strikes," we are committed to the electrical safety of electrical systems and focus on lig...